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HomeMy WebLinkAboutFinal Water Quality Management Plan~a9~c~ / F1NAL WATER QUALITY MANAGEMENT PLAN RORIPAUGH RANCH SPECIFIC PLAN SEPTEMBER 26, 2002 PREPARED BY: ~ Tha Keith Companias~~~ E 22690 Cactus Avenue Moreno Valley, CA 92553 (909) 653-0234 Mr. Kent Norton, AICP PREPARED FOR: Ashby U.S.A., LLC 470 E. Harrison Street Corona, CA 92879 Tel (909) 898-1692 ~ TABLE OF CONTENTS A. INTRODUCTION 1 B. HYDROLOGY STUDIES 5 C. BIOLOGICAL STUDIES 8 D. WATER QUALITY/URBAN RUNOFF 10 E. IMPACTS AND IMPROVEMENTS 12 TO ONSITE DRAINAGES F. PROPOSED WATER QUALITY ACTIONS 19 G. CONCLUSION 26 H. REFERENCES 27 APPENDIX A CONSTRUCTION BMP DETAILS APPENDIX B POST-CONSTRUCTION BMP DETAILS APPENDIX C DRAFT STORM WATER POLLUTION PREVENTION PLAN FOR MASS GRADING N:\3136Tdw\WaterQualityManagement PIan3.doc 2 ' ' A. INTRODUCTION ' Ashby U.S.A., ("hereafter referred to as the "applicanY') proposes to develop the Roripaugh Ranch Specific Plan (hereafter referred to as the "proposed projecY') that ' includes the construction of approximately 2,058 single family residential units on 804.7 acres of land at the northeast comer of the City of Temecula ("City"). Figure 1 shows the regional location of the project, while Figure 2 shows the site location. In addition, ' Figure 3 shows the proposed land plan for the project. A Draft Environmental Impact Report (EIR) was circulated for public comment in April and May of 2002. The City of Temecula is the Lead Agency for the EIR under the California Environmental Quality ' Act (CEQA) of 1970, as amended. A Fi~al EIR is now being prepared and circulated to commenting agencies for their review. City hearings on the project are planned for October-November of 2002. ' This report is intended to satisfy Mitigation Measure 4-9 of the EIR and the State Clean Water Act that require a Water Quality Management Plan (WQMP) for this project. The WQMP requirements are outlined in the National Pollution Discharge Elimination ' System (NPDES) Permit and Waste Discharge Requirements (WDR) issued by the California Regional Water Quality Control Board, San Diego Region, to control azea- wide urban storm water runoff. These documents outline general conditions that should ' be applied to all municipalities that issue discretionary permits for potential land development, such as the proposed project. The latest NPDES/WDR document indicates , that: _ "Prior to the issuance of building permits, permit applicant shall submit for approval of City ... Official(s), a water quality management plan (WQMP) specifically ' identifying Best Management Practices (BMPs) that will be used on site to control predictable pollutant run-off ... The WQMP shall identify the structural and non- structural measures ... detailing implementation of BMPs whenever they are ' applicable to the project, the assignment of long-term maintenance responsibilities, and, shall reference the location of structural BMPs." ' i i h i b nage as n t at s The project site is within the Santa Mazgazita River watershed or dra under the jurisdiction of the San Diego Region of the Regional Water Quality Control ' Boazd (RWQCB). This report is being submitted for review and approval by the RWQCB - San Diego Region, prior to issuance of the first occupancy permit for the proposed project. , The site overlaps the middle-upper reaches (i.e., lower headwaters) of two natural drainage basins, all of which flow to the west. In recent yeazs, runoff from urban areas ' has become an increasing concem of all offices of the RWQCB because it contains a variety of pollutants such as fertilizers, herbicides, animal waste, oil, detergents, and grease. This WQMP is intended to outline ways in which the proposed development can , reduce or eliminate potential urban runoff from the site. , ' ~ 3 FIGURE 1 91 LAKE ~MATHEWS so ~LAKE PERRIS 15 ~ CANYON LAKE 1 , ~-- . ~~ O J~~ ~ LAKE ELSINOR ~~O ~'/ ~~ ~ o ~ ~~ TEMECULA i CITY LIMITS . L--------- i ~ i ~ ~~ ~ _ 60 7~ ~ SKINNER (NORTH) PROJECT LOCATION (SOUTH) ~ RIVERSIDE COUNTY SAN DIEGO COUNIY Tha Kei[~ Campeniesl~A ~~~~ ~ N O T T O 9 C A L E v Roripaug~l ~ Rarlch ~_ ~ - ~ FIGURE 2 Q (~ ~ ~ a--~ .~ U ~ a.-~ U N ~O ~ ~ -- 5 A ;, = - ~ T~e Keith CamOenieal~r + _ '_ _ ~ a . , o s ~ . ~ E .~~c~~ :~~«~~~;~z~~ -. ~~~~11c~~~ ~~ , -o~, --------- UNIMPROVED ROADWAYS IMPROVED ROADWAYS ~ ~ ~ ~ ~ SPECIFIC PLAN BOUNDARY - • - • - • - CITY LIMITS , , ' 1 ' 1 ' ' ' ' ' , ' ' ' ' ' ' ' Related Approvais/Programs The applicant is also processing a Clean Water Act (CWA) Section 404 permit for the project through the U.S. Army Corps of Engineers (ACOE) and a CWA Section 401 Certificatioq through the local RWQCB. This report is consistent with the CWA Section 401/404 materials submitted to the RWQCB in support of this project In addition, most of the Santa Gertrudis Creek channel and associated uplands east of Butterfield Stage Road aze included in the Assessment District 161 Sub-Regional Habitat Conservation Plan (AD 161 SHCP) recently approved by the U.S. Fish and Wildlife Service (USF&WS) and Riverside County. Several documents that were prepazed to support the EIR also support the WQMP, including hydrology reports by The Keith Companies, Ina (TKC) and a wetlands and jurisdictional delineation by the consulting firm of GLA and Associates, Ina (GLA). B. DRAINAGE STUDIES In August of 1998, The Keith Companies (TKC), an engineering consulting firm, prepazed a preliminary hydrology study for the proposed project. The TKC study was based on the rational method as presented in the Riverside County Hydrology Manual. The project site in the northern portion of the San Diego Region (9) of the Regional Water Quality Control Board. The project site is divided into two main areas. The "Valley" is the portion of the site east of Butterfield Stage Road) and comprises two natural drainage channels, Santa Gertrudis Creek and Long Valley Wash. The central portion of the "Valley" is situated in the Santa Gertrudis Creek drainage basin, while the southem portion of the valley is drained by Long Valley Wash. In contrast, the "Plateau" poRion of the site is west of Butterfield Stage Road and does not contain any significant natural channels, however, it does receive runoff from the Rancho Bella Vista property to the north. Onsite runofF and offsite flows from Rancho Bella Vista flow south and west across the "Plateau" through a series of upland swales and shallow drainage channels. The relationship of the project site to regional drainage channels is shown in Figure 4, while runoff entering and exiting the site is shown in Figure 5. Santa Gertrudis Creek has an inlet volume of 2,797 cubic feet per second (cfs) and an outlet volume of 3,075 cfs. Long Valley Wash has an inlet volume of 3,768 cfs and an outlet volume of 4,460 cfs. 5 ~ RE 4 ~ g ~a C~ ~ ~$ Ca ~ L ~ ~ ~ ~ ~ : ~ S ~ p ~ ~ ~~ ~ ~ ~~m ~ ~~/ ~ L.L 8 S S ~ rne Keicn campen~asl~^ ' ~~~~~` ~ ~ ~ . . ~ _ ~ •`-' ~ 1Zoripaubh ` ~, Ranch ~ Sub Areas a , ASHBYUSA,LLC FIGURE 5 ' % ~, ~ / s ~~~ ~ ~., ~ i v J'l\ w' ~ ~ ~ ~~ ' ~ / ~~ ~~ ~ ~ J~ ,~ ,/ ~ ! '°".~~ :~.. .~~ ~~~~ ~ ~o. , ~~ ~ ~~~~ ~~ ; ~ ~ ~ ~~~ ~ ~ ° ` ~ ~~' ~ o 0 ~ , ° '~ ~ , ~~ _ : ~~ 1 : ~~ . . ~~- s ~ ~ ,.. . ` , o :~ ,~~ ~ .~ ~ ; ~ ~ . ~ :~ ~ . ~ ~ ~. ~~ ~~ ~ S ~: ~~~ -~~~ _'~ ~ ~: , ~e~Z_~, i~~~ ~-~ ~ a ~ ~ ~ - •~ , ~ ~ ~' ,~;,, ~ ~ ~ o ~ ~ :` ~ St ~ ~ Q ~~ ~~~f ~v~~ , ~: ~~ : : ~S 1 ~ ~ _ <~ ~ ~~. _ ... _ ~~ ~ , ~ ~ ~, ~ ~ ~ ~ ~~~. e ~ ~ ~ -_ ~ ~ ~ ~ ~ ~ a s,. ~ ` ~~ ~ ~ ~,~ o ,~ o ~ ~ ~~ ~ o N N ~~ i , ~ao3~ ~~_ fb~ ~ V ZO !O ' , ~ `_~"`~~ 3 N Q ~ lL ~ , ~~`WO I I n ~ C C N \ / ~, N N ~ ~ ~ . . ~ J 5 ll.~ LLl ~ ' ' U ~, ~~ .~ ~ ~ a~ ~ ~ ~ ~'~ ~ ~ ~ O , ~ ) ` ~ w g ~ ~ ~ ~ ~ ~ ~,~ °'~ .~ :.o ~ i T ~ ~ ~ ~ ~ ~ ~ ~, ~ _~ ~~ ~o ~ ~~ ~X ~ W~ ~ ~ ~T~ T~e Kaith Companiesl~A ~ N O T T O S C A L E ' v Roripaugh , Rarich I ~ ~ t ~ RE 6 AD 161 Habitat ,~-~- e~ - - Pond N~ ~~ e •~ ~ ~ ~ ~ ~ ~ _ ~~ o~ Uw ~ ~ ~ O ~ lV ~ W}~~ V^'/ ~ W ~ ~ Total Acres ;,~%;j~;~~~Et~'; Riversidian Sa9e Saub 165.3 Acres - TranSitlonal 58.6 Atfes - G2sslantl 24.9 Acies _ Ripanan 24.6 Acres wootllana ZB Acres ~ 'Others 523.5 Acres TOTAL - 804.7 AaeS .. 'Ruderel, Weedy, Agricultural, Gratletl and Developetl /'~ _ ~ ~~ I ~ , ~ ~ ~ _ _ I • ~ ~ ~o 60. o ~ . , ~ v ~0 R~"!u~ ~tu~ .,. ~s_ i ~f~~.tlM~i q~~f. ~ `~'~F'. ~ ~ Source: Natural Resource T~e Keic~ Compeniesl~A V o ~ .~ ~ ,~ ~- - ~~ r i 1Zoripau~h~ ~, Ranch ~ 1 ~ ~ ~ ~ ~ ~ I ~ ~ e ~O I , I i ~P;'.1.~. ~ ~ ~ I ~ S Fpn May 1999 ~~ ~ , C. BIOLOGICAL STUDIES ' In May of 1999, the consulting firm ofNatural Resource Consultants (NRC) prepared an assessment of biological resources for the project site. Figure 6 summarizes the vegetational communities found onsite. The NRC report found the site supported the ' California gnatcatcher (Polioptil[ia californica californica) and the Quino checkerspot butterfly (Euphydryas editha guino) in addition to other sensitive plant and animal -, species. In 2000, Assessment District 161 Sub-Regional Habitat Conservation Plan (AD 161 SHCP) was approved by the U.S. Fish and Wildlife Seroice (USF&WS) and Riverside County. This SHCP covers most of the drainage along Santa Gertrudis Creek ' east of Butte~eld Stage Road, which has been incorporated into the land plan for the Roripaugh project . In February of 2001, the consulting firm of Glenn Lukos Associates, Ina (GLA) was , retained by the applicant to prepaze a Wetlands and Jurisdictional Delineation study for the project site (GLA 2001a). This report determined that the site contains the following: ' • 10.0 acres of land under the jurisdiction of the U.S. Army Corps of Engineers (ACOE) considered "waters of the U.S" of which 3.38 acres ' will be impacted by the project; • 0.8 acres of wetlands (also "waters of the U.S.") under ACOE jurisdiction , of which 0.50 acres will be impacted by the project; a~d • 3.38 acres of riparian ("streamside") habitat above the ordinary high water ' mark (OHWM) that are under CDF&G jurisdiction of which 0.83 acres will be removed by the project. ' The GLA study also identified several native vegetational types, some of which aze associated with the various drainage channels onsite. The main drainage channels onsite support alluvial fan sage scrub and riparian woodland vegetation, interspersed with ' willow woodland and mulefat scrub. GLA also prepared a conceptual mitigation plan to address these impacts (GLA 2001b). ' It should also be noted that, accord'mg to a regional soil survey prepared by the U.S. Soil Conservation Service (now the Natural Resource Conservation Service), soils on the ' project site are moderately susceptible to erosion by wind and water, especially when exposed such as when vegetation is removed by development (SCS 1963). 'J ' * Ordinary High Water Mazk ' ' \0 a 1 ' D. WATER QUALITY/URBAN RUNOFF ' State and regional agencies responsible for surface and groundwater quality have become increasingly concerned about "urban runoff' which is the runoff from azeas developed for ' human use (e.g., parking lots, residential development, streets, etc.). This urban runoff contains chemicals that can pollutant natural drainage channels, local surface water bodies, and groundwater resources. Typical constituents include the following: ' • fertilizers and pesticides applied to residential lawns or landscaped planters/medians in commercial or industrial azeas; 1 . oil, grease, and other automotive fluids from vehicle maintenance; • animal wastes, lawn clippings, and other yard wastes swept or hosed into the gutter from individual homes; and ' • trash and other windblown materials that aze deposited in gutters and end up in the storm drain system. ' These chemicals and other materials are regularly flushed into the storm drain system, not only during storm events, but more commonly by nuisance runoff from overwatering of lawns and other landscaped azeas. In more urbanized areas, these pollutants go directly ' into a piped storm drain system and may eventually be carried to the ocean or major rivers. In outlying rural areas, these pollutants are typically deposited near the point of discharge into natural drainage courses. They may or may not be transported further ~. down the channel, depending on the time of year, amount of deposition, and timing of ]ocal storm events. ' Urban runoff also contains an increased amount of sediment compared to natural runoff. Sediment consists of soil particles (e.g., sand, silt, etc.) that aze eroded or carried away by , moving water and are deposited wherever the water slows down to the point it can not longer physically carry the particular particle (i.e., lighter particles such as silt aze carried further, or at lower velocities, than larger, heavier sand particles). During the natural , water cycle, storm runoff carries s'ome amount of sediment into natural drainage channels. These channels change over time as sediments are deposited and eventually change the flow of the channel. ' Development of the land often disturbs natural slopes or level ground, which then exposes natural soils to erosion by wind and water. These soils would normally be ' protected by natural vegetation, but disturbance and subsequent rain or wind may cause widespread erosion. Development also increases the amount of runoff by covering over relatively pervious native ground with impervious surfaces such as asphalt and concrete. ' Development not only increases the amount of runoff but it can also increase the velociry at which the runoff travels by creating long conveyances such as along gutfers or in storm drains. Water traveling at higher speed can erode or scour more soil away when it ' dischazges into natural channels. ' `v , io ' ' In these ways, man-made development can change the natural cycle of local drainage channels by increasing the amount and velocity of runoff, increasing the amount of ' - sediment and/or the location that sediments are deposited within the drainage channel. If development exposes a large amount of native soil to increased erosion, and creates large azeas of impervious surfaces, a considerable amount of sediment can be generated during ' storms, which is then carried to and deposited in local drainage channels, usually where storm drains initially discharge into the natural channel. ' Sedimentation and urban pollutants from this development can generally be controlled with a combination of special design features and Best Management Practices (BMPs), , most of which control erosion during and after construction. Section F of this report outlines the BMPs recommended for this project. ' The County requires a certain level of information or detail at specific steps in their development approval process. Detailed engineering design of drainage facilities and scouring/sedimentation transport reports are not typically required at the Specific Plan ' and Environmental Impact Report stage, partly due to cost but also because the location or design of these facilities could change significantly during the EIR process. ' These detailed designs and reports aze normally required during final engineering and prior to approval of final maps. However, it is possible at this stage to identify potential environmental impacts and recommend general design guidelines for drainage facilities ' that will prevent significant water quality impacts. The more specialized studies will recommend specific design features and may identify additional BMPs. For example, the proposed detention basin on Long Valley Wash is the "flow-by" type that will not hinder ' low flows but will only remove the "peak" flows during major storms. Sediment build- up will be controlled by appropriate maintenance of this basin as needed. ' The project will have no negative impacts on groundwater quality or quantity. The proposed water quality control devices will remove the sediment and chemical constituents of urban runoff before it reaches the detention basins, the surface water , recharging to the ground water should be relatively free of urban pollutants. ~ ' ' ' 1 ' 11 ~3 0 1 1 ~ ' 1 ' ' , ' ' ' ' , , ' , LI ' E. IMPACTS AND IMPROVEMENTS TO ONSITE DRAINAGES In September of 2001, the applicanYs consultants met with RWQCB staff to discuss the project site and the proposed development plan. At that time, RWQCB staff requested a number of changes to the project, including the use of biofilters and eliminating horse trails in the creek channel that had been requested by the City of Temecula. On August 19, 2002, the applicant's consultants again met with RWQCB staff to explain how the current land plan complies with the requested changes. The following section describes how the proposed project will impact Santa Gertrudis Creek, Long Valley Wash, and the Plateau area. This section also generally describes the proposed flood control improvements that will affect water quality. Santa Gertrudis Creek The Santa Gertrudis Creek drainage and its associated biological resources will be preserved in their entirety with the exception of a 2,200-foot long section on either side of Butterfield Stage Road. This section of the creek has been physically degraded over the yeazs by vehicle crossing, a former vehicle maintenance facility, and limited historical collection of sand and gravel in this portion of the channel. This section also has no significant biological resources. The project will place rip-rap along the eastem slope of Butterfield Stage Road to protect this regional arterial from erosion. A 0.7-acre detention basin will be constructed in the southwest comer of Planning Area 14 next just east of Butterfield Stage Road to keep offsite runoff at approximately its current volume, and to prevent downstream erosion or flooding impacts. The portion of the creek crossing under Butterfield Stage Road will be a con-arch bridge with a concrete bottom to minimize maintenance under the roadway. The 900-foot section of the creek west of Butterfield Stage Road will have a soft-bottom channel protected with armorflex along the banks. In addition, the armorflex will be hydroseeded as requested by RWQCB. The portions of the creek both upstream and downstream of these proposed improvements will remain in their existing condition except for an approximately 10-acre mitigation area in the upstream portion, in compliance with the projecYs CWA 401/404 applications. This site will mitigate the loss of wetland and riparian resources, mainly by improvements along Long Valley Wash. The location of this site is subject to ongoing negotiations with the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, and the California Department of Fish and Game, and is documented in the recent reports by GLA (2002a, 2002b). Long Valley Wash The onsite portion of this channel has been extremely degraded by historical fanning. activities. At present, it has a sandy bottom but is relatively narrow and its banks range in height from a few inches to several feet. During high flows, runoff spreads out along the banks across the southern "Valley" portion of the site east of Butte~eld Stage Road. The channel has more definition west of the proposed road alignment until it eventually 12 ~~ LJ ' merges with Santa Gertrudis Creek about 0.6-mile west of the project site, near the ' intersection ofNicolas Road and Calle Girasol. The proposed project will widen this channel to approximately 200 feet with a soft ' bottom and armorflex along the banks. In addition, the armorflex will be hydroseeded as requested by RWQCB. A 3.2-acre "flow-by" detention basin will be constructed in Planning Area 25, neaz the upper or eastem end of the wash, to provide flood protection ' to the "Valley" portion of the site. Trails for pedestrians and bicyclists (no horses) will be constructed along both banks, ' with landscaping or retaining walls separating them from the adjacent residential uses. The channel will also be separated from the trails by fencing to discourage entry into the channel. A pedestrian bridge is proposed to span the wash to allow residents living south ' of the channel to access the community pazk and schools proposed on the north side of the channel. ' 'The City of Temecula originally requested horse trails within the creek channels onsite. However, the applicant has moved them out the channels and they now run along the south and east boundaries of the site. Horses and their riders will be allowed to cross the , creek at only one specified location along the channel (i.e., just west of the eastem boundary of the site). The HOA will own and maintain these trails, and will post signs on both sides of this crossing prohibiting riders from traveling along the channel. The ' HOA will remove horse manure from this crossing on a bi-we~kly basis (i.e., twice a month) and remove it monthly from the rest of the horse trails. ' Runoff from all of the development areas, including the horse trails, will be directed into grassy swales for biofiltration prior to dischazge into the wash. The only exceptions will be "clean" runoff from rural areas adjacent to the east and southeast boundaries of the ' site, which will be directed into the proposed flow-by basin at the upper end of the wash before it enters Long Valley Wash. Another small azea of "clean" offsite runoff will be passed through the site near the southwest comer of Planning Area 21, just east of ' Butte~eld Stage Road. This runoff will have to be mixed with urban runofF from Planning Area 21 but will pass through fossil filters in the storm drains prior to discharge into Long Valley Wash just west of Butterfield Stage Road. , Central Area ' The portion of the site west of Butte~eld Stage Road to the MWD pipeline properry/easement will drain toward Nicolas Road, and urban runoff from Planning Areas ' I1, 12, and 33 will be treated by a detention basin with siltation forebay prior to discharge to a storm drain in Nicolas Road. ' , ~ ~h ' 13 ~~ , Plateau Area ' This area does not contain any significant natural drainage channels, although it does contain a number of upland swales. Normal surFace runoff from this area does not reach Santa Gertrudis Creek directly, but does flow south and west off the plateau toward the ' creek. During heavy flows, runoff may travel along or cross Nicolas Road to reach the creek. ' The project proposes a number of landscaped paseos in this area, some of which may provide biofiltration for localized runoff. However, the project proposes two detention t basins (Planning Areas 7B and 7C) to provide the majority of "first flush" treatment of urban runoff from the proposed development. In addition, approximately a dozen fossil filters are proposed in the storm drains along Murrieta Hot Springs Road to help treat , runoff from the roadway. Summary ' The proposed grading of the project will generally maintain the existing historic drainage pattems onsite. The project will collect and convey runoff through the developed areas , via a combination of grassy swales, street curbs and gutters, and storm drains that eventually connect to natural drainage channels. Five (5) onsite detention basins are proposed to maintain offsite ]00-yeaz storm flows at or below existing levels. These ' detention basins will be designed and graded per Riverside County Water Conservation and Flood Control District standards. Two of the basins are located in the Plateau area, while the other two aze located in the Valley area. The conceptual drainage master plari ' for the project is shown in Figure 7. The proposed water quality control measures for the project aze summazized in Figure 8. They include grassy swales for biofiltration wherever possible and needed, and fossil filters in storm drains where biofiltration is not ' possible. Figure 9 also shows the conceptual design of the proposed detention basins, while Figure 10 shows a cross section of the proposed improvements along Long Valley Wash. ~~ ,, , ' ' ~ ~ ~~ , 14 ' ' F. PROPOSED WATER QUALITY ACTIONS , The following construction and post-construction BMPs are intended to meet the requirements of the State Clean Water Act and the San Diego Region of the Regional 1 Water Quality Control Board. Construction BMPs , These measures include combinations of sandbagging, silt fencing, silt dams, slope protection and other devices as required to prevent discharge of silt, sediment or urban ' runoff during construction. Prior to final map approval, erosion control plans and Storm Water Pollution Prevention Program (SWPPP) reports will be written to control erosion and silt transportation, and to document implementation of this WQMP. Table 1 ' summarizes the various construction BMPs planned for project construction, not including mass grading, while Appendix A contains details of most of these measures. In addition, a copy of the draft SWPPP prepared specifically for mass grading activities on ~ the project site is included in Appendix C of this document. Implementation of these measures will help reduce the potential deposition of sediment in ' the local drainage channels in excess of what would be deposited under natural conditions. During all construction activities associated with this project, the developer shall conduct procedures and install devices to protect local water quality consist with ' BMPs OD SEC 1- Source Control, OD SEC 2- Sediment Minimization, and ESC 1- Scheduling (of soil movement). ' At the onset of grading a number of ineasures shall be implemented in appropriate locations so as to minimize the transport of sediment out of construction areas and into the natural drainage channels that are to remain relatively intact (e.g., the lower portion of ' Channel A). As required in BMP OD SEC 3, the developer sha11 control runoff from offsite areas that comes onto the project site and that passes over disturbed areas. As required by OD SEC 8, an appropriate staging azea will be selected for the storage of , landscape plants until they can be planted, however, no location ~as been selected yet. Runoff from disturbed azeas shall be controlled via several BMPs as appropriate, ' including OD SEC 4- Disturbed Areas, and OD SEC 5- Bubble Up Basin. In addition, combinations of ESC - 10, Seeding and Planting ESC - 11, Mulching, and ESC -20, Geotextiles and Mats, can reduce local erosion by up to 95 percent compazed to bare ' ground. During construction, runoff along project roads will be controlled by the placement of silt fences (ESC-50), Straw Bale Barriers (ESC 51), and Sand Bag Barriers ' (ESC 52) along the roadways and/or across the roadways at approximately 100-foot intervals, as needed, to control sediment-laden water from construction azeas. In addition, ESC 32 - Slope Drains, and ESC 40 - Outlet Protection, shall be used where ' slopes over ten feet are created. ' , 19 ~~ , ' ' ~ ' ' , ' ' ~ ' ' , , ' ~ , ' , ' Table 1 Construction Best Management Practices (BMPs) BMP Number/Title* General Descri tion OD SEC 1: Controlling erosion at the source. This will be a Source Control key consideration for all construction activities throu hout the srte. OD SEC 2: Attenuating sediment from leaving the site. This Sediment Minimization will be a key consideration for all construction activities throu hout the site. OD SEC 3: Diverting off-site run-on from passing over Run-on disturbed areas. See related BMPs ESC 31, ESC 32, ESC 50, and ESC 52. This will be a key consideration for all construction actfvities throughout the site, especially from the Yalley partion of the site that drains toward Long Valley Wash. OD SEC 4: Stabilizing disturbed areas with a vaziety of BMPs. Disturbed Areas See related BMPs ESC 31, ESC 32, ESC 50, and ESC 52. This will be a key consideration for all construction activities throu hout the srte. OD SEC 5: Detaining sediment-laden runoff: These will be Bubble-Up Basin used if needed near embankments for temporary detention basins, i needed. OD SEC 6: Controlling dust and erosion from blasting Blasting activities. Some blasting may occur as part of this project, and any such activities will be controlled so they will not cause erosion or runoff to reach existin channels. OD SEC 7: Governing the use of BMPs not discussed in this Alternative BMPs report. Typically requires owner approval, but this project will obtain approval from RWQCB prior to usin alternative BMPs on this site. OD SEC 8: Requiring staging within a sandbag-bermed area of Landscape Staging Area plants intended for landscaping to contain, in a localized area, any sediment transported in runoff from plant watering. No area has been selected yet but this measure will be implemented if and when such an area is desi ated YVPPP ESC 1: Scheduling Sequencing the project to reduce the amount and duration of soil exposed. This general measure will be used as a guide when planning construction activities to minimize erosion and runo . 20 ~ ' ' ' ' , t ' ~ ' ' ' ' ' ' L1 1 ' Ir J BMP Number/Title* General Descri tion ESC 2: Controlling erosion through preserving existing Preserve Existing Vegetation trees, shrubs, and/or grasses. Existing plants shall be preserved as practical, especially within or adjacent to major drainage channels. Large native shrubs and trees that can be transplanted ivill be reutrlized onsite whenever ractical. ESC 10: Stabilizing soil with vegetation including Seeding and Planting hydroseeding, trees, shrubs, sod, etc. Areas of exposed soil in excess of 1, 000 sguare feet shall be temporarily planted or otherwise stabilized within 1 week of disturbance and maintained until ermanent develo ment is com leted. ESC 11: Stabilizing soil with mulch, soil binders, and Mulching sealants. Areas of exposed soil in excess of 1,000 sguare feet shall be mulched or otherwise stabilized within 1 week of disturbance and maintained until ermanent develo ment is com leted. ESC 20: Stabilizing soils with erosion matting of natural and Geotextiles and Mats synthetic materials. Areas of exposed soil in excess of 1,000 square feet shall be stabilized in this or a similar manner within 1 week of disturbance and maintained until permanent development is com leted. ESC 21: Controlling fugitive dust primazily through Dust Controls watering and street sweeping. These activities shall be implemented throughout the constructron rocess on the site. ESC 22: Providing for construction access over streams with Temporary Stream Crossing culverts, fords, or bridges. Construction of the site wrll require a centralized crossing of Santa Gertrudis Creek. This crossing will be in the disturbed area adjacent to Butterfield Stage Road to minimize impacts to natura! areas. Due to the disturbed nature of Long Valley Wash, this channel may have several dry-season temporary crossings but wrll ultimatel be im roved to 11 width. ~ ESC 23: Stabilizing vehicle routes through watering, berms, Construction Road Stabilization or paving. This shall be implemented throughout the construction rocess. ESC 24: Stabilizing points of ingress and egress and points Stabilize Construction Entrance where paved and unpaved roads meet. This shall be implemented throughaut the construction _ ~rocess._ _ _ , 2 ~ ~' ' ' i , ' ' , ' t ~ ' , ~ ' ' t ' CI BMP Number/Title* General Descri tion ESC 30: Managing runoff, desilting, or channeling water Earth Dike with earthen berms. This shall be used as necessary in conjunction with other erosion control ' measures to channel and control sediments and runo . ESC 31: Managing off-site run-on and on-site runoff Temporary Drains and Swales through stabilized channels. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runo . ESC 32: Draining slopes and channeling water with pipe Slope Drain drops, downdrains, or V-ditches. This shall be used where temporary slopes are created during construction. ESC 40: Stabilizing drain outlets with rock and other Outlet Protection velocity and erosion reducing devices. This shall be used where temporary slopes are created during construction in con unction with ESC 32. ESC 41: Reducing the velocity of water with berms and Check Dams sandbag dikes. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runo . ESC 42: Reducing runoff velocity and trapping sediment by Slope Roughening/Terracing creating microclimates and increasing infiltration and sedimentation. This shall be used as necessary on slopes over ten feet in length and in conjunction with other erosron control measures to channel and control seddments and runa . ESC 50: Detaining sediment-laden water with, primarily, Silt Fence fabric fencing or fencing combined with sandbags. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and rano . ESC 51: Detaining sediment-laden water with straw bales. Straw Bale Barriers This shall be used as necessary in conjunction with other erosdon control measures to channel and control sediments and runo . ESC 52: Detaining sediment-laden water and preventing Sand Bag Barrier hazazdous material runoff with sandbag barriers. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runo . ' zZ 2v C~ [~ , ' ' , ' ' ' ' t BMP Number/Title* General Descri tion ESC 53: Reducing velocity of storm water and increasing Brush or Rock Filter sedimentation with vegetative or rock filters. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runo . ESC 54: Detaining sediment-laden water with straw and/or Storm Drain Inlet Protection sandbag barriers. This shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runo . ESC 55: Providing sedimentation with excavated bermed Sediment Trap areas. This shall be used as necessary in conjunction ivith other erosion control measures to channel and control sediments and runoff. These shall not be used !n areas planned for permanent detention basins. ESC 56: Retaining and detaining sediment laden water. This Sediment Basin shall be used as necessary in conjunction with other erosion control measures to channel and control sediments and runoff.' These should be located in areas planned for permanent detention basins. CA 40: Stressing the importance of employee training and Employee/Subcontractor requiring bilingual training when appropriate. The Training applicant tivill assure that adequate training is offered both before and during construction so all workers are aware of and follow the WQMP re uirements. ' * OD = owner designed , ' , , ' ' ESC = erosion & sedimentation control CA = state required ' 23 ~ , ' Post-Construction BMPs (PC-BMPs) ' These measures include maintenance of sediment collection, water quality swales, and detention structures that will be part of the permanent development. Figures 9 and 10 show where these various measures are proposed to be installed. These measures are ' designed to minimize the deposition of excessive sediment, chemicals, and other water pollutants associated with urban runoff. ' l. Maintenance - All drainage facilities within public right-of-way shall be maintained by the City of Temecula Public Works Department, as approved by the Riverside County ' Flood Control and Water Conservation District (RCFCWCD). All drainage and water quality facilities outside of public rights-of-way shall be maintained by a Home Owners Association (HOA). The 4 detention basins shall be maintained by the HOA. Fossil , filters in various storm drains shall be maintained by the HOA, including those in public rights-of-way subject to a reimbursement agreement with the City. The HOA shall be established prior to issuance of the final occupancy permit for the project. Until such ' time as the HOA can be established and adequately funded and conduct maintenance activities, all such maintenance shall be the responsibility of the applicant. , The HOA will own and maintain the onsite horse trail along the south and east boundazies ofthe property, including a specified crossing of Long Valley Wash just west of the eastern boundary of the site. The HOA will post and maintain signs on both sides ' of the crossing prohibiting riders from traveling east or west along the wash. In addition, the HOA will remove horse manure from this crossing bi-monthly and from the rest of the trails on a monthly basis. ' These activities will provide the following water qualiry benefits: 1) keep the various structures and facilities in good repair so they can function properly; 2) prevent the buildup of excessive amounts of sediment from storm drain inlet structures before they ' can be washed into the storm drain system; 3) maintain fossil filters so they can remove chemicals and other pollutants associated with urban runoff: ' It should be noted that maintenance is a key component to ongoing water quality control. The proper operation of grassy swales, fossil filters, the storm drain outlet filters, etc. , depends on their being regularly checked and maintained to keep them operating as designed or as indicated in their design specifications. Failure to support an adequate maintenance program will substantially reduce the effectiveness of this Water Quality , Management Plan. The CC&Rs goveming the project should contain language such that, if the RWQCB finds the water quality control facilitieslprograms of the project to be ineffective or not being properly maintained, the HOA will act immediately to correct ' identified problems. This language should not be able to be changed by the HOA without approval of the RWQCB. ' 2. Street Sweeping - Project streets shall be swept at least once a month using vacuum- assisted dry sweepers which can remove 50-88 percent of urban pollutant constituents (LA Times 2001- see Appendix B). Mechanical broom or wet-vacuum sweeping cannot ' ' 2a ~ ' ~ be substituted for the proposed method. This service will be provided, either direcUy or contracted, by Riverside County on public streets, and by the HOA on private streets ' and/or parking lots. This activity will provide the following water quality benefits. It will help reduce wind- ' blown dust particles which become sediment when washed into storm drains. These particles often contain other types of urban pollutants, such as brake dust, particulates wom from car tires, etc. Sweeping can therefore serve a dual role of removing sediment , and potential chemical pollutants. It can also help reduce light trash, grass clippings, and sometimes dried animal waste that has been deposited in the gutter. Removal of this , material can substantially reduce sources of "dry" urban pollutants before they can be washed into the storm drain system and become liquid contaminants. , 3. Detention Basins - As much as possible, the 4 detention basins shall be designed to function similaz to "constructed wetlands" (TC 3) or "enhanced wet ponds" (TC 2) as ouUined by the California Storm Water Best Management Practices Handbook ' (Califomia 1993). However, these basins will be intermittent and not have a permanent surface water due to local runoff conditions. While their primary function is to temporarily detain 100-year storm runoff to prevent downstream impacts, these basins ' shall also be designed to help maintain local water quality mainly by reducing the offsite transport of excessive amounts of sediment. ' The two basins in the Plateau area will be regulazly maintained (i.e., cleaned) to keep sediment from building up in the basins. These basins will also allow increased percolation of surface flows into local groundwater, and will help maintain surface and ' groundwater quality. The design of the basins shall be based on consultation with the local office of the Regional Water Quality Control Boazd, Santa Ana Region. Maintenance of the basins will be conducted regularly (i.e., at least annually) and will be ' inspected as soon as practical after measurable precipitation to determine if repair or other maintenance is needed. Any significant amount of Arundo (a large "bamboo"-like plant) that can supplant beneficial riparian or wetland species will be removed as needed , to keep the basins clear. 4. "Clean" Storm Drain Inlets - All storm drain inlets that receive runoff from natural ' open space azeas shall be designed to reduce flow velocity and trap sediments prior to entering the underground storm drain system. The main water quality benefit of these inlets will be the removal of sediment before it reaches the storm drain system. Any ' storm drains that convey urban runoff directly offsite shall have fossil filters installed and regulazly maintained by the HOA according to manufacturer's specifications. Maintenance will be conducted regulazly (i.e., at least monthly during dry periods and as ' soon as practical after measurable precipitation), and will include removal of sediments, weeds, and trash. , 5. Grassy Swales - The project has been designed with several dozen landscaped paseos and grassy swales to provide biofiltration (i.e., help filter urban runoff and associated pollutants) during periods of low flow. These swales are described by the U.S. Office of ' ' 25 2S ' r ' ' , ' 1 ' ' ' ' ' , ' , ' ' ' ' Wastewater Management (U.S. EPA Website) or swale type "biofilters" described as TC 4 by the California Storm Water Best Management Practices Handbook (Califomia 1993). These "filter swales" have been designed according to current industry standards (IECA 1997, Kristar 2001) regazding lengih, width, slope, depth, grass type, etc. Appendix B contains design criteria for these facilities. These sWctures will provide several water quality benefits by removing excessive sediment and concentrating and isolating urban pollutants in the grassy swale areas where they can be easily removed if necessary. These filter swales should also be protected from significant storm events while maintaining their primary filter function. Maintenance will be conducted regularly (i.e., at least monthly during dry periods and as soon as practical after measurable precipitation), and will include removal of sediments, weeds, and trash (see Appendix B for details on these types of filters). 6. Storm Drain Downdrains - A number of downdrains will have fossil filters installed to trap urban pollutants. These will also be used for drains that collect runoff from large areas and discharge into the major drainages close to detention basins or near important biological resources. In this way, they will act as a pre-treatment filter for the storm drain outlet filters (see Appendix B for details on these types of filters). There are approximately 12 locations where these filters are proposed for this project. These filters provide a very important water quality function in that they trap chemicals a~d other urban pollutants and prevent them from entering the storm drain system. Mainteuance Responsibilities Major drainage facilities will be approved by the Riverside County Flood Control and Water Conservation District (RCFCWCD) but will be maintained by the developer initially, then eventually by a private Homeowners Association (HOA). There will also be a number of storm drain facilities (i.e., fossil filters) that will be within public right-of- way that will be maintained by the City of Temecula Public Works Depar[ment but will be funded by the project HOA. All of the improvements, BMPs, and other activities identified in this report will be incorporated into the Covenants, Codes, and Restrictions (CC&Rs) to be adopted by the HOA prior to issuance of the fmal occupancy permit for this project. Until the HOA is established, the developer shall be responsible for maintaining onsite drainage facilities. The HOA will be required to obtain approval from the RWQCB to eliminate or modify any CC&Rs dealing with water quality. Maintenance responsibilities for individual drainage facilities will be determined upon filing of individual tract maps. G. CONCLUSION Implementation of the proposed construction and post-construction Best Management Practices (BMPs) for this project, as outlined in this document, will protect local surface and groundwater quality to the greatest degree practical. With proper maintenance of facilities, street sweeping, and replacement of oak trees, the proposed project is not expected to have any significant impacts on water quality. ~~ 26 ~J , H. REFERENCES ' " California Storm Water Best Management Practices Handbooks, Califomia, State of. Construction Acliviry. " Stormwater Quality Task Force. March 1993. , " " Intemational Erosion Control Association (IECA). Proceedings of Conference 32. February 5-9, 2001. Las Vegas, Nevada. ' " " Performance and Condition of Biofilters rn the Pacific Northwesz Article 112. ~ "Performance of Dry and Wet Biofilters Investigated in Seatle. " Article 117. , King County, Department of Natural Resources. "Surface Water Desrgn Manual, King County Washington " August 1997 (draft) , . . ' "Small Site Drainage Requirements (Appendix C)." "Erosion and Sediment Control Standazds (Appendix D)." ' Kristaz Enterprises, Ina "Fossil Filter Stormwater Filtration Systems - Design Standards. " Collection of design specification guidelines. 2001. ' Los Angeles Times (LA Times). "Street Sweepers Do Dirry Work in Runoff Battle. " September 23, 2001. ' Glenn Lukos Associates, Ina (GLA). "Jurisdictional Delineation of Roripaugh Ranch, ` Riverside County, California. " February 14, 2001. ' " Amendment Package for the 401 Water Quality Glenn Lukos Associates, Ina (GLA). Certif:cation for the Roripaugh Ranch Residential Development Project, City of ' Temecula, Riverside Counry, California. " July 25, 2002a Glen Lukos Associates, Ina (GLA). "Conceptual Mitigation Plan for Impacts to Areas ' withi the Jurisdiction of the U.S. Arnry Corps of Engineers Pursuant to Section 404 of the Clean Water Act... " July 25, 2002b. , The Keith Companies, Ina (TKC). "Spec~c Plan Drainage Report for Roripaugh Ranch, Temecula, California. " August 1998. ' The Keith Companies, Ina (TKC). "2"d Revised Draft Environmental Impact Report, Roripaugh Ranch Spec~c Plan. " SCH# 97121030 April 1, 2002. ' The Keith Companies, Inc. (TKC). "2nd Revised Final Environmental Impact Report for the Roripaugh Ranch Specific Plon. "(Draft) August 16 2002. t Z~ ' z~ ' I' ` Natural Resource Consultants (NRC). Biological Resources Assessment of the Approximately 799-Acre Roripaugh Ranch Site Located in the County of Riverside, ' California. " May 1999. U.S. Environmental Protection Agency (USEPA). "Grassed Swales. " Office of ' Wastewater Management. August 6, 2001 . U.S. Soil Conservation Service (SCS). "Soil Survey for Western Riverside County. ° , U.S. Department of Agriculture. 1963. 1 ' r ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ' 2g v~ Infornwl fandscape _ Slopes Native Spuics Private Pedesfrion Acccu Path To Tnil For Plannirg Areas 22, 23 6 24. View Fendrg (See Figure 2-16) ProposeA Ruidvntid Development ~ InformalLana Slopes Native Priwte Pedetirian AtcesS Path To Trnil At Communily Sports Pork, Plannirg Area 27: Middle School, Plannirg Area 28; dustu Housirg. Plannirg Area 31 urid Single Lot Hausing, Pkrmirg Area 18. Yew Fencirg (See Figure 2-16) Proposed Residrstial Development FlaodCOnirofl I I ~ IFIoodCOnirol Accexs Road 6 Acceu Rood 6 ' Private Private Pedestriw . Pedestrian Trnil . . Troil ~ ~ 4' High Chain Link Fence-~~ ~ 4' High CFain Unk Fence _. ... ... ~ \~ ! ~Pedesirian Bridge Rivu Walk~ ~ ~ 2:151opeJ ~P~`= 3` AL Pwirg Over ~ Lompacted Native Soil Armorflez Slope Stabilizer. 2:1 Slope View Fvncirg See Fiyu~e 2-16) Pilaster o ° ie Project Wall F~ 5X Ma o i P°„° J ~ (Su Figure 4-38) / Landirg J Concrete Wulk 6' High Lurb - Londirg - Yew Fence - (Ste Figure 2-: a 4' High Chain Link Fence 0 Flood Conhrol Access Road D6 0 End of Trail - ~~~//~~~~ County Flood ~ ~/ Acceu 6ate ~~/~/ 4' High o jjj j/ G11ainL'nkFe \ i/~//,~ AC Gwirg End Ai Pateo -/ For Plarmirg Area 22 (~~~ Armorflex Slope STabilfzrr. ~ 2:i 51ape The Keich Companleel~~ • 1 ~ ~ « -r~ T ~~ s ~ ~ ~~ IZorlpau~h , Ranch Lorg Valley Creek ~ ~'~ ~ 2: 1 Siope ~ 3` AC Pwirg Over Gompncted Nafive Sail Nafural Bottom I~ Armorflex Slope Stabilizu. ~ 2:1 Slape I NOTE; 1. Trail And Bridge HOA Maintained. 2. CMnnel Maintained By Flood Conirol D~sirict Undes~ Contract To HOA I I View Fencing At Communiry Sports Pork I . . I ~nd 5~hoa~. ~ o ~ a o Project Woll Flood Control 57 Myc 0 Access Road I i 0 Card Keyed 6ate At D 6 ~ Sporfs Park d Schools 5 Pilostu ~ 0 Lw~ding e ;a ; ~~rete Wa~k EM af Tnif . 08 ^>° o ~ " . ° e msa ~ High Lurb 6 i ~ Landf~9 ty Flood CoMrol A~/ j~ ~ I Access 6ate 4' H h ~~~~~ ~ ~ I ig ~% j~j/ ° m mk ence I/ r~~ j 1` _ Arnwrfiax Slope-1 AC Pavirg End Ai Park Stabilizer. 2:1 Slope AcctsS Ramp ~~ ~~ N~ N`~ / : O ~ L ~ ~r~ 1.~ } ~ ~ VJ ~ ~ ~ W ~ ~ ~ ~ O J 1 ~ O U f~n V J V! 0 U ~ Figure 9b Detention Basin Design Long Valley Wash (Planning Area 25) KEY MAP ^~ i' = 3000' ~ ' , , 1 ~:~~~~ 1 ~~ ~. \ ~~ :~ ~. i \ '~, \ , ~ ~ I ~ ;` . ' ` ~ i~ j '\ ~ i ':~ , t ~\ I ' \ ~t ~, ~ ' i ~ 1 ~ }~ i \ . ' ' . \ \ ! yp~f i \Df: i ~. 1 ~ ~• ; ,-=UND. 1 ~ I =D£V. R il ~ ' ~ I i~ ' ~ 1 ' I , ' j ~- ; '~ I ~ i '~ i 'I ~ ~u I m ~ Figure 9c Detention Basin Design Western Plateau Area (Planning Area 7B) PE ~ ~ KEY MAP ~~ 3~ t' = 3000' , ' Figure 9d t Detention Basin Design ~ Central Plateau Area (Planning Area 7C) ~ANDSCAPED ' ~r KEY MAP t' = 3000' . . ~ I I ~ 1 ~ 1 ~ ~ ~ , .~ , 1 ~ I 1 ~ `' ~ ~ , 1 ~ l ~ / ' , ' ' ~ ' ir ii i ii ii ii ~ i. ~ ~~ ~ ~ ' ~~ 1 ~ -- ,, - ~ ~- - l -I~ - T ~ - ~ i i r i ~ ~ ~ / ~~~ ~ ~ / ~ , ~ ,' ~ 7 / '~ Figure 9a Detention Basin Design Santa Gertrudis Creek (Planning Area 27) i I ~/ ~ i ~ II ~ / ~f'~~~9 . ., 3'~ 1 ' ' , ' ' t ' ' 1 ' j ' ~ ' r ~ ~ ' ' } ~ Proposed Best Management Pracfices BMP NumberlTitle" General Description OD SEC 1: Source Control . Controlling erosion at the source. OD SEC 2: Sediment Minimization Attenuating sediment from leaving the site. - OD SEC 3: Run-on Diverting off-site run-on from passing over disturbed areas. OD SEC 4: Disturbed Areas Stabiiizing disturbed areas with a variety of BMPs. OD SEG 5: Bubble-Up Basin Detaining sediment-laden runoff. OD SEC 6: Blasting Controlling dust and erosion from blasting activities. OD SEC 7: Alteinative BMPs Goveming the use of BMPs not discussed in this report. OD SEC 8: Requiring staging within a sandbag-bermed area of Landscape Staging Area plants intended for landscaping to contain, in a localized area, sediment transported from piant watering. ESC 1: Scheduling Sequencing the project to reduce the amount and duration of soil exposed. ESC 2: Controlling emsion through preserving existing irees, Preservation of Existing Vegetation shrubs, and/or grasses. ESC 10: Seeding and Planting Stabilizing soil with vegetation including hydroseeding, trees, shrubs, sod, etc. ESC 11: Mulching Stabilizing soil with mulch, soil binders, and sealants. ESC 20: Geotextiles and Mats Stabilizing soils with erosion matting of natural and synthetic materials. ESC 21: Dust Controls Controiling fugitive dust through, primarily, watering and street sweeping. ESC 22: Providing for construction access over streams with Temporary Sheam Crossing culverts, fords, or bridges. ESC 23: Stabilizing vehicle routes through watering, berms, or Construction Road Stabilization paving. ESC 24: Stabilizing points of ingress and egress and points Stabilizing Construction Entrance where paved and unpaved roads meet. ESC 30: Earth Dike Managing runoff, desilting, or channeling water with earthen berms. ESC 31 _ Managing off-site run-on and on-site runoff through Temporary Drains and Swales stabilized channels. ESC 32: Slope Drain Draining slopes and channeling water with pipe drops, downdrains, or V-ditches: ESC 40: Outlet Protection Stabilizing drain outlets with rock and other velocity and erosion reducing devices. ESC 41: Check Dams Reducing the velocity of water with berms and sandbag dikes. ESC 42: Reducing runoff velocity and trapping sediment by Slope Roughening/Terracing creating microclimates and increasing infilVation and sedimentation. ESC 50: Silt Fence Detaining sediment-laden waterwith, primarily, fabric fencing or fencin combined with sandbags. ESC 51: Straw Bale Barriers Detaining sediment-laden water with straw bales. ESC 52: Sand Bag Barrier Detaining sediment-laden water and preventing hazardous material runoff with sandbag barriers. ESC 53: Brush or Rock Fiiter Reducing velocity of storm water and increasing sedimentation with vegetative or rock fiiters. ESC 54: Detaining sediment=laden water with straw and/or Storm Drain Inlet Protection sandbag barriers. ESC 55: Sediment Tra Providing sedimenta6on with excavated bermed areas. ESC 56: Sediment Basin Retaining and detainin sediment laden water. CA 40: Stressing the importance of employee training and Employee/Subcontractor Training requiring bilingual trainin when appropriate. ' OD = owner designed ESC = erosion 8~ sedimentation control CA = state required 3~` ' ' `, ' , ' ' t ' ' ' ) 1 ~ ' 1 ' ~ , ' } , OWN~R DESIGNED SEDIMENT & EROSION CONTROL BMP #1 SOURCE CONTROL Objective: To control sediment and erosion. BMP: Erosion control at the sediment sources will be emphasized during construction. 4 ~ ~ ~ ~ ~ ~ ' OWNER DESIGNED SEDIMENT & EROSION CONTROL BMP #2 ' SEDIMENT NIDVIMIZATION ~ Objective: To control sedimentation. ' BMP: The construction area shall be controlled to attenuate sediment from leaving the site or entering public or private streets. , r r r r ~- r r r r ~ r r . r r $ ~ i , ' ' OWNER DESIGNED SEDIMENT & EROSION CON7'1tOL BMP #3 ' RUN-ON , Objective: To reduce erosion and sedimenta6on by controlling and diverting off=site run-on ' which would otherwise contact disturbed construction areas. ~ BMP: Off-site run-on shall be diverted away from disturbed areas through the use of silt fencing, sandbags, construction of temporary drains and swa]es, construction of V-ditches, and other measures described in the Erosion Control Plan. For further ~ details on these individual measures, see fact sheets ESC 31, ESC 32, ESC 50, ~ and ESC 52. ~ I f, r ~ ~- i- r r ~- r~ I 6 ~~` , ' , , Objective: , , , , ' 1 ' ' ' ' 1 ' I , OWNER DESIGNED SEDIMENT & EROSION CONTROL BMP #4 DISTURBED AREAS To control erosion and sediment during the rainy season and the dry season through a combination of stabilizers, bamers, and settling devices. BMP: Areas of disturbed soil sha11 be stabilized, as appropriate, with mulches, erosion matting, soil stabilizers and binders, and/or vegetafion during the traditional Southem Califomia rainy season. Disturbed areas shall be secured during the rainy season through the use of barrier devices such as sand bags, dikes, berms, and bales; runoff from these azeas shall be channeled through settling and filtration devices such as silt fencing and sediment basins. During the traditional Southem Califomia dry season, the above measures will be employed to control sediment discharges at the downgrade perimeter and at operational inlets in the event of a predicted storm. ~~ , _ ~ t ' ' OWNER DESIGNED SEDIMENT AND EROSION CONTROL BMP #5 ' BUBBLE-UP BAS1N , Objective: To retain or detain runoff sufficienUy to allow passage through of acceptable ' volumes of storm water downstieam, thereby keeping storm water from eroding down stream areas. ' BMP: Genera] Description: A bubble-up basin is a controlled storm water release ~ structure created by excavation or construction of an embankrnent and is designed to rrunimize excessive discharge into the downstream storm drainage system. ~- Large stonn water flows enter the bubble-up basin through an inlet stiucture or overflow sUvcture. Once the downstream storm drain system has sufficient ; capacity to handle the storm water that has been retained in the bubble-up basin, the retained stbrm water enters the downstream storm drain through an outflow ~ pipe, eventually draining the bubble-up basin. Bubble-up basins can be 1 temporary or permanent siructures. ' Suitable Applications:. At the outlet of all developed watersheds in which the ; downstream storm drainage system is of insufficient capacity to handle the peak stonn water runoff. ' Installafion/Application: Requues Imowledge of storm drain flows, the water shed storm drainage system, as well as the downstream storm drainage system. ' The basin should be designed under the direction of a California registered engineer with a knowledge ofhydraulics. Do not locate a bubb]e-up basin in a , stream. AIl bubble-up basins should be located where failure of the embanlm~ent ~ would not cause loss of life or properiy damage. Large basins are subject to state , dam safety requirements. Small basins are subject to local agency requirements. ' ~ , ~ ~ ~ ~ R ~ ~ 3~ '- ~ ' - ' ' , , ' , ' ' ~ ' , ~ - ' , , , ' Requirements: Maintenance: Inspect after each rain event and as directed by the site monitoring section of the SWPPP. Remove debris at inleUoutlet structures and any sediment deposited in the basin. Cost: Construction costs can be high due to excavation and storm drain system (pipe instructure) requirements. The following graphic provides the general appearance of a bubble-up basin. OVERFLOW BASIN SLOPE VARIFS ` ~ INLET/OUTLET .-- -------`L --- -- -~-- ~,n3~~~ ~ ...__~~ ....__ ~_ ~ STORM DRA1N UNE ~- ~ L~~ 9 1 ' _ ? OWNER DESIGNED. SEDIMENT & EROSION CONTROL BMP #6 ' BLASTING Objective: To reduce dust generation from blasting ac6vities and to stabilize soil, reducing the potential for erosion after b]asting takes p]ace. ~ BMP: All blasting operations shall be conducted in compliance with the rules and regulations set by the most shingent government agency, usually the United ~ States Office of Surface Mining; the permit issued by the local fire deparhnent; and any contractual conditions set by the owner. Procedures such as watering ~ shall be employed, as warranted, to reduce dust emissions. Disturbed azeas of exposed so~l shall be stabilized as soon as possible. Stabilizing measures may ~ include compacting of ]oose soil; using soi] binders, mulches, and erosion matting; and securing the azea with diversion devices (e.g., silt fencing) and ~ detention controls (e.g., sandbag berms). . ) ' , 1 ' 1 1 i ~7 ; i o 4` ~ ' OWNER DES]GNED SEDIMENT & EROSION CONTROL BMP #7 I ALTERNATIVE BMPS A Objective: To ensure contractors do not implement altemative practices outside of the BMPs ~ described herein, unless those practices are incorporated into the SWPPP. BMP: Contractors shall not implement a BMP outside the scope of BMPs discussed in , this SWPPP until the new BMP is incorporated into the SWPPP. If a contractor ; proposes to take action that would constitute an alternative BMP not addressed in this SWPPP, the contractor will advise the owner of the proposal and must obtain ~ the owner's prior approval before implementing such BMP. The owner and/or the owner's representative will evaluate the proposal and determine if the ; proposed practice meets the BATBCT standard. If so, the owner will revise the SWPPP to incorporate the new or amended BMP. If the altemative practice does ~ not meet the BAT/BCT standard, its use will not be allowed. ' ' ' 1 ' ~ ~ ~y 11 ' ' , OWNER DESIGNED SEDIlVIENT & EROSION CON1'ROL BMP #8 t LANDSCAPE STAGING AREA ' Objective: To ensure that plants intended for landscaping are properly staged and contained , such that run-off from plant watering does not contribute sediment to the storm drain system. ' BMP: Store planting material, trees, and soi] amendment on dirt azeas whenever ~ possible. Control watering run-off so that it remains on dirt area. When storing plants on pavement, wherever possible, place trees and major mulch ' stockpiles at the high side of the site, away from gutter flowlines and catch basins. Altemately, bag perimeter of any tree stockpile areas 4o prevent urigation runoff ' from leaving stockpile area. Any access opening in the bagged perimeter should be on high side of the stockpile area only. Altemately, bag perimeter of major ~ j mulch, sand and suppiement stockpiles to prevent material run-off during storm ~ events. Access shouid be on high side only. ' ~ ~ ~ Ll ~ ^ ~ r ~2 A3 ' , ~ ~ ~ , ' ' ' ' ' ) ' , ~ , , ' ~ ~ / r BMP: SCHEDULING Objectives v a • Nnusekeeping Prac6ces • ~ S'y Contain Waste Minimize Disturbed Araas • ~ ~ .S,'1 p StebiJize Disturi~d Areas ~ ~ Gys ~ O Q~i ~ sA 1 ~ rotect Slopes/Channe s 1 Control Site Perimeter (~ 1g ontrol /ntema! Frosion DESCRIP'I'ION Targeted Pollutants Sequencing We conswction project w reduce tt~e amount and duratiou of soII ezposed w erosion by wind, rain, runoff, and vehicle lrxking. ~ Sedlment ~ Nutrients SUTTABLE APPLICATIONS . Q Toxic Materia/a Proper sequencing of construction activities w teduce erosion potential s6ould be incorpo- rated into the xhedule of every construction project. Use of otber, more costly yet less ~ Oi/ ~ Gresae effective, erosion and sedimentation controls; may often be reduced through proper ~ Fbateble Materiels conswction sequencing. ~ Othe~ Constructfon APPROACH Waste Project design coosiderations: Design projec[ to integrate into ezisting land contours. ~ Uke/yluHave Significan[ regrading of a site will require more costly emsion and sedimentation slynlNrant /mpaet convol measures and may require that on-site drainage facilities be installed. Q Probabre Low or Incorporate ezisting; nahual azeas: lnventory and evaluate the ezistin site terrain and Unknown lmpaet g vegetarion. Disaubance of highly erosive nanual azeas (e.g., steep, unstable slope ~mplementation areas, watercourses) s6ould be minimized, while praecting other areas may ea6ance Requirements site aesthetics. Consmiction sbould not distwb tLese areas (see ESC2). Avoid iainy periods: Schedule major grading operations during dry months. A]low ~ Capital Casta enoug6 time befote iainfall begins to stabilize t6e soil witL vegetadon or physical Q 06M Coats means (see ESC 10 to 24) or to install temporery sediment trapping devices (see FSC ~ M f t 50 to 56). e n enenca Practice erosion and sediment control year round: Erosion may be caused durin8 dry 0 Training seasons by "freak" tainfall, wind and vebide hacking. 'ILerefore, keep tLe site ~ Suitibility /or. stabilized yearround, and retain wet season sediment trapping. devices. Slopea >5~ • Minimize soil exposed at one time: Schedule projects to dispub only ssmall ponions of the site az any one time. Complete gading as soon az possible. Immediately stabilize tLe disnubed po~tion before gcading the next portion. Pracdce staged seeding-tevegetate ait and fill slopes az the wo~lc pmgresses. TrencLing: Closc and stabilize opeff trenc6esas soon as possible. Sequence treach- ~ y~yh ~ Low ing pmjects so that most o en oitions f th a h l d p p o e renc are c ose before new uenching is begun. ~ ~ ~ ~ REQUIREMENTS • Cost - Coastructioo scheduling to reduce erosion may increase other construction costs due tn reduced economies of scale in perfotming site grading. The cost-effec- tiveness of scheduling techniques should be compated with tbe otba, less BQSt effective erosion and sediu~enlation controls to achieve a cost-effective balance. Mana9e~pen Practices Construcdon HandUook 5 - 5 March, 1993 ~~ , ' ~ ' ' , , ' ' , ~ , ' '. - BMP: SCNEDULING{ Continue) LIMITATIONS . There are no significant limitations to the use of Wis BMP. REFERENCES Best Management Practices and Erosion Convol Manual for Construction Sites, Flood Control District of Maricopa Coimry. Arizona - 1992. Erosion and Sediment Control Guidelines for Developing Areas in Te~s, U.S. Deparunent of Agiculnue, Soil Conser- vation Service, Fort Wath, Te~cas - 1976. Stmm Water Management for Construction Acdvires. Developing Polluuon Prevenuon Plans and Best Management Practices, U.S. Environmental Protection Ageocy, OfFice of Water (EPA 832-R-92-005) - September, 1992. Viiginia Erosion and Secliment Controi Handbook, Third Edition, Virginia Departmen[ of Conservation and Recreation, Division of Soil and Water Conservation - 1992. , ' ~ ~ . ~ 1 I ESC~ II Construction Handbook 5-6 March~ 1993 ~ '' . ' ~ ~ ' ' ' ~ , ~ 1 , ~ ~ ~ ' r ~ r ~ '... BMP: PRESERVATION OF EXISTING VEGETATION objectives Housekeeping PracGces ` Contain Waste ~ inimize Disturbed Aieas tabifize Disfur6ed Are Protect Slopes/Channel Control Site Penmefer ~ '~°~~''i~'~ ' ~ - a Controllntetrtal Erosion ,~ ., tr - GENERAL DESCRIYTION Targeted Pollutants Carefully planned preservation of existing vegetauon minimizes the potential of removing ~ Sediment or injuring existing trees, vines, shrubs andlor grasses tha[ serve as erosion controls. ~ Nutrients SUTTABLE APPLICATIONS O Toxic Materials • Areas wilhin site where no consWC[ion activity occnrs, or occurs at a later date. ~ OilB Grease • Sensitive areas where namral vegetation ezist and should be preserved, such as: steep slopes, watercourses, and building sites in wooded areas. ~ Floatable Mate~ials Areas where local, state and fedeial government requires preservauon, such az: vernal ~ Other Consfruciion pools, wetlands, marshes, cettain oak trees, etc. Waste INSTALLATIONlAPPLICATION CRITERIA ~ Llkely to Have • Glearly mark, ilag or fence vegetation or azeas wLere vegeiation s6ould be preserved. slgnUlcanr tmpace Prepare landscaping plans which indude as much eusting vegetation as possible and ~ P+obebie Low or state pmper care of this e t ti b W d ri Unknown lmpact v ge a on o u ng and after conswction. Define and protect with berms, fencing, signs, etc., a setback area from vegetation ro ~ Implementation be preserved. Setback area size s6ould be based on the location, spedes, size, age and Requirements potential impact of adjacent construcuon activifles or permanent improvements. Proposed landsc~ping plans w6ich do notinclude plant species that compete witb the ~ Capita/ Costs e~cisting vegetation. Q O&M Costs Do not locate conswction traffic routes, spoil piles, etc., where significant adverse t ~ M i impact on existing vegetation may occur. a n enance 0 Training REQUIREME]V1'S ~ Suitability /or M~te~~ Slopes ~59: - Inspection and maintenance tequirements for protecfioo of vegetauon aze low. - During construc6on Ihe limits of gading or dishubance should be clearly mazked at all times. -' Irrigation or maintenai~ce of native Vees or vegetation should conform tn speciti- cations on We Landscape py~n, • Cost ~ High Q Lcw T7 i -. ~ere s little cost associa[ed with preserving exisdng vegetation if properly planned during the project design, and may yieid aestLetic benefits w6ich enhance l E S C Z pmperty va ues. LIMITATIONS • Requues forward planning by the owneddeveloper, contractor and design staff. For sites wi~h diversc topography, lt is often diffuul[ and ezpensive w save ezisting vees while grading the site satisfactorily for [he planned developmen~ BBSt Managemen Practices Consh-uction HandAook 5 ' ~ March, 1993 ~ ' t ' , ' , ' ' 1 ' ' ' Additional Information - Preservation of Existing Vegetation T6e best way to prevent excessive erosion is to not diswrb the land. On a consiruction site, where extensive land d'utnrbance is necessary, a reasonable BMP would be tn not disturb land in sensirive areas of the siie w6ic6 need not be altered for the project to be viable (e.g., natmal watermucses, steep slopes), and to design the site to incoiporate~particu- larly unique or desireable existing vegetation ~into the site landscaping plan. Clearly marking and leaving a buffer azea ~ amund these.unique azeas will both help to preserve these azeas as wel] as ~ake advantage of natural erosion prevenuon and sediment trapping in naturally vegetated ueas. Ezisting.vegetation to be preserved on ~he site must be protected from mechanical and other injury while ~he land is being developed. T'he pwpose of proiecting exisung vegetauon is to inswe the survival of desirable vegetauon for shade, beautifica6on, and erosion protecuon. Mature vegetation has extensive root systems that help to hold soil in place, Wus reducing erosion. Also, vegetation helps to keep soII from dryiug rapidly and becoming susceptible to erosion. To effectively save exisung vegetation, no disturbances of any kind should be allowed within a defined azea around the vegetaiion. For vees, no consvuction activity should occur witLin We drip line of [he vee. The following criteria may be used for deciding which vegetation will remain on ihe site: • Aesthetic values: Consideration s6ould be given to foliage, ilowering habils, bark and crown characteristics (tor vees). • Freedom from disease and ro4 • Life span of trees: Short-lived trees need not be preserved. • Envua~mental values: Habitat; screening; and bufiers. • Sudden exposure: Save vegetation which grows in d'uect sunligh[ and is able to witLstand radiated heat from proposed buildings and pavemen~ • Space needed: -Suf£icient space must be provided belween the vegetation and any strucmres, elecaic and telephone lines, water and sewer lines, driveways and streets. Mark lrees and slirubs.with bright pain[ or ribbon so there is no doubt as ro which trees and shrubs are to be left and protected from damage during conswction. Saving existing vegetation and mahue vees on-site, beautifies iLe area and atay save money by reducing ~w landscap- ing requiremeots. Mature trces also increase property values and satisfy consumer aesthetic needs. Preserving and protecting exisung vegetation can often result in more stable soil wnditions during conswction. Careful site planning and idenuFication of plandngs to preserve can provide erosion and sedimentauon convols during conswc- tion, and contribute m the aesthetics of the development For example, in Sacramento County a vee ordinance has been adopted tbat pro~ects the nauve Califomia Oak Vee. Provisions to protect the tree and its root system during conswction must be specified in the project plans, and an area must be provided where ihe soil stability may not be disuubed. No grading or conshuction storage within the tiee dripline is allowed. Installation/A~olica~ion ~ - _ . ~ . ~ Building sitrs may be planned to integrate eusting vegetation and Vees. Conswction impacts must be considered. Trench widW for pipe constiuction projects and the loca8on of permanent swcpues, such as buildings, needs to be considered when preserving ezisting vegetation, includiag mature trees and their root system. Native vegetation sLould be preserved since it is able to adapt a Wo climatc. The USDA Soii Conservation Service should be contacted about ezisting vegetation for sites throughout California Mature trees aze generally preferabie to newly planted trees because of t6e greater soil stabilization provided by tl~e eztensive root system of a mahue tiee. I ESC2 1 ~ r Construction Handbook 5-8 March~ 1993 ~~ ' ' ' ' 1 , ' t ' 1 ) , ' ' 1 ' ' " ' :} , /~dC~I~lOtla~ ~t1fOC1118t1Ot1 - Preservation of Existing Vegetation Methods for protecung exisung vegetaaon and vees: Stake off root system limi~s (drip Gne of tree). Some counties limit consWCGon within 5 feet of the tree drip 7ine. Fence o(f 1be area [o be preserved or along We trce drip line. - F7ag w mark trees to remain in place_ Tree wells and retaining walls (pem~anent) help preserve exisung vegetation, but must be lazge enough to protec[ the root system (see below). . For the Califomia Oak tree, no trenching or urigation s6ould be allowed wiUvn ~he driplines of ihe vee, since botl~ these activities are detrimental to the preservarion of the vee. Where grading under vees is nuessary, expvation and fill should be limited to 1 foot wirLin the dripGnes. REFERENCES Best Management Pracrices and Erosion Control Manua! for Conswction Sites, Flood Conwl Disirict of Mazicopa County, Arizona, September 1992. County of Sacramento Trce Preservation Ordinance - September 1981. Stormwater Management Water for tLe Puget Sound Bazin, Washington S~ate Deparm~ent of Ecology, The Technical Manual= Febn~ary 1992, Publicauon lf 91-75. Water Quality. Management Plan foi the I,ake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regional Planning Agency - November 1988. Construction Handbook 5-9 I ESC2 11 IvIarch, 1993 ~g ' ' ' , ' , ' , 1 ' ' , ' ' ' BMP: SEEDING AND PLANTING objectives Nousekeeping PrecSces Contain Waste r " ~ • ~~ ,.' Minimize Dfsturbed Areas f f ' - ~ ! ( / II ~ /V tabilize Disturtied Are rotect Sfopes/Channel ~ Contro! SNe Perimeter ~ ~ I ControllntemalErosion GENERAL DFSCRIPPION Targeted Pollutants Seeding of gratses aod plantings of trees, shrubs, vines and ground covets pcovide long- ~ Sediment [erm stabilitation of soil. In some amas, wit6 suitable climates, giasses can be planted for 0 N t i t temporary stabilization. u r en a Q Toxic Matertals . SUTTABLE APPLICATIONS. ~ OIl 3 Grease Appropriaze for site stabili7ation both during constcuction and pos[-construction. 0 FbatsbJe Materials Any graded/cleared areas where consvuction activities have ceased Open space cut and fill azeas. O Other Conatruction Stcep slopes. Wasie Spoil piles. V ~ Uk l to H egetated swaleS, e y svs ~ ~ Landscape.corridocs. S/ynlfleant/mpnct . S veam banks Q Probnbh Low ot . Unknown /mpact INSTALLATION/APPLICAITON CRITERIA implamantatlon Type of vegetation, site and seedbed pnparation, planting time, fertil'uation and water peyuirements requuement~ s6ould be consideicd for each application. Q Capka/Coais C'~bt~: ~ Q ~ 03M Costa Ground preparafion: fertilize and mechanically stabilize the soil. Q~+ntenance Tolerant of short-ferm temperdture eztremes and water]ogged soil conditions. • Appropriate soil conditions: shallow soII base, good drainage, slope 2:1 or flazter. 0 TrelnJng • Develop well and quickly from seeds. 0 Suitsbility for Mowing, irrigating, and teitilizing are vita! for promoting vigorous grass gowW. . . Sbpas ~Sx Trees and Shrubs: • Selection Criteria: viRor. species, siu. sbape ~ wildlife food source. • Soil conditions: select species appropriate for soil,dreinage & acidity. Ol6er Facto~: wind/eacposure, temperature ezvemes, and 'uxigadon needs. ~ Hfgh 0 Low Vices and Ground Covecs: • Ground preparation: lime aud fertilizer preparation. ~ c(~ "' O • Use proper secding ra[cs. . v v Appropriate soil condidons: draiaage, aadity, slopes. Generally avoid speciesrequiringinigaGon. 625t Managemen Practices Construction Handbook S- 10 March, 1993 ,? ~~ ' ' BMP: SEEDING AND PLANTING (Continue - i ) ' REQUIRIIvIENTs Maintenance ~ _ Shrubs and trees must be adequately watered and fertilized and if needed prnned: Grasses may need to be watered and mowed. Cosc Average annual cost for installation aud maintenance (2~year useful Iife, source: EPA, 1992) - Seeding: $300 per acre, appropriate for flat slopes and stable soils, ' ' - Seeding with Mulc6ing: $I,100 per aae, appropriaze for moderate to steep slopes and/or erosive soils. Trees, shrubs, vines, and gmund cover: Cost, applicability based on species used and ~e~rain features. ~ LIMTI'ATIONS ~ • Permanent and tempcxary vegetation may not be appropriate in dry periods wiffiout irrigarioa Fertiliur requiremen~s may 6ave po~ential to create storm water pollution if impcoperly applied, ' t t ' ) ' • ' , ' , _ J . ' , ~ } ' Construction Handbook 5-Il ~ ESC10 11 Marc6, 1993 °.~ ' ' ~ ' ' ~ r ' ~ ~ ~ ~ ~ r I~ Additional Information - s~,~~9 a~ P~~,;~9 --~~ Peimanent seeding of grasses, soddfng, and planting of vees, shrubs, vines and ground covers can provide loag-term stabili7auon of soil. Petmanen[ sceding and planting convibutes to long-tecro site aest6etics and 6elps reduce erosion by reducing tlie velocity of runoff, allowing infiltration to occur, filtering sediments, and by holding soil panicles in place. Seeding and planting s6ould be applied as soon as fmal grading is done to all graded and deared areas of tLe conswc- tion site w6ere plant cover is ultimuely desired For ezample, vegetation may be established along landscaped corridors and buffer zones w6ere Wey may act az Filter svips (see TC6 in Chaptei 5 of the Municipal Handbook). Additionally, vegetated swales, steep and/or rocky.slopes and srream banks can also serve as appropriate areas for seeding and plantings. Tnstallarinn/Anp icatiou rit ria . Appliqtion of appropriate vegefation must consider: the seedbed or plantbed, proper seawnai planting ti~~ water requuements fertilizer requirements and availability of the selec~ed vegetation within the project's region. Pemianent plantings during We construction stage of projects requ'ue careful coordination between the local agency inspectors, proJ~ ~8ets, constcuction manageis, and landscape convac[or. Protocols for coordinaeon and implementacion procedures regscding site access, cooswction staging, and shon- and long-term planting azeaz s6ould be developed prior ro tbe construccion bid process. W6ere possible, these praocois should be established by and remain the responsibiGry of tLe site owcer. Bxause of the many available types of plants and ground covers and becaose sire conditions and land ux vary so widely wi~hhin Califomia, a setof gene:al guidelines is included for installadonJapplica~iop of ga.cses, t~ and shrubs, vines and ground covecs. However, your local municipality, Soil Conservation Service, agricultural extendon, or other resources s6ould be consalted on appropriace species, planting requirements, and mainteoance need5 for yo~ ciimate and soils. Grasses Grasses; depending on the rype, provide short-term soil stabiliration during conswction or ran serve as long- term/ pemianent soil stabilization for disaubed areas. In gane~al, grasse~ p~~~~ ~ow maintenance to areas Wat have been cleared, graded and mechanically stabilized S 1 icm: Tbe selxuon of tbe grass type is detesmined by tLe climate, itrigation, mowmg Gequency, mainteoance effort and soil- bed oonditions. AIILough gasses prohde quick gecmination and rapid growrh, tbey also have a s6allow roa system and aze not as effective in stabilizin8 deeP soils~ whe-e vees, shrubs and deep rooted groimd covers may be mrne appropriate. Several gracses aze adaptab~e a the vazious California climares. The fgure az the end of these fact sheets s6vws appro- P~ 8~~ f~ ~eB~~ ~~ Califomia. Blue gass is well adapted Wroughouc Califomia ezcept for m the valley regions. 7Le blue gtass is found on dry. sandy soils that 6ave good d~ainage. Beimuda giacs, on the ot6a hand is well adapred in the vaRey iegion where soils are dry. coeTSe and Leavi~. Specific sad mi~c ~d/or varieties for each site should be provided by ao appioved/qualified plant materiaLs 3pecialisL Construction Aandbook - 5-12 E$C10 ~ e.a `~~ . ~ t~a~~..~. ~ooz 1 , /~ddItI011a~ ~I1fOCI71at1011- Seeding and Planting - ~i ' ~~~ The following steps should be followeA ro ensure established growth: 1_ Select Ihe proper grass for the site. . ~ ~ ~ ' 2. Prepare rhe seedbed; soi] should be fenilized and contain good topsoil or soil at leut a 2:1 or tlatter slope. 3. Broadcast the seedings in tLe late fall or early spring. In t6e la~e fall, seedings should be planted by mid- September _ to bave established grass by Ihe October rainy season. ' 4. Initial urigation will be required often for most grasses, with follow-up urigation and fertilization as needed. Mulching may be requued in dry climates or during drought years, ; Trees & Shrubs Selection: _ . . - Trees and stuubs, w6en properly selected, aze low maintenance piantings tha[ s~abilize adjacent soils, moderete tLe ' adjacent temperamres, fi][er air pollutants, and serve as a barrier to wind. Some desirable cbarac[eristics ro consider in selecting vees and shrubs include: vigor, species, age, size and shape, and use as a wildlife food source and habita~ ~ Trees and slvubs to be saved should be dearly marked so ihat no conswction activity will take place within iLe dripline of Ihe plant_ The sites for new plantings should be evaluated. Consider We prior use of the land: adverx soil condiuons such as poor drainage or acidity; exposure to wind; temperature extremes; location of utilities, paved areas, and security ; lighting and tratfic problems. Tran~plan in : 75me of Year - Late fatl through winter (November ro February) is the pteferred time for vansplanting in most of Calitomia ' ~ ' Prep.~trauon - Proper digging of a vee/stwb includes the conservation of as much of We root system as possible. Soil " ~ ad6ering to the roots should be damp when We tree is dug, and kept moist until ie-planung. Ti~e soil ball should be 12 inches in diameter for each inch of diameter of tbe Wnk. Site preparation - Refer w]andscape plans and specifications for site and soil preparation, and for ability to cooMinate , conswcuon srrategy with pecmanent vegetation. I Supponing ~Le wnk - Many newly planted treeslsluubs need artificial support ro preven[ excessive swaying. , Watecing - Soil aroimd the tree s6ould be tborouglily watered after tLe tree is set in place. WLen the soil becomes dry, lhe tree Should be watered detply, but not often, Mulching around Ihe base of the tree is helpfu! in preventing roots from ~ drying out Yines & Ground Covers ' Vi~ ~~d coveis, and low giowin8 P~~, ~~n.quicklY spread, come in manY types, colors, and gowt6 habits. Some aze suitable only as parc of a smalt maintained landscape area, while some can stabi]ize large areas with litde ~ maintenance. F7owers, which provide little long-tum erosion control may be planted to add color and vazietal appear- ances. ~ ~ ) ' Construction Handbook 5-13 i ESC10 I March, 1993 5y , ' ~ , ' ' ' ' 1 ' ' ' t , ' ' 1 Additionai Information - s~r~9 a~a P~~t~~9 Cauaon should be exercised in tLe non-native vegetation because of impacts tn narive vegetation on adjacent lands. For ezample, spe.cies t6at may be planted at the constniction site can quickly spread and compete with miginally undisturbed vegetadon sucb az tbe Califomia Poppy and Califomia buckwhea4 both of wLich complete poorly with invoduced gtasses (e.g., planting wild oats is illegat in Califocnia). In addition to stabilizing disturbed soIl,.vines and ground covers can perform the following functions: 1.. . Provide amactive eover that dces not need mowing. 2. Help ro define trat5c azeaz and control pedestrian movemen[. Site Aenaration: Ground covers are plants tha! naturally grow very close together, causing severe competition for space nutrients and water. SoII for gound covers should be well piepared. 'ILe entire area should be spaded, disced, or ro[otilled to a depth. of siz to eight inches. Two to Wree mches of organie material, such as good topsoil or peat, sLould be spread over tlie entire area. P1aRtiIIZ~ 'Ihe following steps will help ensare good plant growth 1. Make the plantings following tLe conwurs of the land. 2. Dig the holes ll3larger than tLe plant root ball. 3. Know what deptli to place the plaats. 4. Use good topsoil or soil mizuue with a la of organic maner. 5. Fll hole 1/3 ro 12 full, s6ake plants to setUe soIl among roots, then water. 6. I.eave saucer-s6aped depiession arqmd We plant to Lold water. 7. Water tLoroughly and iegularly. ~ . . 8. Space plants according W the type of plant and tLe extent of covering desired. IY13tCI131S~ . 'Ihere are many difleient species of vines and ground covers from which [o choose, but care must be taken ir: :heir selection. It is essendal to select planting materials suited to boW tLe intended use and specific site characteristics. The plants discussed in d~is handbook are those which are known to be adapied ro Califomia, and commonly available trom commercial nucse~ies. Additional inforn~ation can be obtained from local nuiserymen, landscape architecis, and exten- sion agents. An approved low water use plant list may be obtained from the State Department of Water Resources or the Soils Cooservation Service. $Pd111t~CIILS Maintenance General requicements include: ' ~ • Grass mamtenance should be minimal to none. Lrigaaon and regular fettilizing may be~equued fa some types of g~asses. Mowing is onlY. re9ui~ed in aieas wLere aes[hetics or fue Laiards are a concern • Young hces shoiiid re.ceive an inch of water exh week fa tLe 5rst two yeazs aBer planting. 1Le tree s6ould be watered dceply. but not more ofien Wan once per week. • Transplanted bees shonld be fectilized on an amual basis. ' ~Pa P+~mB. watering, and application of feRilizer is necessary to maintam healthy and vigorous shrubs. A heavy laya of mulch applied around t6e shrubs ieduces wetds and retains moisture. • Trim old growth as needed to improve the appearance of ground covers. Most coveis need ~ce-a-year u-imming to promote gr°wth' ESC10. Constructlon Handlwok 5•14 March, 1993 ~3 1 ' Additional Information - s~a~~9 a~d a~a~c;-,9 _ ~ t ~ I.imi a6one ~ . ' , - - - . Conshuction acuvities aze likely to injure or kill trees unless adequate protective measures are taken. Direct conlac[ ,-~ by equipment is We most obvious probiem, but damage is also caused by root-svess from~filling, ezcavation, or compactiug too ciose to trees. • Temporary seeding can only be viable when adequate time is available for plants rogrow and establish. - (()va fenilizin8 of plants may cause pollution of storm water runoff. - ' Irsigation source and supply may be limiting, REFERENCES , Best Management Practices and Fsosion ConVOI Manual for Consuuction Sites, Flood Control Disvict of Maricopa Co~mty, September 1992 , "Dcaft - Sedimentation and Erosion Control, M Invenrory of Cutrent Practices", U.S.E.P.A., April, 1990. Guides for Erosion and Sedimrnt Convols in Califomia, USDA Soils Conserva6on Service - January 1991. , Kiowa Engineering, Interim Erosion and Sedimentation Control for Consiruction Acavities, Urban Drainage and Flood Control Distric4 ~enver, Colorado. ' Manual of Standards of Erosion and Sedimen[ Control Measuees, Association of Bay Area Governments, Jvn 1981. Proposed Guidance Specifying Management Measutes for Sources of Nonpoint Pollution in Coastal Watess, Work ,- Group Working Paper, USEPA, April, 1992. ) S[ormwaterManagement Water for the Puget Sou~ Basin, Washingron State Department of Ecol - Manual - Febtuary 1992; Publication # 91-75. ~Y. '1be Technical ' Water Quality Management Plan for tLe Lake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regional Planning Agency - November 1988. ' , 1 ' ESC10 , ) ~ ~ ' Construction Handbook 5-]5 March, 1993 ' ' ' ' ' , ' ' ' ' , , . ' , , , ' ' ' BMP: MULCHING objectives Housekeeping Preetices ' J Contein Waste '' ' I ~ ~ ~ J Mlrnmrze Dlstur6ed Areas ' Mulching ' ' ~ stabi~izevisrurbedarea rotect Siopes/Channel Disturbed SOiI Control Site Perimeter ~ ' ' . , . , , Control intemal Erosion GENERAL DFSCRIP'PION Targeted Poilutants Mulching is used to temporarily and permanenfly stabilize cleazed or frestily seeded areas. ~~~~~~ Types of mulches indude organic materials, strew, wood c6ips, bark or ot6er wood fibers, Vi f 0 N decomposed granite, and gavel. u en a Q Toxic Meferials SUITABLE APPLICATIONS 0 Oi/ S Gresse •'Temporary stabIIization of freshly seeded and planted azeas. ~ 0 Fh t b/e M i / Temporary stabilization during peciods unsuitable for growing vegetafioa s e ater a s Temporary stabilization:of area5 Wat cannot be seeded a planted (e.g., insutfiaent ~ Other Consi~uctfon Weate rain, stecp slope). MWches such as gravel and decomposed soils may be used as post-construcdon • k BMPs. particularly io acid iegions. . s yr~j~nt lmpset . ~ . ~ ~ Pro6sbb Low or INSTAI.LATION/APPLICATION CRI'IERIA unknownlmpxt Mulc6 prevents erosion by protecting tLe soil surface and fostering growth of new seedings that do not stabilize by [hemselves. ~ Implementation May be used witL netbng [o supplemen[ soil stabil'ua6on. Requi~elnents • Apply to pianting azeas wLere slopes are 2:1 or grea[er. Q Capits! Casta • Biuders may be required for steep areas, or if wind and runoff is a problem. Q OdM Costa Type of mulch, binde~, and applicatlon rates s6ould be recommended by manufac- 0 Meintenanre ttaer/contractot. 0 Trefneng REQUIRIIt7EN'I'S ~ SuitebiUty /or Maintenance Sbpea>5`K - Must be inspected weekly and after taia for damage or deterio:ation. • CosC Average aunual cost for installatidn and mainteoance (3-4 month useful life, source: EPA. 1992) - Straw Mulch: 57.500 per aae. - Wood Fber Muk6: 53,500 pet aQe_ ~ Hl /r Q Low~ - Jute Neuing: S12,500 per acae. g L~'^~°NS ESC11 • Wood fiber mulches should be used only in azeas witb over 20 inches a~ual precipi- I3I100. _ • Organic mulches are not permanent erosion contro! measures. • Mulches tend [o lower the soil surface tempetature, and may delay geimina6on of some secds. B25t • Permanenc mulches tor arid regions should include gavel and decomposad soils. Managemen Practices Construction Handbook 5-~6 March, 1993 ,} ~ , ' ~ 1 ' , , ' , , ~ , ' , ~ ~ _ ' r~ r Additional information - M~~~n~~9 Mulching pro[octs [6e soil from rainfall impach inaeases infiltration; conserves moisture around trees, shrubs and seedings; prevents compacaon and cracking of soil; and aids plant gowth for seedings and plantings by 6olding the seeds. fertilizers and topsoil in place until growth occurs. Mulches include organic materials, straw, wood chips, bark or otLer wood fibers, decomposed grazrite and graveL A variety of neaings or mats of organic or non-organic materials and cLemical soil stabilization aze practices that may be used conjunctively ivitli mulching. Mulching may be applied to all giaded and cleaied areas of the conswction site: • Areas which have been petmanently seeded to assist in retaining moisture, and to hold seedings; • Areas which need temporary soil surface protectipn because sceding cannot occur due to the season: • Areas between trees, shrubs and certain ground covers; • Areas where cl~a[ic condi0ons tequire a soil moishae re~ention aid to avoid cracking of the soil ac~d associated compac5on; and require soII temperatuie moditicati~. Ins aLlLaeoritArm ica icm -rit .ria Only a set of genecal guidelines is included for application and installation of mulclting on disaubed lands because of tl~e various climates, soil conditioos and land uses in Califomia lnstallation bf mulch consists of fiunishing all macerials, prepazing t6e soil surface and applying the mulch to all soil surface areas designated on ttie project plans or establisLed by,ihe si[e engineer. . Or~ mulch materials, sucb as straw, wood chips, bark and wood fiber, have been found W be most eftective where re-vegetation will be provided by reseeding. T6e choice of mulch should bc based on tLe size of We area, site slopes, surface cooditions suc6 as hazdness and moisaue; weed growth and availability of mulch materials. . Wood Fber Mulc6es: Wood fiber mulches consist of specially prepared wood fiber processed to contain no growth germiaa[ion mhibiting factors. 'Ihe mulch s6ould be from virgin wood, and be manufacmred and processed so We fibers will remain in uniform suspension in water under agitation to form a Lomogenous slutry. The fiber lengihs should be as long as possible rn inaease the effectiveness for erosion control. Wood fiber mulching should na be used in areas of exvemely hot s~m~mer and late fall seasons because of fire danger. When used as a tackifier with straw mulch, wood fiber mulches aze good for steep stopes and severe climates. TLe Califomia Otfice of We Soils Conservation Service recommends a non-tozic mulch green dye be used to provide a visual aid in metering applications. Wood Chips and Bark G6ips: Wood and bazk chips are suitable for application in landscaped. areas tl~az will not be closely mowed. Woat chips do not require tacldng. but do req~rire nitrogen treatment (12 po~mdslton) to prevent nutrient defidency. Bark chips do not require addidpnai nitrogeo fertilizer. When t6e wood source is near the pmject site. wood and berlc ehips can be very mezpensive. Ca~ition must be used in amas af steep slopes, since both wood and bark chips tend to wash down slopes ezceeding 6 p~cenL Straw Mulc6: Straw mulc6 is a good s6ort-term pratecdon most commonly used with seeding. 'Ibe mulch should be from the cuneat seaton's crop. A lener of cettification from the supplier should be requiied W show that the straw was baled kss than 12 montha from the delivery date. Wheat a oat straw is recommended. Emulsitied Asp6a1~ pspLai~ 1g uxd to ~ ~ye mulch to ~he growd s~sface, preventing t6e mulch from blowing or washing off.'ILe type aM quantity o[ aspl~alt used shonld not msult in a stotm water pollutlon probkm. Binder: Binder should be free flowing, noncorrosive powder prpduced from naausl plant gum sucb as tLose marketed under M-Binder, M 145 Binder, or ,a,Z-TAC. Synthetic, spray-on matecials ace not recommend~d since th tend to create an ffipuvious surface, and may enter tLe stmmwater sewer system via discharge runoff. ESC11 Construction Handbook 5-17 March, 1993 ~~ , ' ~ ' ' , ' , , ' ' ' , , ' ~ ~ Additionai Information - M~~~n~~9 ~~narationc/!~? - hode nrl Fnyinment ~ - . Straw Mulch: Sbould be applied in an even, uniform manner, eitLer by hand or by mu]c6 blowing equipment Straw . mulches must be~. anchored to prevent the mule6 from being blown or washed off the si[e. Ane6oring is aclueved in two ways: • Crimping: The mulch is anchored by running a heavy disc with fla4 dull, senated, closely-spaced blades over the mulched soil. Effecrive crimping embeds the mulc6 about 2 inches into the soil witbbut completely covering iL TLe disc should be run once or twice across the soil_ About 21R tons of straw mulch per acre s6ould be applied if tbe mulch is anchored by crimping. • Tacking: AcLieved using a emulssed asphalt or binder eit6er independently or followed by ctimping. If tacked, suaw mulch may be applied at a rate of 1 3/4 ton per acre, and tacked witL emuisified asphalt at a Tate of 500 gallons Per aae.. Wood Fiber Mulch: Typically applied with a hydroseeder az a iate of about 1000 tn 1500 pounds peracre, or as a sluery consisting of az least 150 pounds of binder, 400 pounds of wood fiber mulcti, and 200 gallons of water per acre. Rem~imm .n c Maintenance: MulcLed azeas iequire frequent inspecuon for damage and deterioraaon. Requiremenis wi11 vary greatly based on the type of mulch used and the type of vegetation to be established. Vegetarive mulc6es are usually not ~°~~ w be Pe~mac~en4 but are eztended only as a 6ase for re-seeding or re-vegetation. Where a permanen[ anchor for vegetation is required, along stcep slopes or azeas of higher velocity flows, then a,geotextile mat or cet is cecommended (see ESC20). REFERENCES Best Management Practices and Erosion Control Manual for Consavction Sites, F7ood Control District of Maricopa County, September 1992 , Controlling Erosion of Construc[ion Sites, U.S. Department of Agriculture, Soil Conservation Service, Agricultu~e Information # 347. "Ihaft - Sedimentation and Erosion Control, An Inventory of Current Pracdces", U.S.E.P.A., April, 1990. "Environmental Giteria Manual", Ciry of Austiq Tezac. Guides for Erosion & Sediment Control in Califomia, USDA Soils Consavation Servia - Jaauazy 1991. Manual of Standards of Erosion and Sediment Control Measuras, Association of Bay Area Govemments, June 1981. . Ptoposed Guidance Specifying Management Measures fot Sources of Noapoiuc Pollufion in Coastal Watecs, Work Group Wori~ng Paper, USEPA, April, 1992. Soil Frosion by Water, U.S. Depanment of Agriculnne, Soil Conservation Distxict, Agricultuce Infmmadon Bulletin #513: ~immwazer lvianagement Wahx for tLe Puget Sound Basin. Washingron State Depuvnent of Ecology. TLe Txlmical Manual - Febtuary 1992, Publication # 91-75. Water Quality Management Plan for the Lake Tahce Region, Vol~e II, Handbook of Management Piactices, Ta6ce Regionat Planning Agency - November 1988. ESCi i Construction Handbook 5-18 March~ 1993 ~~ , '. _ , ' ' ' , ' ' , ' ) , , ' . ' ' , ~ ' ) ' BMP: GEOTEXTILES AND MATS Objectives Housekeeping PracGces MAT Confain Waste Minimize Distur6ed Neas Sfa6ilize Disturbed Area rotecf Sfopas/Channe! Contro! Site Parimetar Control lntemal Erosion GENERAL DESCRIPT'ION Targeted Pollutants Mattings made of napual or synthetic material which are used to temporarily or perma- ~ Sediment nently stabilize soii. Q Nutrients SUTfABLE APPLICATIONS 0 Toxic Materia/s Typically suited for poso-construction sitc stabilization, but may be used for temporary ~ Oil & Grease stabilirauon of highly erosive soils. ~ Fl t bl M t i l Channelsand streauis. oa a e a er a s Steep slopes. ~ Other Construction Waste INSTALLATION/APPLICATION CRTTERIA Mattings may be applied to disturbed soils and where exisung vegeta[ion has been ~ Likery ro Nave removed. The following organic matting materials provide temporary protution unu] slgnl0eant Impact ~ j7CfII18I1Ci1[ Vegef3(jOll iS CS[~I1517C~ M WI1CI1 SC850713~ G77CUQI5f811CCS dICI2IC fI1C IICP.d I07 O~obabls Low or Unknown lm aet tem orar stabiliz ti ril b p p y a on un weat er or construction delays aze resolved. Jute mactings. Implemeniation Straw mattings. Requirements The following synthetic mattiogs may be used for either temporary or pos[-conswcuon ~ Capita! Costs stabili7auon, both with and without vegetation Q 0&M Costs Faccelsior matting, Q M i t Glass 5ber uiatting. a n enance • Staples. ~ Traininy Mulch nettings. ~ Suitebility for S/opes>5~ REQUIREMENTS Maintenance - Inspect monthly and after significant rainfalL - Re-anchor loosened matting and replace missing matting and staples as required. Cost - Relatively 6ig6 compazed to other BMPs. - ~ Hfgh 0 Low LIMTTATIONS C ~+^no Mattings are more cosUy ihan ot6er BMP prectices, limi6ng t6ea use to areu where G~7 ~~ L h BMP ot er s are ineffecpve (e.g., channels, steep slopes). • May delay seed germinali~, due to reduction in soil temperahue. Installation requires experienced contractnr to ensure soil stabilization and erosion prorecdon. Best Managemen Practices Construction Handbook 5•19 March, 1993 , ' ' 1 ~ 1 ' t ' ' ' ' ' QddIt10118~ ~I1fOC1118t1011 - Geote~iles and Mats Mattings are used to reduce erosion from rainfall impac4 hold soil in place, and absorb and hold moismre near the soil surface. Addiuonally, mattings may be used to stabilize soils uncil vegetauon is established. This pracpce may be used alone or with a mulch during the establishment of protecUve cover on criucal slopes (see ESCI 1, Mulching). S ~i abl Anolica ionc . _ Mattings aze commonly applied on s6ort, steep slopes whecc erosion bazard is high and vegetation wIll be slow to establish. Mattings are also used on stream banks where moving water at velociuu between 3 fps and 6 fps is'likely ro was6 out new vegetauon, and in azeas where tf~e soil sudace is disturbed and where existing vege~auon has been re- moved Matting may aLso be used when seec3-.' ig cannot occur (e.g., late season conswction and/or ibe arrival of an eaily rain season). Erosion control mauing s6ould be considered when ihe soiis are fine grained and potentially erosive. The following natural or syntheuc atattings aze commonly used: 7yICS13( - should be clotL of a uniform plain weave of undyed and unbleac6ed single jute yam, 48" in width, and weighing an average of 1.2 pounds per linear yard of doth with a tolerance of p4us or minus Cive (5) percent, with approzimately 78 warp ends per width of cloth and 41 weft ends per linear yard of cloth. 'Ibe yarn should be of a]oosely twisted consvuction having an average twist of not less than 1.6 tums per inch and shall not vary in tbiGrness by more than its normai diameter. Str.+w Mat - s6ould be a machine prod~ced mat consisting of 70%a (~%) agriculmral straw and 30'% (±3%) coconut fiber. Tbe blanket s6ould be of consistent thiclrness with the svaw and coconu[ fiber evenly disuibuted over We enlire area of ihe mat. 7Le blanket s6ould be rnvered on ttie top side wiU~ polypropylene netting having an approxima[e 5/8" z 5/8" mesh coataining ultraviolet addiuves to resist breakdown, and on the bonom wiW a polypropylene netting with an approximate " z" mesh. The blanket s6ould be sewn together with cotton iluead. Fxcel~i~r M~t - should be wood ezcelsior, 48 inches in width plus or minus one inch and weighing 0.8 pound per square yazd plus or minus ten percent T'he excelsior ma[erial s6ould be covered with a oetting to facilitate handling and to increase svengib. ~I ec Fiber Mat in„Q - should be of bonded textile glass fibers wi~h an average fiber diameter of eight to twelve microns, two to four inch strands of f ber bonded with p6enol formaldehyde resia Mat sbould be roll type, water permeahle, minimum tbiclrness inch, maximum thicFa~ess incb, density not less tl~an three pounds per cubie foo~ S an1 .e for anchoring soil stabilizing materials shouid be Number 11 gauge wire or heavier. TLeir length should be six to ten inc6es, with longer staples used in loose, unstable soIls. n h.r M,t h N.~ +~ - such as peper, plastic, cotton or fiber glass matting s6ould be installed according tn the manufacturer's recommendations. lnstalladon/A~rtlication Criteria Organic matting mate:ials Lave been found to be effective where re-vegetation will be provided by re-seeding. TLe choice of maz6ng sbould be based on.ttie size of azea, side slopes, surface conditions such as hardness azid moiswre; we growth and availability of mateiials. Matting slrengWs and uses vary, therefore, manufacWrer's specifirafions must be followed. Proper ins~allation of mattings is eciucal in order to obtain fvm; continuous rnntact with t6e soil. 1 ESC20 1 Construction Handbook 5•20 March, 1993 ~` ' ' ~ ' ' , ' t ~~ ~ ~ r l~ ~ ~ ~ ~ ^ ) ~ Additional Information - ceote~~ies a~d rnacs Sile Preparation: After )be site has been shaped and graded tD ihe approved design, prepaze a friable seed bed rela- tivety free from clods and rocks more tban 1 inches in diameter and any foreign maierial that will prevenl contac[ of [he protective mat wiih the soil surface. - ~ - Planting: Fertilize and seed in accordance wiW seeding specifications or oU~er types of landscaping plans. W6en using jute matting on a seeded area, apply approximately half the seed.before laying iLe mat and the remainder aRer laying the mat. 7'he protecuve matting can be taid over areaz where grass hu been planted and the seedlings have emerged. Where vines or other ground covers are to be plante4 iay ihe protec6ve matung Fust and then plant through matting according to design of planting. Erosion Stops: Erosion stops are made of glus Fiber sUips, excelsior matting svips or 6ghbfolded jute matting blanket or strips for use on steep, highly erodible watercourses. TLe stops are placed in nacrow venches six to twelve inches dcep across the channel and left flusti with ihe soil surface. T6ey are W cover the full ccoss section of designed Ilow. Laying and Securing Matting: BeCore laying tl~e mauing, a11 erosion stops should be installed and the friable seed bed made free fran clods, rocks, and root~. The surface upon which t6e separation fabric will be placed shouid be compacted and finished acco~ing to We requirements of ~e manufacturer's recommendations. Most matting comes wi~ the manufacturer's recommendations (ot installauon. Most channels will requ'ue muluple widths of matting, and ~he matting should be unrolled starting at tLe upper end of the channel, allowing a Cour inc6 bverlap of mattings along We cen~er of the channel. To secure,. bury [he top ends of the matting in a narrow uench, a minimum of six inches deep. BackfilI trench and tamp fumly to conform to channel cross secuoa Secure with a row of staples about fois inches down slope from the trencb with staples twelve inches apart Where matung ~crosses erosion stops, reinforce with a double row of staptes at six inch spacing, using a staggeied pa[tem on either side of Ibe erosion stop. W6en ihe matting is overlapped, the disc6arge end of the maning liner should be similarly secured with a double mw of staples. Mechanical or manual laydown equipment s6ould be qpable of handling fu11 rolls of fabric, and laying We Ixbric smootbly, without wrinkles or folds, The equipment should meet the fabric manufacmiei's recommendations or equiva- lent standards. Final Check: Check the following after We mating is installed: • Make sure maztlng is uniformly in contact with the soil. • All lap joints ace senrce. • All staples are flush with We ground • All disturbed areas seeded Limitations ~P~~Y ~5~~ n!attings provide excellent emsion control but do so az relatively high crosL 7t~is hig6 cost typically limits the use of manings to areas of concentrated channel flow and steep slopes. Installadon is critica] and requires ezperienced conuactors, TLe rnntractor should install the matting mateiial in such a manner that continuous contact between the material and the soil occurs, otLenvise We material will not stabilize t6e soil and eros~on wi11 occur beneath the material. Ultraviolet protection may be required on some geoteztiles. Mazting strengtbs and uses vaty; tbe manufacturer's spec~cabons should be followed Construction AandbooR 5-21 I ESC2o 1 March, 1993 ~0 ' , ' ' , ' ' ' ' ' ' ' ' ' ' ' ' ' ' QddItI011a~ ~I1fOC1118t1011 - Geotextiles and Mats REFERENCES Best Management Pracuces and Erosion Control Manual for Conswcuon Sites, Flood Control District of Maricopa County, September 1992.. -Guides for Erosion and Sed'unen[ Convots in Catffomia, USDA Soils Conservation Service - January (991. StormwaterManagemen[ Water for t6e Puget Sound.Basin, Washington State Department of Ecology, 7'he Technical Manual - February 1992, Publication #! 91-75. Water Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Pracuces, Tahce Regionai Planning Agency - November 1988. ESC20 µ~ A~ctMs Construction Handbook 5- 22 March, 7993 `~. ~4` 1 ' - l 1. ' ,. . ' ' ' ' ' ~ ' ' ' ' , ' Additional Information - Geotextiles and Mats 14 in ANCHORING ENDS AT STRUGT R Se PLACE THE END OF THE NET IN A 12" SLOT ON THE UP-CHANNEL SIDE OF THE STRUCTURE. fILL THE TRENCH AND TAMP FIRMLY. ROLL THE NET UP THE CHANNEL PLACE STAPLES AT 12" INTERVALS ALONG THE ANCNOR END OF THE NET. I ESC20 11 ' ~ 1 Construction Handbook ANCHOR SLOT: BURY 7HE UP-CHANNEL END OF THE NET IN A 12" DEEP TRENCH. TAMP THE SOI~ FIRMLY. STAPLE AT IZ"INTERVALS ACROSS THE NET. OVERLAP: OVERLAP EDGES OF THE STRIPS AT LEAST 4". STAPLE EVERY 12" DOWN THE CENTER OF THE STRIP. JOINING STRIPS: INSERT THE NEW ROLL OR NET IN A TRENCH, AS WITH THE ANCHOR SLOT. OVERLAP THE UP-CHANNEL END OF THE PREVIOUS RO~L 18" AND TURN THE END OF THE PREVIOUS ROLC.. JUST BELOW THE ANCHOR SLOT, LEAVING 6" OVERLAP. H K OT : ON ERODIBLE SOILS OR STEEP SLOPES,CHECK SLOTS SHOULD BE MA~E EVERY 15 FEET. INSERT A FOLD OF THE NET INTO A 6" TRENCH AND TRAMP FIRMLY. STAPLE AT 12" INTERVALS ACROSS THE NET. LAY THE NET SMOOTHLY ON .THE SURFXICE OF THE SOIL - DO NOT STRETCH THE NET, AND 00 NOT ALLOW WRINK~ES. 5.23 March, 1993 ~o~' 1 ' ~ , ' , ' ' , ' ' ' ' ' ' ' , Addifional [nformation - c~ce~~ies ana Ma~: ON SHA~LOW SLOPES. 57RPS OF NE7TING MAY BE APPIIED ACROSS THE SLOPE. ~I!-.`AILOW SL_~ P=^ ~ ~!~ ~~L~~~~~ ~ ' i ~ -y1J-~ _ : y""7 ~ ~~?~~~i S TI N ON STEEP SLOPES: APPLY STRPS OF NETTIN(3 PARALLEI TO~,TFIE DIRECTIDN OF FLOW AND ANCHOR .. . SECURELY. ~ STefP SCOPe I I SECTION E iSHA~LOW SLOPE51 PLAN M.017HCHES. APPLY NETTING PARALLEL TO THE UIRECTION OF F~OW. USE CHECK SLOTS EVERY 15 FEET. DO NOT JOW STR~S W THE CENTER OF THE DITCH. N N ANCHOR 7RENCH ~ I SECTION PLAN lSTEEP SLOP~ AN BRM6 NETTINO ~OWN TO A LEVEL BEFORE TERMMATING THE INSTALLATIOIJ_ TURN TFE END UNDER 6' AND STAPLE AT 12' MiERYALS. WF~RE THERE IS A BERM AT THE TOP OF THE SLOPE. BRMO THE MATTINO OVER T!E ~ BERM AND ANCHOR R BEHIND THE BERM IfIT}i A 12' ANCHOR TRENCH. ~ I ESC20 I Construction Handlwok 5-1A Macch, 1993 t } ) ~3 . ~ '1 ' . ~ t BMP: DUSTCONTROLS objectives Nousekeeping Practices Contain Waste 0 - inimim Disturbed Areas ~ Stebilize Disturbed Areas ~ ~ ~ O Protect SlopesJChannefs ontro/ Site Perimete Control lntemal Erosion GENERAL DESCRIP'TION Targeted Pollutants Dust cootrol meazures are used to siabilize soil trom wind erosion, and teduce dust gene:ated by construction xdvities. ~ Sediment - SiJTfABLE APPLICAT'IONS Q Nufrientt • Clearing and grnding aclivities, Q 7oxic Materra/s • Construction vehicle trafFic on unpaved roadt. 0 Oil & Grease Ihilling and blasting activities. ~ Fbatable Materia/s Sediment ttacking onro paved roads. ~ Other Construction Soil and debris storage piles. Weste • Ba[ch drop from front end loadecs. / ~ Uk t H Amas with uOStabili2ed Soil. m e y o avs. S/ynlftnnt /mpsct Foa( grdding/site stabilization usually is sufficient to controi post-constructioo dus[ Q P.obabb Low or ~SOtlICCS. Unknown/mpact IIVST L A LATION/APPLICATION CRITERIA • _ Schedule mnswction acfivities ro minimize exposed azea (See ESC I). ~mplementation Quickly stabilize exposed soils nsing vegetation, mulching, spray-on ad6esives, Requirements calci~ chloride, sprinkling, ar~d stone/gave] layering (See FSC 10 and 11). ~ Capital Coata Identify and stabilizc key access points priot to commeacement of construcfion (Sce Q 06M Coata ESC 24). . • Minimizing the impact of dust by anfiapating the direction of prevailing winds. Q Meintenance • Dicect most cons Wction UafYic to stabilized roadwa withm the YS P+olect site (See ESC ~ Treining ~~ Q Suitabiliry /or ~ - - . Sbpea>5'X REQIJIRIII~T1'I'$ Maintwance ' - - Most dust conorol measures req~iiie frequen4 oRcn daily, attention. • Cost - Installation oosts fa wazer/c6emical dust suppression are low, but annual costs ~ High O Low may be quite Ligh since these measutes are eff aiv f l f h e e or on y a ew ours w a few ~ys ~ ESC21 LIMITATIONS • Watering prevents dust only for a s6ort period and should be applied daily (or more . oRen) to be effe~ve. • Ovecwatering may puse erosioo. Oil should not be used for dust control because the oil may migrate into drainageway Best andlor seep into the soiL Managemen Catain chemically-treated subgredes may make soil water repe11an4 increasing nmoff. Practices Construction Handbook 5 - 25 March, 1993 ~a~ ' ' ~ ' , ' ' ' ' t ' , ~ , ~ ' ~ r Additional Information - ~ust controis Califomia's mediterranean climate, with short we[ seasons and long ho[ dry seasons, allow the soils to thoroughly dry oul Diuing these dry seasons, conswcvon activities are u Iheir peak, and disuubance and ezposed areas are inaeas= ingly subject to wind erosion, sediment tracking and dust generated by consWCtion equipmen~ Dust control, as a BMP, is a practice Wat is already in place for many consuuctioo activides. Los Angeles, the Nonh Coast and Sacramento, among oWers have enacted dust wntrol wdinances for conshuction activities that cauu dus[ to be vansported beyond the conswction p~oject property line. Ruendy, ~he Statc Air Resources Control Boazd has, under We auWority of the Clean Air Act, srarted to address air quality in relation to in6alable particulate matter less than 10 microns (PM-]0). 90% o( t6ese small particles aze consideted ro be dus~ Ezis6ng diut control regulations by locat agencies, municipal departmenfs, public works departmen4 ~~or pubGchealth departments are in place in some regions within Califomia. For jurisdic6ons Wat Lave no formal dust conlrol regulations and/or standards, Sections 10, 17 and 18 of CalT~ans' Standard Specitications provide detailed provisions for dust convol pracuces. Many ]ocal agencies iequite dust control in order to comply with local nuisance laws, opacity ]aws (visibility impair- ment) and tbe myuirements of the Clean Air Act. TLe following aze meazuces Wat local agencies may have already implemented as requiremenu for dust control from coutractnrs: • C'oas ,ctirm Cnadinp Permi ~; Require provisions for dust control plans; • Q~ ritv Fmiseion i.imi ~; Enforce compliance with Califomia airpollution conVOl laws; .. rncrease overalt enfcm~ement ~ ivities• Primity given w cases involving citizen complaints; • Maintain Feld pplication Recordc: Require records of dust control measures fmm contractbr, • Stocmwarrr Potl i icm v ntion Plam (SWPPP): Integrate dus[ contro( measures into SWPPP. Dast .ontrol Pra i s Dust cwitrol BMP's generally stabilize exposed surfaces and minim'vc activities that suspend or track dust particles. Table ESC21.1 shows whicL Dust Control BMPs apply to site conditions which cause dust For heavily tcaveled and disturbed areas, wet suppression (wa[ering), chemical dust suppression, gavel or asphal[ surfacing, temporary gravel construction entrances, equipmeot wasb-out areas, and haul truck covers can be employed as dust control applications. Pera~u~ent or temporary vegetation and mulc6ing and sand fences can be employed for areas oF occasional or no wn- strvction tra[fic. Preventive measures would include min;m;~;ng Surt'ace areas a be disqIIbed, liuti[mg on-site vehicle traf5c to 15 miles per hour, and controlling We number aod activity of vehicles on a site az any given time. Many of tLe reasonably available control measures for controlling dus[ &om consuuction sites can also be implemented as BMPs for stam water pollution prevention. 'ILose BMPs include: • Pave, vegetate, or c6emically stabilize access pomts where ~mpaved tiaffic surfaces adjoin paved roads. • Provide covers for haul wdcs transporting marerials that contribute to dusL • Provide for wet suppression or chemicai stabil'vadon of exposed soils. • Provide for rapid clean-op of sedimrnts deposited on paved roads. Fumish stabilized construction ro~ enitances . and vehicle wash down areas. • Stabilize unpaved haul roads, parking and staging areas. Reduce speed and trips on wpaved mads. • Implement dust control measures fa material stockpiles. • Prevent drainage of sediment Jaden storm wata onto paved surfxes. • Stabllize abandooed constcuction sites using vegetation or c6emical stabilization methods. • Limit the amoont of aeeas distucfied by cleaeing aud earth moving oper-dtions by sc6eduling these activifies in pLases. F°t t6e chemlcat smbilizat~on. t6ere are many pmducts available fa ebemically stabilizing gravel ro~ways and stoclc- piles. 'ILe types of chemicaLs available and recomm~dations for tLe'u use are tabalated 'w Table ESC 21.2, Commonly Used Chemicals for Dust Control. I Esc2t I Construction HandUook 5.26 March, 1993 6~ ' ' ~ ~ Additional Information - ~ust con~ois In addition, iherc are many otLer BMPs identified in this handbook that pmvide dust control including: • Seeding and Placitings (ESC 10) Mulcbing (ESC 11) • Construction Road Stabil'uatiou (ESC 23) • Stabilized Construcuon Eutrances (ESC 24) ' ' ' i ' , , ~ I.+mifatinnc . - ~ • Oil trea[ed subgrades stiould not bc used because t6e oil may migrate into drainageways and/or seep intn the soil. • CLemically treated subgrades may make the soII water repellant, interfering with long-term infiltration, and the vegetaaon/re-vegeration of tLe site. Some chemical dust suppressants may be subject to freering and may contain solvents and should be handled properly. . • Asphalt, as a mulcb tack or cLemical mulc6, requues a 24 hour curing time to avoid ad6eience to equipmen4 worker shoes. e[c. Application sbould be limited bepuse asphalt surfacing may eventually migate into the diainage system. ~ In compacted aceas, wuering and other liquid dust control measures may wash sediment or other constituents into the drainage system. REFERENCES Best Management Pr~ctices and Erosion Control Manual for Construction Sites, Flood Control Disaict of Maricopa Co~mty. Arizona, September 1992. Califoroia Air Pollution Control Laws, Califomia Air Resources Boazd, 1992. CaiTrans, Standard Specifications, Sections 10, "Dust Conwl^; Secuou 17, "Warering"; and Section 18, "Dust Pallia- tive". Prospects for Attau~ing tbe State Ambien[ Air Qualiry Standards for Stupended Particulate Mattet (PM 10), Visibility Reduang Particles, Sulfates, Lead, and Hydrogen Sulfide, CaL'fomia Air Resources Boazd, April 1991. Sacramento County, Winterization Ordinance & Dust Contml Ordinance (ezamplej. USDA Soil Conservafion Service, "Guides fa Fmsion and Sediment Control": 1 ESC21 i r~ r Construction Handbook 5-27 Mazch; 1993 ~ ' ' ' ' ' , ' ' , 11 ~ ' ' ' ' z 0 E~ °z O U W F ~ Z W ~ U C~. ~ w a ~ q a 0 ~ E• z ~ U F ~ ~ a ~ ~ N U ~ w w a q Q.' F ~ R f - e =~Q = x x x x x ~ C ` L ^ ~ 1 ~ tr~ xE-~ X X > esaF V V ~ z e ~r X x ~~ e 3 F W a ~ L L A - N ~+ X C J O s ° `° z ° U - .~ n v >at x x x x vFi V a ~n ~ O a = __~ ~ Li 6 x x x x x G j Vi O ~ 3a; x x x x x x ~3 ~ -- ~ ~ ~ x ~ ~ e cs ° ° SC c~ a`> .Z C U .~ 4:. U -v~ ~: ~ G. . ~ N ~ O o~ ~ ~ o ¢yF ~F ~ ^ ~ i= o p . Z y ~ s ~ O ` C ~ K [I' ~.j yi U ~ U ~ U ~ ~ ~ ~ ~ C n ~ c F~ u `~ ~ ?; .o 3 L] v'~ A v'~ ,~ v~i q U F~ ~ r Cotutruction Handbook 5 - 28 March, 1993 ~~ ' , ' ) ' ' , ' , ' ' ' ~ ' ' , , , , , , ,~ J O a z 0 U E"~ ~ C a W a U W rZ U G ~ a ~ a z O G ~ U N N U h W W J q F n ~ ~I.1 W ~ T L ~ ~ ~ . ~ ~ 7 ;J C ~ 'J vi N - I ~ ^ C C ~ (b C N ,~ c3 0 - ~~ cQ '~~ 3 ~b~° ° c W ~ ~ O. - .p p~ c~ ' ,<~ ° ~ v 3 n - ~ ~` ~ , , ~ . V c~n c s L C1. aJ a i/J ~. C ~ j y •- - ci •- ~ ~. . ~ ~3 . cJ ~, a mQw n, • o y c C :J rj - y N 'O ?~ `~ . • • p C7 O C. 0] ~ - (~ . ~ A ~ C ~ d C N C cUV U 61 .. .. ~~ ~ ~"" ~ - ~ C> Z V] O¢ C .° c o cJ V 3 j'~ cJ o cn ~ y~°° c Z G~ , N CA ~` ?~ ~ O ~' y W N'n O 4: U~ vi . C' ~ _1 i t 'J T h~ a~ w~ v~i n a a> .~ ¢ ~ ~ ~ j :~ ~- ~ ~ ~' V ~ ~ ~ p „ ~ C ~ c ~ e vo ~ o ~ ° L >' ~LC ~ oN~~ ~ a a O F~ ~ ' E U ~ c ~° ~~ ° "' m c 3 3 - ~ v ~ ~ 3 o a i ' 3 U~ ~ ~ ~. . ~, r., ~ 0. U in Q ci a~ ~ : y~ ' ~ c~ ~ a i ~'y- ~ ~ C1 ~ c u . C + o c o"- O a+ a o a~ 3 0. '"' ' c . . Z ~~ ~ m ~.. ~ ~ ~ ~, h ° ~ T cy ~~ o ~ T V . h ~ ~O 7 ~. 7 ~ C .. C9 O .( ~-+ N G y ~o' .- ~"' 4'. oo ,C n. 3 UT y ~ ~n C C o a L',' aL CL~ ~"'4.. N ~ "r ~ .~ V] o U ai L > 3 o ~ ~ e Oi 3° ~ ' D 3 3 + =,y U N p ~ y .~O ~y V ~ ~.i". 'J O C~~ L Ca„ cVa o c ~ °' '3 •`; E 3~ a[i ."".. U T .~ ~ ~ o ~ ~. ~ G ~ ~ N n V~ Z ~ " o =i `' m o =°~ c ~ 'C q 4' V U ~ > ' ' • ~ U a.] z `y~' ~ ~ a> :° U .o on ~ W GL ~ + F ~ z ~ ~ ~, F V z w F ~ ~ U o ..7 V y 3 ~ O ~ ~ c ~ ~ o. c O ~ ~ d ~ ~ > ~ O J . ' ~ ~ N ^ N ~ ~ c. c OU' ~ ` ~ ~ o ~ e d ~ ~ ~ ~ v' m a ~ u 5 ~ "0 9 m ~ ~ ~g o 0 V 0 ~ z ' ConsUvction Handbook , 5- 29 Mazch, 1993 ~/$ 1 ' , ' , ' ' 1 ' , t . , ' ' BMP: TEMPORARYSTREAMCROSSING objectives I ~ ~ .. . Housekeeping PracUce '~% ~" ~, ~- ContainWaste ,.. ~, ~ ~ i u• .• ~ ' ~ Y . v ~.~::... • ~1 - v - inimize DisturbedArea ~ ~~. .s'e •.:..::':' ~\ •'-'~; ~ ~•'" • •.`t abilize Disturbed Are ~ • ~ ~:;..: ~~~.,,. ti, ,4, ~'•. ~` ~~ ~, " ' rofectSlopes/Channe ~ ,\ ;~~~ ~ ~ ~i ~/ , ti Control Site Perimeter ~~ d ~ v 1 ~ ~ Confrollnternal Erosion GENERAL DESCRIPTION Targeted Pollutants A temporary access sVeam crossing is a temporary culvert, ford or bridge placed aaoss a ~ Sediment waterway to provide access for conswction purposes for a period of less than one year. ~ N t i Temporary access crossings aze not intended w be used to mau~tain traffic for the general u r ents pubGc. ~ Toxic Materials Q Oil & Grease SUTTABLE APPLICATIONS Q FJoatable Materials Temporary stream crossings should be installed at all designated crossings of perennial and intermittent sueams ou We conswction site, as well as for dry channels which may be O Other Cvnstruction signiticantJy eroded by consvuction vaffic. Wasie INSTALLATION/APPLICATION CRI'PERIA ~ ukery rv Have Requues knowledge of stream flows and soil strengt6 and should be designed under the Stynircant impact direction of a California re istered en meer wi~h Imowled e of both h draulics and g g h B Y i ~ Probabie Low or Unknown lmpact conswct on ]oading requirements for swcdues. Implementation REQUIREMENTS Requirements Maintenance - Inspect weekly and after each signi6cant rainfall, including assessment of Q Capita! Casts foundauons. . Q 08M Cnsts - Periodically remove silt trom capssings. Q Maintenance - Replace lbst aggregate fmm inlets and outlets of culverts. • Cost ~ Treining - CalTrans Construcuon Cost IrMex for temporary bridge crossing is S45-S95 per ~ Suitabiflty lor square feet Slopes>55: LIMITATIONS • May be an expensive for a tempordry improvement • Requires other BMPs to urinimize soi- disturbance during installation and removal. • Fords stwuld only be used in dry weather. ~ High ~ Low ~ ESC22 Best Managemen Practices Construcdon Handbook 5-36 March, 1993 1 ,~ ~vQ ' ' ~ , ' , , , ' , ' ~ , , , , ~ ~ ~ J ' I~ Additional Information - Temporary Stream Crossing II /1 temporary access stieam aossing is a culvert, ford, or bridge placed across a waterway w provide access (or conswc- uon for a period of less U~an one year. Temporary access crossings are not intendetl to 6e used for general public vaffic. 77~e purpose of this BMP is to provide a sate, erosion-free access aczoss a stream Cor construc[ion equipment Minimum siandards and speci6cations for the design, conswction, maintenance, and removai of We sWCture should be established by an engineer registered in Califomia Temporary stream crossings may be necessary to prevent rnnswction equip- men[ from causing erosion of the stream and uacking sediment and othu pollutants into tLe sveam: Temporary stream crossings are used as access points io conswction sites when otf~er detour routcs may be too ]ong or burdensome for the conswcuon equipment Often beavy conswction equipment must cross streams or creeks, and detour routes may impose too many consVainLS such as being too nazrow or poor soil strength for the equipment toad- ings. AddiUOnally, the rnntrac[or may find a temporary stream aossing more economical for Gght-duty vehicJes to use for frequent crossings, and may Lave less environmentai impact than conswction oF a temporary access road. In sta i l a ti on/A nnl i ca t i on Temporary access stream crossings s6ould be sized and installed according to tLe drainage design crileria of the local municipality. Design criteria should be based on standard engineering practices for culvert design with provisions for minimizing impacts on disturbed crossing areas. Th~ee types of temporuy access stream crossings may be considered: Temno~r~• A ~e (' ~Iven• A temporary access culvert is effec6ve in convolling erosion but will cause erosion during installation and removal. A temporary culvert can be easily constructed and allows for heavy equipment ]oads. T~~rarv Acresa Ford• A temporary access ford provides little sediment and emsion convol and is ineffecUve in controlling erosion in the stream channel. A temporary ford is the least ezpensive stream aossing and allows for maximum load limits. It also offers very low maintenance. Fords aze moie appropriate during ihe dry season and in arid aieas of Califomia ~~y Accecc Brid~g; With tLe app~opriate materiaLt and designs, a temporary access bridge causes the least erosion of the stream channel crossing during its installation and removal. During tLe long summer construction season in Catifomia, rainfall is infrequent and atany srreams aze dry. Under these condiuons, a[emporuy access fotd may be suf5cienl A ford is not appropriate if construction will continue through the winter rainy season, if summer thunderstorms aze ]ikely, or if the stream flows during most of the year. Temporary acce.~ culverts and bridges s6ould tl~en be considered and, if used, should be sized w pass a signiFicant design s[omi (i.e., az least a 14year stocm). The temporuy stream crossing should be protected against erosion, both to ptevent ezcessive sedimentation in the stream and to prevent washout of t6e cTOSSing (and consequently, costly conswetion delays). Limilationc Special care mus[ be taken when crpssing an environmentally sensitive watenvay. Oils or other potentially hazardous materials shal! not be used for surface treatments, Street mnoff sbould not bc atlowed to spill down crossing sideslopes. ConsWCtion in watercoutses should be at or near the nazural elevadon of ~he stream bed to prevent any potential flooding upsaram of the ciossing. Ip additian, the following limitations may apply; I ESC22 I Co~truc6on Aandbook 5-31 March, 1993 ~d ' , ' ' , , ' ' ' ' ~ , ' , , ~ ~ ~ ~ Addi#ional Information - Temporary Stream Crossing l • May be ezpensive temporary cost • Increased soil disturbance upon installation and removat • Temporary culverts need regulu maintenance and can cause erosion if tl~e culvert becomes clogged. • A temporary ford offers liale if any erosion conVOl in flowing streams and can often make erosion worse. Fords should only be used in the dry sea,wn on dry streams. Conswction in waterwaysis subject to additional permit req~iiements. Contact the local municipal storm water agency Coradditionalinformation. Bank and Shore Protection, CalTrans - November 1970. Best Management Piacdces and Erosion Contcol Manual for Conswcdon Sites, F7ood Control District of Mazicopa Co~mty. Arizona, September. 1992. I . ESC22 I Construction Handbook 5 - 32 March, 1993 i 1~ , ' ~ ' ' ~ ' ' 1 ' ' ' 1 ~ ~ i 1 i Additionai Information - Tem~o~ary stream cross~ny AGGREGATE FILL FILTER CLOTH H16H FLOW AREA -~ - l ~ / AGGRE6A7 ' ~ O' . FILTER CLC FiLL / , ~ ~~i =~~ ~.~.-~ ~, ~ HIGH FLOW AREA '----~+-:::,:.r:::,.:- :::::::.....:::.:r::.-:c. :c..:i8ti7::.-: _. ~:~:::r.::::::_ .."_"'"'......_..... AGGREGAT ~~~~~~~~ O`~~~~'~~~ .FILTER CLOT FILL AGGREGATEi I FLOW AREA `-FILTER CLOTH MULTIPLE PIPES AGGREGATE FILL PER M.A.G. SPECIFICATIONS ~;:_::::/~ ~~ . i ESC22 11 ' ? ' Construction Handbook 5- 33 Marc6, 1993 ~y ' 1 ~ ~ ~ ~ ~ ~ ~ ' ' ' ' ' ' ' ' ' Additionai Information - Tempor~ry stream cross~n9 -~-- ~ ~ ,~`_' , ~~~~ ~ ~ ~~ / `- ` ~~ -~ ~~~~~ _ AGOREOATE BED OV 1 ~_ FILTER CLOTH AOGREGATE APPROACH 5~ I MAXIMUM. S~OPE ON ROAD SURFACE FLOW DIVERTED BY SWALE WATER LEVEL SURFACE FLOW DIVERTED BY SWALE ~ I NEW ROAO ~ ~ORIGINAL STREAM BED I ESE22 11 ' ConstrucHon Handbook 5•34 Ma~ch, 1993 , ~. 1~ ' 1 ' , 1 , 1 ' BMP: CONSTRUCTION ROAD STABILIZATION GENERAL DFSCRIPTION Access roads, subdivision roads, pazking areas, and other on-site ve6icle uansportation rouies s6ould be slabilized immediately aCter grading and fmquendy maintained to prevent erosion and control dusL ' SUTTABLE APPLICATIONS Temporary consauction rraffic. Phased construction projuts and off-site road access. Detour roads. 1 Cons~uction during wet weather. ~ INS1'ALLATION/APPLICATION CRTTERIp ~ Road should follow topographic contours tn reduce erosion of tLe roadway. ~ 77~e roadway slope should not ezceed 15 percent Gravel roads should be a minimiun 4-inch iLick, 2-3 inch coazse aggregate base ~ applied iuunediately after g~ading, or as recommended by soils engineer. • . Chemical stabilizers or water are usually required on gravel ot d'ut roads to preven[ ~ dust (see Dus[ Control ESC 21). REQUIREMENTS Main[enance ' ~ Periodically apply additional aggregate on gravel roads. Active d'ut conswction roads are commonly watered three or more times per day ' during t6e dry season. ' - Inspect weekly, and after each rain. Repa'v any eroded areas immediately. • Cos[ ~ - Gravel consauction roads are moderately expensive, but cou is oRcn balanced by redpctions in consWCtion delay. - No additiona! costs for dust control on conswction roads shou]d be required ~ above ttiat needed to mee[ local air quaii~y reGuirements. LIMITATIONS T'he roadway must be removed a paved w6en constructioa is complete. ' Certain chemical srabiliration methods myy cause stmm water or soIl pollution and should not be used (sea Dust Control ESC 21). Management of conswetion tratlic is subject to air quality control measums, Contact ~ } ~ j~ ~ 9~~~y ~~agement agency. ' ConsirucSon Handbook 5 - 35 Objectives ousekeeping Practic Contain Waste inimiza Disturbed Are ta6iliza Disturbad Area rotectSlopes/Channe Contro! Site Perimeter Control lntemal Erosron Targeted Poliutants ~ Sediment 0 Nut~ients 0 Toxic Materia/s ~ Oi! $ Grease Q Floatable Materials ~ Other Cansiruction Waste 0 Ukely tn Have SJgnfTcantlmpact Q Probable Low or Unknownlmpact ~ Impiementation Requirements Q Capita! Costs Q OSM Cosis Q Maintenance 0 Treining Q Suita6ility for Slopes>5% ~~ High ~ Low ~~ ESC23 Best Managemen Practices Mare6; 1993 ~~ ' ' ' 1 ' ' , ' ' ' ' , ' ' ' ' ' Additionaf Information - Construction Road Stabilization Areas which are graded for conswcuon vehicle transport and parking puiposes are especially suscepGble to erosion and dus~ T6e exposed soil sudace is conunually disturbed leaving no oppormnity for vegetative stabili7ation. Such areas aLto tend to collec[ and transpon runotf waters along their surfaces. During wet weaiLer, they often become muddy quagmires w6icfl generate significant quanuties of xdiment that may pollute nearby streams or be transported off-sitc on the wheels of conswcuon ve6icles_ Dirfsoads can become so unstable during wet weather Wat tLey ace virtually unusable. Ef6cient consaucrion road siabilization not oNy reduces on-site erosion but can significantly speed on-site work, avoid instances of immobilized machinery and delivery vehicles, and generally improve site efficiency and wor}ang condiuons during adverse weather. Installation~Annlication Crneria Where feasible, altematlve routes s6ould be made for conswction vaCfir, one for use in dry condition, the oWer for wet conditions which incorporate the measures listed for this BMP. Permanent roads and parking areas should be paved as soon as possible after grading. As an altemative w6ere conswction will be phased, tl~e earl y application of gravel or chemical stabili7ation may solve potential erosion and stability problems. Temporary gravel roadway sbould be considered during the rainy season and/or on sloges greater tban 5 percen~ W6en gravel mad is needed, apply a minimum 4-inch course of 2 w 4inch crushed rock, gravel base, or crushed surfaring basecourseimmediatelyaftergradingorNecompletionofutilityinstallationwithintherigbt-of-way. Chemicalstabiliration may also be used upon compacted native sub-grade (see the Dust Convol BMP ESC 21). TLese chemical convols sbould be applied per the manufacturu's d'uections. Temporary roads should follow tl~e contour of t6e natural terrain to the maximum eztent possible. Slope should not excced I S percen~ Roadways should be carefully graded to drain transversely. Provide dreinage swales on each side of tbe roadway in ~he case of a crowned section, or one side in ~6e case of super-elevated section. Simple gravel berms witbout a vench can also be used. Installed inlets s6ould be protected to preventsediment-laden water from entering the storm sewersystem (see "Storm Drain Inlet Protection" ESC 54). Best Management Practices and Erosion Control Manual for Conswcaon Sites, Flood Control District of Maricopa County, Arizona September1992. Manual of Siandards of Erosion and Sed;ment Cootroi Measures, Association of Bay Area Governments, June1981. Stormwa[er Management Water for the Puget Sound Basin, Washington 3tate Department of Ecology, T6e Techniral Manoal- Febtuary 1992, Publication # 91-75. Virginia Erosion and Sedimentarion Control Aandbook, Virginia Department of Conservation and Recrea6on, Division of Soil and Water Conservatiou, l991. Water Quality Management PJan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regional P(anning Agency - November 1988. ( ESC23 1 ) Construction Handbook 5-36 March, 1993 17 ' ' - ) ' ' ' ' ' ' ' ' ) ' ' ' , ' ' 1 i' ' BMP: STABILRED CONSTRUCTION ENFRANCE objectives ousekeeping Practica ~ Contein Waste i`^~~ h' ' r inimize Disturbad Are ; : ' ` Stabiliza Disturbed Area ~ t Protect Slopes/Channe/s ~,•^-' " ntrolSitePerimet Confrol lnteme/ Erosion GENERAL DFSCRIPTION Targeted Pollutants 'Ihe construction entrance practice is a stabilized pad of aggregaze under)ain wiW filter Q~iment cloth loca[ed az any point where haffic will be entering or leaving a construction site to ot from a public right-of-way, streeG al)ey, sidewalk or parking area Stabalizing the 0 Nuirienta construction entrance significanUy reduces the amoun[ of sediment (dust mud) tracked Q Toxic Materiale off-site, especially if a washcack incorporated for removing caked on sediment Q Oi/ d Grnase SLJTTABLE APPLICATIONS ~ Fbatsble Maferials All points of construction ingress and egress. Q Other Construction Unpaved areas where sedimen[ tracking occurs from site onto paved mads. Wsste INSTALLATION/APPLICATION CRII~RIA ~ Ukey m Havs Construct on level growd where possble. S7yn/Heant Jmpaet Stones should be I-3 incltes. ~ Probe6MCowor Muiimum depth of stones s6ould be 6 inches or az recommended b soi]s en i unlmownlmpsct y g neer. Length should be 50-toot minimum, and 30-foot minimum width . Ptovide ample turning radu as part of entrance. ~mplementaUon Requirements REQZ7IREMENTS Q Capita! Casta M~~n~~ O 06M Coata - Inspect monthiy and after each rainfall. - Rep~ce g[avel m~eria( when surface voids aze visible. 0 Meintenance - Remove all sed~ent deposited on paved roadways withm 7A hou~. ~ Treining - Remove gravel and filtcr fa6ric az compleflon of conswction Q SuifabpJty /or • CosC Average annual cost for installation and maintenance (Source: EPA,' 1992) Slopea>5x - ~thoutWash Rock: $1500 each, - Wi~h Wash Rock: 32200 eacit. LIMITATIONS • Requ'ves periodic top dressiog with addifiooal stones. . ~ Should be used in cxiojimction with Street sweeping oa adjxent public rightof-way. ~ Hfgh ~ Low ESC24 ~St Managemen PraCtices Cortctruction Handbook 5-37 March, 1993 ~~ 1 ' ' ' , t ' ~ ' ' t , ' ' ' Additionai Information - Stabilized Construction Entrance A stabilized consuuction envance is a pad of aggregate underlain with Fil[er cloth lorated at any point wheie traffic will be wtering or leaving a construcaon site to or from a pubL"c right-of-way, sVeet, alley, sidewalk or parldng area. I'he purpose of a stabilized conswcrion entrance is to ieduce or eliuunate t6e tracking of sediment onto public rights-of-way or sueets. Reduang trnckout of sediments and ot6er pollutants onto paved roads helps prevent deposition of sediments into local storm drains and production of airbdme dust. Whero traffic will be entering or leaving, a stabilized consauction enliance should be used at all poinLS of construction ingress and egress. NPDFS pecmits require tLat appropriate measures be implemenled to ptevrnt trackout of sediments onto paved roadways, which is a signitirant soutce of sediments derived from mud and d'ut cazryout from tLe unpaved roads and conswction sites. Stabilized construction entcances are moderuely effecrive in removing sediment from equipment ]eaving a conswction site. T6e entrance should be build on tLe level groimd. Advantages of the StabIlized Conswction Entrance is tbat it dces remove some sediment from equipment and serves to channel consWCtion traf5c in and out of the sile az spe~ed locatioos. Efficiency is greatly mcreased when a washing rack is included as part of a stabilized construction entrance. 7Le aggregate for a stabilized constrnction entrance aproas should be I tn 3 inches in size, washed, well-graded gravel or crvshed *ock_ Minimum apron dimensioos of 30 ft x 50 tt and 6 inches deep is adequate for two-way ingress/egress traffic. 'Ihe entr~ce must be properly gaded to prevent runoff from leaving the consWCtion site. WLen wash areas are provided, washing is done on a reinforced conaete pad (if significant wazhing is necessary) or in an area stabilized with cnuLed stone whicL drains intp a properly constructed secliment .trap or basin (ESC 55 and 56). Sediment barriers are provided to prevent sediments from entering into Ihe stomiwa~er sewer system, ditch, or waterway. I.lIDit3t1SS111T ~ • Cooswct on level groimd. Stabilized ca~sWCtion envances are rather ezpensive ro construct and w6en a wash rack is included, a sediment trap of some kind must also be provided to collect was6 water nmoff. Requues periodic top dressing wit6 additional stones. Should be used in conjimcdon wiW street sweeping on adjuent public rightof-way. REFERENCES Best Management Pracdces and Frosion Control Manuai for Construcfloo Sitcs, Flood Control District of Mazicopa Co~mty, Axizona, September 1992. Manual of Standards of Fsvsion and Sediment Control Measures, Association of Bay Area Govemment5, June 1981. Pioposed Guidance Specifymg Management Measiues for Sources of Nonpoint Pollution in Coastal Waters, Work Group Workin8 paprr. USEPA, Aprit, .1992. Stwmwater Management Water for tLe Puget Sormd Basin, Washington Srate Depattment of Eoology, 'ILe Technical Manual- Febmaiy 1992, Publication # 91-75. V'uginia Erosion and Sedimentation Controt Handbook, Virginia Depariment of Ca~servazion and Recreation, Division of Soil and Wazer Conservation, 1991. Watet Quality Management Plan for tbe I.ake Tahce Region, Volume II, Hand6ook of Manage,ment ~~4 Practices, Ta6oe Regional Planning Agency - November 1988. 1 F~.a Conttruction Handbook 5-38 March, 1993 ~~ '. ~ _ , ~ ~ ' , ' , ' ' J ' ' ' , ' , ' ' 1 ' Additional Information - stabilized construction Entrance ~ / VEHCLE LENGTH ~ a ~' , ~~' ~~~ ~_ ~ '~.' .` .1'• .. ~ - -_i . A . . ~ O . ~. ~DRAIN SPACE MET4,L' BAR REINFORCED CONCRETE CHANNEL/DITCH BOTTOM . WASH RACK (SCHEMATIC) / ~R20' P~F.~' Sp" M~N yJ~~-oQ,O ~ ~/~\G ~ ~,? FILTER FABRIC 1" TO 3° COARSE Z AGGREGATE ~ in ~Te D -ONSTRIx'TlOh ~"TRAtvCE DITCH TO CARRY WASH WATER TO SEDIMENT BASIN OR TRAP K Construction Handbook 5-39 March, 1993 1~_ ' , , 1 ' , , ' ' ' ' ' ' ' ' ' ' ' ' BMP: EQRTH DIKE objectives Housekeeping Przc6ces _ Contain Wast . Minimize Disturbad Areas ' ' ' Stabilize Disfurbed Areas rotect Slopes/Channe _ - ontrol Site Perimete ontrol lntemal Erosio GENERAL DFSCRIP'PION Targeted Pollutants The [emporary earth dike is a temporary berm orridga of compacted soil, used to divert runoff ~ Sediment or channel wa~er to a desired ]ocation. ~ 0 Nutrients SUITABLE APPLICATIONS 0 Toxic Maferia/s Farth dikes aze typically used w divert concenvated runoff iLrough disturbed areas into Q Oil & G~ease another BMP. (e.g., sediment basins), to divert runoff away from distutbed or uns~able slopes, t bl M i l ~ Fl to divert runoff fmm off-site and undiswrbed azeas azound disturbed areas, and at a oa a e ater a s containmentforconsnuctionmaterialsandwastes.7Ledikesshouldremaininplaceuntilthe 0 OtherConstruction diswrbed areas are permanently stabilized. The dikes mustbe on-sile and mustsafely convey -Naste anticipated flood flows. ~ Llkety to Heve INSTALLATION/APPLICATION CRI'[~RiA Slgnlneant lmpect All dikes s6ould be compacted by eart6-moving equipment ~ Proba67e Lcw or All dikes sL ld h iti d n Unknownlmpact ou ave pos ve rai age tn a stabilized ouUe~ Top width may be wider and side slopes may be tlatter at crossings for consWCtion ~mplementatlon uaffic. ' Requirements Dikes s6ould d uect sediment-laden ronoff into a sediment uapping device. Dikes should be stabilized with vegetation, chemicals, or physica] devices. 0 Capita/ Costs ~ O&M Costs REQUIREMENTS Q M i t Main[enance a n enance Inspect periodically and after every signi5cant rainfall; repair as necessary. 0 Treining ~ COSt Q Suitability for - Costrangesfrom$15to$SSperfootforbott~earthworkandstabilizationanddepends Slopes~5% on availability of ma[e~ia1, site location, and access. LIMTI'ATIOIVS Dikes s6ould notbe used for drainage areas geater tban 10 acres, oralong slopes greater than lOpercent Forlargerareasmorepa~manentdrainagestruct~uesshouldbebuilt Alldrainage structures should be buil[ in compliance with local municipal requirements. ~ Hj9h ~ Low • F,arth dikes may create more disturbed area on site and become bazriers ro conswction E S C30 equipmen4 • E L dik art es must be stabilized immediately, which adds cost and maintenance concerns. • Diverted stocm water may cause downsueam flood damage. • Dikes should not be conswcted of soils wlri~ may be easily e~oded. "' • Regrading the site to iemove tl~e dike may add additional cost Best Managemen . Practices Conctruction Handbook - 40 March, 19 3 ) ~~ ' ~ i ' ' ' ' i ' i t I~ ' ' ' ' t - ~ ~ ~ AddItI011a1 111fOC~T18t1011 - Earth Dike The ~emporuy eanh dike is aberm orridgeof compacted soil, located in such a manneras to diveR storm water[oasediment [rapping device or stabiliied outlei, thereby reducing ihe pcxential for erosion and offsite sedimentatioo. Eartb dikes can aLso be used to divert runoff from off-site and from undistucbed azeas away from disnirbed aze~, and to divert sheet flows away Irom unprotected slopes. An earth dike dces not itself control erosion or remove sediment from runoff; a dike prevents erosion by directing nmoff to an erosivn control device such az a sedimwt trap or d'uecting cunofl away from aa erodible azea Temporary dive~ion dikes should not adversely impact adjacent properties and must conform to local floodplain managemen[ regulations, and should not be used in ateac with slopes steeper than 10%. • The advantages of the tempcxary earih dike include the ability to 6andle flows from ]arge dcainage areas. • Oncestabd'ued,earthdikesrequirerelativelylittlemaintenance, Additionally,ti~eearthdikesareielativelyinezpensive ro install since the soil mazerial required for conswction may bc available on-site, and can be conswcted as pan oE the uutial grading operations, while tLe equipment is on-site. • Uses on-site materiais. Insta11a6on1Annlication riteria TemporaryeartLdikesareapractical,inezpensiveBMPusedtodivertstormwaternmoff, Temporuydiversiondikessbould be ins~alled in t6e following manner. 1. AII dikes s6ould be compacted by earth-moving equipment 2 All dikes should Lave positive drainage w an oudeL , 3. All dikes s6ould have 2:1 side slopes, 18 inches mmimam height, and a minimum top width of 24 inches. Top width may be wider and side slopes may be flaperat crossmgs fa conswction traffic. 4. TLe outlet from the earth dike must function wiW a minimum of erosion. R~moff should be comeyed to a sediment uapping device such as a sediment trap (ESC SS) or sedimen[ basin (ESC S~when ei[her t6e dike channel or ihe drainage ama above We dike are not adequately stabilized. 5. Tempotary stabilization may be achieved using seed and mulching for slopes less than 5'~0, and either rip-rap or sod for slopes in ezcess of 5%. In either case, stabIIization of [he eartL dike should be completed immediately after conshuction or prior to t6e fust rain. 6. IC riprap is used to stabilize We channel formed along tbe [ce of the dike, tbe following typical specifiptions apply: CHANNII, Ripgpp ~$ STAR .iZAT10N OS-1.096 4" Rock I.1-2.0% 6' Rock 2.1-4.096 8" Rock 4.1-5.096 8-12" Riprap 7. 'ILe srone riprap, recycled conaete, etc. used for stabili7atioo s6ould be pressed inW the soil wiW conswction equipment 8. Flter cloth may be used ro cover dikes in use for long periods. 9. Constroction activity on t6o eaitL dike should be kept w a minim~. Best Management Pcactices and Erosion Cantml Manual for Coasm~cflon Sites, Flood Contm] Distxict of Maricopa Camty, Arizona, September 1992. "DraR - Sedimentation and Flosion Control, An Inventory of Ciment Pracfices", U.S.EP.A., April, 1990. I ESC30 I Cons4uction Handbook 5-41 Macch, 1993 ~ ' ' ~ , ' ~ ' ' ' , ' ' ' ' , ' ~ ~ Additional Information - Eann ~~ke Erosion and Sediment Control Handbook, SJ. Goldman, K Jackson, T.A. Btusetynsky, P.E., McGraw Hill Book Company. Manual of Standards of Erosion and Sed'm~ent Control Measures, Association of Bay P.rea Goveroments, June 1981. Water Quality Management Plan for tLe Lake Tahce Region, Volume II, Han~ook of Managemeo[ Practices, Tahce Regional Planning Agency - November 1988. I ESqO ( r Const`uction Handbook 5- 42 March, 1993 H~ i ' ' ~ ) ~ ~ ~ ' , ~ ~ ) II ' , ' ~ , , ~ ' j Additionai lnformation - Eartn ~itce s COMPACTE~ FIL~ ~ ~,_„ C ~(~ ~ ~ Z : I SLOPE I -,~1I OR F~ATTER. I~I I- a t~ ~~~ R~ BOTH SIDES I~I I~ ~II ~I.\ ~ GRAOE UNE I ~~~ ~~~L~ i / / ~/ ~~~ ' ~ ~ ~ ~ ~\~~` ~~-,r-~-~iiJ_~_--- - -~--~-- ~ ,,.y ~y~j\~ \~j\~~/ ~~/~~~~~~~/~~~ \~~\// STABILIZATION AS REOUIRED ON STEEP SLOPES EXCAVATE TO PROVIDE REOUIRED FLOW WIDTH AT FLOW DEPTH REDUIREMENTS BASED ON UPSTREAM DRAlNAGE AREA TEMPORARY DIV RSInN n~KF E5q0 ~ ~. DIKE 1 DIKE 2 (5 ACRES OR LESS7 (5-10 ACRES) A-DIKE HEIGHT 18' 3g~ 8-DIKE WIDTH 24" 36~ C-FLOW WIDTH 4' g• D-FLOW DEPTH 8" 15"' ' Construction Handbook 5- 43 March, 1993 ~y ' ' ' ' ' ' ' , ' ' ' ' ' ' ' 1 ' BMP: TEMPORARY DRAINS AND SWALES Objectives Nousekeeping VracGces . Contain Waste _ Minimize Disturbed Areas _ Stabilize Disturbed Areas rotectSlopes/Channe - Contro! Site PeNmete ontro! Intemal Erasio GENERAL DFSCRII'TION Targeted Pollutants Temporary drains and swales aze used to divert off-site runoff uound the conswction site, ~ Sediment divert runo(f from stabilized areaz around distu~ed area5, and direc[ nmoff in[o sediment basins or tcaps. ~ Nutrients 0 Toxic Materials SUITABLE APPLICAT'IONS ~ Oil & Grease Temporary drdins and swales are appropriate for diverting any upslope runoff around ~ Fl t bl M i unsrabilized or dismrbed azeas of ~he conswcuon site: oa a e afer afs Preven[ slope failuies. Q Other Construction Prevent damage to adjacent property. Waste Prevents emsioo and transport of sediments into water ways. Tocteases [Le paential for infilUation. ~ Ukaly to Have Diverts sediment-laden runoff into sediment basins or traps. SlynlHcant tmpact 0 Probab/e Low or INSTALLATTON/APPLICATION CRI'I'~RIA Unknown Impact Temporarydrainageswaleswilleffectivelyconveyruno(fandavoiderosionifbuiltproperly: ~mptementation Size temporary d~ainage swales using Iocal drainage design cri[eria Requirements A permanent drainage c6annel must be designed by a professional engineer (see the Iceal drau~age design criteria for proper design). Q Capita/ Cas~s A[ a minimum, the drain/swale should conform tn piedevelopment drainage paUems ~ O&M Costs and capacities. i t ~ M Construct ILe drain/swale with an uninteirupted, positive grade to a slabilized outlet a n enance Provide erosion protecdon or enugy dissipation measures if the tlow out of t6e dtain ~ Tralning or swale can reach an erosive velocity. Q Suitabllity for Slopes>59: REQUIRF.MENTS • Maintenancc - Inspect weekly and atter each iaia - Repair any emsion immediately. - Remove sedime.nt which builds up in the swale and restricts its flow qpxity. • Cost ~ High ~ Lcw TL f - e cost o a drainage swale inciea.us with drainage area and ~lope. Typical. swa]es for controlling intemat erosion are inexpensive. ~ C(~~ ~ a~ V LIMITATIONS Temporary draic~s and swales or any otLer diversion of nmoff should not adversely impact upstream or downstteam proparfles. Temporary drains and swales musc conform to iocal floodplain management iequire- ments. Best Managemen Practices ,l ' Construction Handbook 5- 44 March, 1993 ~3 ' ' , ~ 1 ' r ~ ' ' 1 '^ r r r ' r ra r AddIt1011a1 It1fOCi1'18tI0C1- Temporary Drains and Swales Slopes tbat are formed during cut and fill opeiations should be protected from erosion by rurroff. A combinauon of a temporary drainage swale and an earth dike (see ESC30) a[ the top of a slope cau safely divert runoff to a locatioo where it can safely be brought to the bottom of the slope (see Pipe Slope Drain FSC32). A combination dike and swale is easily conswcted by a single pass of a bulldozer or grader and compacted by a second pass of the tracks or wheels over the ridge. Diversion swc[ures should be installed when the si[e is initially graded, and remain in place imtil post-construction BMPs are installed and/w the slopes aze stabilized. Diversion practices concentiate tLe vol~e of surface runoff, increasing its velocity and erosive Force. Thus, the tlow out of the drain or swale mustbe directed onto a stabilized area or into a grade stabilization structure. A swale should be stabilized using vegetation, c6emical treamient, rock rip-rap, matting, or other physical means ot atabilizauon, if significant erosion will occur. Any drain or swale cvhich conveys sedimenbladen runoff must bc divened into a sedimen[ basin or trap before it is dischazged from tl~e site. Installa[ion~App]iqtiop .ri[ .ria Diversiondrainsorswalesareonlyeflectiveiftheyareproperlyinstalled. SwalesaremoreeffecavetLandikesbecausetliey tend to be more stable. The combination of a swale wi[h a dike on the downhID side is t6e most cost-effective diversion. Standard engineering design aiteria for small open channel and closed conveyance systems should be used (see the local drainage :design manual). Unless Iceal drainage design criteria state otherwisc, drains or swales shou]d be designed as follows: • No moic than 5 acres may. drain to a iemporary clreia or swale • Placc ihe drain or swale above, not on, a cut and fill slope • Swale bottom widlL should be at least 2 ft. - • Depth of the swale should be at least 18 inches • Side slopes s6ould be 2:1 or flaaer • Ihain or swale should be layed az a grdde of at leas[ 1 percen4 but not more ihan 15 percent • T7~e swale must not be overtopped by the 10-yeat, 24bour storm, irrespective of tLe design criteria stated above • Remove all trces, stumps, obswctions, and other objecaonable material from tLe swale w6en it is built •. Compact any Fll materiai along tLe path of ihe swale • Stabilize all swales immediately. Seed and mulch swales at a slope of less t6an 5 percent, and use rip-rap ~ sod for swales wiW a slope between 5 and 15 percent • Do not operate conswction vehicles across a swale unless a stabilized crossing is provided. • 'Ibe cost of swales and otLer diveision devices is geneially induded in tLe eart6work cost, as a sepazatc item under fhe grading budget oF tlie project construction contract ~~~ Best Management Practices a~ Flosion Convol Manual for Construction Sites, Flood Control Distiict of M~icopa Coimty, Arizcwa, September 1992. "Draft - Sedimentation and Fiosion Control, An Inventdry of Cutrent Ax6ces", U.S.EP.A., April, 1990. Manual of Standards o[ Erosion and Sediment Control Ivieas~ues, Associatiou of Bay Area Govemments, June 1981. Stom~water Management Water for the Puget Sound Basin, Washington State Department of Ecology, TLe TecMical Manual - Febmary 1992, Publication # 91-75. ESqi VVater Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management ~ Piactioes, Tahce Regional Plaming Agency - November 1988. Construction Aandbook 5-45 March, 1993 ~ ' ~ 1 1 1 t ' 1 ,^ ' , 1 1 ' , ' ' ' r Additional Information - Temporary ~rains and swa~es ~3:1 OR F~ATTER ~ I8" (MIN.) _---~- I II~'~ . i_y ~ I ~ ~ I~~ ~ I~'' ~~~~~Q I I r ~ 1 t~~ ~H, ~ , , ~ 2' (MIN.) STABIIiZATION LEVEL CROSS SECTION O.Sx OR STEEPER. . DEPENDENT ON TOPOGRAPHY STABLE OUTLET REOUIRE .~~FLOW ~~FLOW ~~ TEMPORARY DRAfNAGE SWALE ESq1 ~-.~ ~ Construction HandUook 5•46 , March, 1993 ~~ , ' ' } , ' ' ' ' , ~ ' ~ ' ' ' ' r~ , BMP: SLOPE DRAIN Objectives Housekeepirtg PracUces ~ Contain Waste Minimiza Disturbad Araas Sfabifiza Disturbed Areas rotectSlopes/Channel -1% Control Site Perimeter Control Intemal Erosion GENERAL DFSCRIPTION Targeted Pollutants A temporary pipe or lined channel to drain the [op of a slope to a stable discharge point at ibe S Sediment bouom of a slope wi~hout causing erosion. ~ Nutrients SUITABLE APPLICATIONS ~ Toxic Materis/s • Where concenvated f7ow of surface runotf must be conveyed down a slope in order to ~ OilB Grease preventerosion. Drainage tor top of slope diversion dikes or swates. ~ Flaeta6le Materisfs Emergency spillway for a sediment basin. ~ Other Canstruction Drainage for top of cuUfill slopes whete water can accumulate. Waste Tbe types of slope drain can indude: ~ Ukay fa Have Pipe drops. . S1gnlRcant!lnpact Flexible dOwndrains. " ~ ~ Probab/e Low or Unknownlm ect • Sec6onal do d i p wn ra ns. Linea ce,Tace drains. ImplementaUon Requirements INSTALLATION/APPLICATION CRTIERIA Secure inlet and surro~md with dikes ro preven[ golly erosion, and ac~cLor pipe to 0 Capital Costs slope. Q O&M Costs • Size [o convey at least the peak of a 10-year, ?A-Lour sto~ (See locai tlood wntrol p Maintenance agency for requirements). Stabilize outleL ~ Trsining 0 Suitebility for REQUIREMEN7'S Shpes>SX • Main[enance - Stnuture must be inspected regularly and afta stomu. - Inle[ must be Iree of undercutting and no water s6ould cucumveot the entry. - Outlet should not produce erosion; velocity dissipators must be maintaiced - - Pipe anchors must be c6ecked to ens~ue that the pipe remains anchored to the slope. ~ High ~ Low Cost - CalTrans Cost Schedule gives regiona! costrmges. ESC32 ' LIMTI ATIONS Mazimum dreinage azea per slope drain is 5 acres. (For large aceas use a paved chute, rock lined channel or additional pipes.) • Clogged slope drains will force water around the pipe and cause slope emsion. Dissipation of high flow velocities az Ihe pipe oudet is required to avoid downstream Best erosion. Managemen • Failure can result in f]oodin and severe erosion PraCtiCes Constcuction Handlwok 5 - 47 March, 1993 $6 , , , , t ~ ' , ' ' ' ' ' ' ~ ~ Additional Information - sioPe ~rain The slope drain may be a rigid pipe, such as com~gated metal, a flexible condui4 or a lined teirase drain with ihe inlet ptaced on ihe top of a slope. "Ibe drain conveys concentraced runotf down to the bottom of the slope_ The BMP typically is used in combinauon with a diversion convol, such as a temporary dike or swale, at ihe top of ~he slope, and serves as a temporary BMP to reduce or eliminate stope erosion until pem~anent SMPs are instailed and the slope is stabilized. 7Le slope drain is applicable for any conswction site where concentrated surface runoff can acc~ulate and must be conveyed down the slope in order to prevent erosion. T6e slope drau~ is effecuve because it prevents the stormwater from flowing directly down Ihe slope by confining alt the runoff into an rnclosed pipe or channel. Due to We time lag between grading slopes and installation of permanen[ storm water collection systems and slope stabili7auon measuies, temporary provisions to intercept mnoff are sometimes necessary. Particularly in steep terrain, slope drains can protect unstabilized areas from erosion. Typical uses include: • Emerge~y spillway for a sedimen[ basia • Drainage for tDp of cudfill slopes where storm water can accumulate and must be conveyed down the slope. Inst?1lauon~Annlication C'rit ria Temporary slope drains are highly etfective in eliminating slope erosion. Installation and maintenance requiremencs are small, especially when flexible pipe is used. General cri~eria: • Gullyerosionist6emajorproblemwithslopedrains.InletsWCturesmustbesec~elyenvenchedandcompactedtoavoid sevue gully erosion. • 'Ibe drain must be securely anchvied to the slope and must be adequately sized to carry the capacity of the design slorm and associated forces. • 'Ihe oudet must be stabilized with ri~rap, concrete or other type of energy dissipator, or d'uected inw a s~able sediment uap or basin. • A debris rack is rernmmended at tLe inle4 ~ s6ould be encouraged for larger pipes and at the outlet as a safety device to prevent small c6ildreu from entering the pipe. Materials: ' Material seleclion and criteria for the pipe slope drain is of[en esiablished by tt~e local municipality. Soil type, iainfall pattems, conswction schedule, and available supply are some of We factors tn be consideted. T6e following types oC slope drains are commonly used: • JY'd~_ 'Ihis type of slope dram is atso Imown as a pipe drop. '17ie pipe usually consists of conugated metal pipe or rigid plastic pipe. The pipe is placed on undisturbed or compacted soil and secured inro the slope. One foot minim~ cover is reqt~ired on the pipe, and concrete thrust blocks must be used when required by t6e municipality or warranrcd by the calculated thrust forces. Collazs should be properly installed and secuced with metal strappings or watenight collars. • ~exible Pin~; 7'he flezible pipe slope drain consists of a flexible conduit of 6eavy duty material. The condui[ mazerial is securely anchored into We slope and connections are watertight The conduit should be securely fastened to the metal iNet and oudet conduit sections wiW matat strappings or water 6glu collars. • CeciionaDown rainc•'~'besectionaldow~drainconsistsofpre-fabricated,sec6onalconduitofhalf-roundorthird-round material. ~Le xctional dowodcain pedorms similaz to a tlume or chute. The pipe must be plazrd on undisturbed or compacred soil and secured 'mto che slope. • concrete-tined Ter7a Drairc TLis is a concrete channel for draining water from a tenace on a slope to the next level. Thes~ drains are after permeoant swcwres wlvch s6ould be designed according to local drainage design criteria. , ~ ESC32 ~ Construction Handbook 5-48 March, 1993 ~~ ' , _ ; ~ 1 ' ' ~ , ' 1 ' 1 ' ' ' ~ ' } ~ Additional information - siope ~rain Design: Unless specified by tLe local municipaliry, the capacity for temporary drains should be sufficient to 6andle the peak runoff from a 10-year, 24bour rainfall evenL 7'he pipe size may be computed using ihe Ra6onal Method or amethod establis6ed by the local municipality. Higher Ilows must be safely stored or routed to prevent any offsite concentraUOn of flow, and any erosion of tLe slope. As a guide, temporary pipe slope drains should not be sized smaller than s6own in the following table: MINIMUM MA}QM[JM PIPE DIAMETER DRAINAGE AREA (ACRES) 12" OS 18" I.5 21" 2.5 24" 3.5 30" 5.0 Pera~anent improvements must be designed and installed iF ihe dcainage area is grea[er tLan 5 acies. The following additional design criteria should be considered: Construct the pipe sIope d~ain entrance of a standard Dared end section with a minimum 6-inch metal tce plate to prevent runoff from undercutting We pipe inlet The slope of the entrance is usually az least 3 percent ThorougLly compact We soil around and under the pipe and entrance section. . Securely fasten the slope drain sections togetber, have gasketed watertight fittings, and securely anc6ored into the soil. Secure the flarcd 'uilet section to the slope drain and bave watertight connectmg bands. • Use interceptor dikes to direct nmoff intn a slope drain. T6e height of the dike should be at ]east 1 foot hig6a at aIl points Wan the top of the inlet pipe: If tLe pipe slope dtain is conveying sediment-laden water, direc[ all flows into a sediment trap (ESC55) or sedimen[ basin (ESCS~. Unless the pipe d'uectly enters a sediment trap/basin, stabilize the area below Ihe outlet with a ripcap apron. i.imi alions . . Installafion is cri[ical f~ effective use of Ihe pipe slope drein to minimize potential guily erosion. Ma~cimum drainage area per pipe slope drain is 5 acres. For larger amas usc a paved chute, rock lined channel or addidonal pipes. (Sec tbe Iocal muniripaliry for drainage requirements) During large storms, pipe slope drains may become clogged or overcharged, forcing water azound the.pipe and causing exveme slope erosioa • Suvchues for dissipation of Ligh flow velocifies az the pipe outlet mnst be consm~cttd ro avoid downstream aosion. • Failure of this type of temporary stcuctute may tesult in flooding and sevete emsion. • If the secfional doavdrain is not sized coirectly, the nmoff pn spID ova the drain sides causing gully erosion, and pcxenfial failu:e of tbe struchue. ESC32 """~~ R.cm. Construction Handbook 5-49 March, 1993 CJ'~ ' ' 1 ' '^ ' 1l 1 1 ' ' ' ' Addifional Information - siope ~rain ~x~tvcEs Best Management Practices and Erosion Control Manual for Construction Sites, F7ood Convol District of Mazicopa Coimty, Arizona, September 1992. "D~aft - Sedimentation and Erosion Control, An Inveutory of Cuirent Practices", U.S.E.P.A., April, 1990. Stom~water Management Water for the Puget Sound Basin, Washingwn Sta[c Departmen[ of Ecology, Tl~e Technical Manual - Febmary 1992, Publicaflon # 9]-75. Wa1er Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Prectices, Tahce Regional Planning Agency - November 1988. ~ Construction.Handbook 5-50 ESC32 ~ ) e..a~.. March, 1993 ~a' , ' '. i 1 1 1 ' r ' t ' , ' ' ' ' 1 , Additional Information - stoPe ~rain ~ EARTH DIKE _ \ , 1'1i~, " l~- ~ i ;_~//= ~/-~~ I I 1=1 I I- I . _~~~ ~ ,z~~~~ i - i-i i i-iTi- ~11= ~,~/~~ i l_I I I_I 11=11 -;- ;~ _; III ~,I~~,, ~i~. ~ \-`/% ~~~~ I I I, ; .I ~- -~~~.~~ ~~ ,,,,~- - ~ ;~!`1~i~~ ~, STANDARD F~ARED kY I ENTRANCE SECTION ' APRON q• ~ MIN. IN~ET SLOPE 3z MIN. SIDE SLOPE = 2:1 EARTH DIKE ~ I_' I I I I ~ ~_ ~ ~~~2~ . CORRUGATED I ~• I- I~ I~ I~ I~ METAL PIPE I I ~ i. (D) 6D ~ ~ AT LESS THAN 1x SLOPE 0 ~ 3D+2 RIPRAP SHQULD CONSIST OF 6" DIAMETER STONE PLACED AS SHOWN AND SHOULD BE A MINIMUM OF 12" IN THICKNESS. PIPE SLOPE DRAIN (RIGID) 13: K+ Constraction Handbook 5 - 51 ~0 March, 1993 , - ' ~ ~ ~ , ' , ' ~ , t ' , ' , t ~ , 1 Additionai Information - sio~ ora~n ALTERNATI SEDIMENT (SEE ESC ° LENGTH AS NECESSARY TO ~0 THRU DIKE H = D~12" PIPE ELBOW - WATERTIGHT- CONNECTING . BAND FLEXIBI.E PIPE ~--4' MIN e LESS THAN iz SI.OPE SEDIMENT TRAP 6"' MIN CUTOFF WALL ~ ~ 0 3D RIPRAP SHOULD CONSIST OF 6' ~ DIA STONE PLACED AS SHOWN. OEPTH OF APRON SHOULD EOUAL THE PIPE DIA AND RIPRAP SHALL BE A MINIMUM OF 12' IN THICKNESS. ALTERNATIVE SEDIIv1ENT TRAP• RIPRAP PLAN PIPE SLOPE DRAIN tFLEXIBLE) ~- 1 ~ 1 Construction Handbook 5-52 iii- 3f 5`-~QE Q~o~E S.~EEQEF March, 1993 ~\ , ' ~ ~. t ' ' ' ' , , ' ~ , ' ' ' , ' ' ~ ~ ~ BMP: OUTLET PROTECTION objectives Housekeeping PracGces i ~\ ~ / ~ ~1~ • 1- Contain Waste ~ ,}, ~~_~ ~ r • K' ~~ ~4finimize Disturbed Areas i j J• e ,~ ~ , /.. StabilizeDisturbedAreas ....-_. ~ * ' ~~ i rotect Slopes/Channe u ~` ~ - r / ControlSitePerimeter _ ~~~t Control lntemal Erosi on GENERAL DESCRIPT'ION Targeted Pollutants Rock ou8et protection is a p6ysical device composed of rock, grouted riprap, or concrete rubble which is placed aC tt~e ouUet oC a pipe to prevent scovr of t6e soil caused by 6igh ~ Sediment pipe flow velociues, and to absorb flow energy to produce non-erosive velceiues. Q Nutrients SUITABLE APPLICATIONS ~ Tozic Materials Wherever discharge velocities and energies a[ the outlets of culverts, conduits or 0 Oil & Grease channels aze sufficient to erode tl~e next downstream teach. 0 Floata6le Materiafs Rock outlet protection is bes[ suired for temporary use duiing consWCUOn because i[ Q Otbe~ Construction is usually less expensive and easier to install than concrete aprons or energy Waste dissipatocs. A sediment nap below ihe pipe outlet is recommended if runoff u sediment laden. ~ ukey fo Have Permanent rock riprap protecuon should be designed and siied by the engineer as part Slgnl~wnr Impxt of ~he culvert, conduit or channel design. 0 Probeble Low o~ Gro t d ri h Unknown/mpect ~ u e prap s ould be avoided in areas of freeze and Waw because the grout will break up. Implementation ~ Requirements INSTALLATION/APPLICATTON CRTi'ERip Rock outle[ protection is effective when the rock is sized and placed piopedy. WLen this 0 Capital Costs is accomplis6ed rock outlets do mucti to limi[ erosion at pipe ouUets. Rock size should be ~ 08M Costs increased for high velocity tlows. General tecommendaUOns for rock size and leng~h of Q Maintenance ou8et pcotection mat are presented in the additional information sheeL Best results are i i ~ T obtained when soimd, dwable, angular rock is used, CalTrans Standard Specifications or rs ng n the local municipatity caa provide additional specificatlons for conswcung oudet protec- ~ Suitabiliry tor tiondevices. ~ ~ . Slapes>59G REQUIREMENTS Maintenance - Inspect aRer each significan[ ~ain for erosion and/~ disruption of We rock, and cepair immediately. ~ Hi h ~ L Grouted or wire-tied rock ri ra can i i i i g ow p p m n m ze ma ntenance requirements. • Cou - CalTrans Cost Schedule gives regional cost ranges. C A G~~~} O LIMTTATIONS • Large stoims often was6 away the rocic ouUet protection and leave the azea suscep- tible to erosion. • Sedimeat qpwred by t6e rock outlet protection may be di@'icult to remove without Best removing me rock Managemen • OuOet protection may negatively impact ibe channel habitat PraCtiCes Construction Aandbook 5-53 Marc6, 1993 ~r ' , ~ , ' ' , , ' ' ' , ' Additional information - outiet Protection OuUet pro~ection is needed w6ere discharge velociues and enargies at the outiets of culveru, condui~s or channels are sufficient to erode ihe immedaie downstream reach. 7Lis pracuce protects ihe inlet or ou~et from developing small eroded pc~ols (plange pools), and protuts against gully erosion resulung from scouring at a culvert momh. ftcek outlet protection is usually less expensive and easier to install t6an concrete aprons or energy dissipators, I[ also serves to trap sediment and reduce tlow velocities. As with most cbannel design projects, dept6 of tlow, roughness, gradient, side slopes, discharge rate ar~d velocity s6ould be considered in !he outlet design. Compliance to local and state regulations should also be considered while working in environmentally sensitive sveambeds. General recommendations for rock size and length of oudet protection mat is shown in tLe rock outlet grotection figure. Best resulis are obtained when sound durabie, angular rock is used. Rock depth and o~tlet protecuon length are govemed by We dischazge pipe size, but Lydcaulie calculaUOns and velceiues s6ould be used w determine teng~h. Your local municipality or CalTrans sbould be consulted for appropriate sizing criteria in your area Best Management Practices and Erosion Control Manual (or Conswction Sites, Nlood Control Disvict of Mariposa County, Arizona, September 1992 County of Sacramenw Improvement Standards, Sacramento County - May 1989. Environmental Criteria Manual, City of Austin, TX, 1989. Erosion and Sediment Convol Handbook, SJ. Goldman, K. Jackson, T.A. Buisztynsky, P.E., McGraw Hill Book Company, 1986. ' Handbook of Steel Drainage & Highway Conswcuon, American Iron and SIeeI Insumte, 1983. Manual of Standards of Erosion and Sediment Control ivleasures, Associauon of Bay Area Govemments, Jun 1981. S[ormwater Mansgement Water for the Puget Sound Basin, Washington State Department oi Ecology; The Technical Manual - Febn~ary 1992, Publication # 91-75. Water Quality Management Plan for U~e Lake Ta6ce Region, Vofume II, Handbook of Management Practices, Ta6ce Regional Planning Agency - November 1988. I Escao I ~ ( Conshuctiort Handbook 5- 54 March, 7993 v~~ ~ ~ ~ < •~ 5 F ._ ~ W p`, °~ O ~ ~ ti~ o `~ W ~ h CL T Q v 0 N JV N O U ia a 0 L a ~ a ¢ ~ a a Q V a ~ ~ ~ o o ~ 3°~ 3 a~i a~ c °~i + v ~ G ~ ..S V V H ~ ~ V p ~~ ~ ~~.. ~ O'L ~ ~ E E ~` ~ r O~ .s ' ' " C~ ~~.. C C V ~' ~ ~ O ~ G C ~ G L C = C y 0 ~ C ~~ W L 0y iS c3 C~ C Q = J~ C J~i ~ O" C d O ei V~ C O y ~' ~ M ~p p c 9 U U L ~ O O C C ~ C, C'V '~ O v~ o ~ ~.° =yj~ ~ 7 ca u ~3_. 9y ~o " c ` ' L ~ ~9o c ° ' u L~ Ca 3[..~ ea ~ ~ ~~ .odN ~ ~ N ~ ..€, c n 3€ y ~ ~ O~ O~ ~ y= s~s~ ~ ~ 0 0 9 '7 ° '~ O•_ u ~ ~ 1 ' ' ~ . r.A 3 3 ~ F ~: a'- ~ ~ oe'oe do~u ~mx~mca3 . ~. ycC °vi' U~U e~ R° cs ~ ^+ (V tV -+ G ~ H ~ ' u r ~ 3 V ~ ~ ~ C O . ~ ~ p `~ . C C ~ C V C ~ ~ ~i y~ y td N ~ ~ ~ ~? va 3 ~ ~' ~ " ~ 3 . A 3 ' L i N '~ "~J N ~ ~ ~ O .Yi G~i N V ConstrucGon Handbook 4- 36 Marc6, 1993 ~6C , ' ~~ c0 ~ ~ ~ + n 6. U ~ ' ~ ~ F ' ~ ~ ~ ~~ ~ ~ ' ' r ~ ~ r ~ ' ~ a - ~ a ~ G ~ ~ a? .'F C G ~. ? O ~ ( v, v. N y 3 c ~ ~oE 3 2 ~ ~ ~ ~ ~ .3 p G. , , ~ ~ p ` N ~' m d al ~ ~ ' c7' ~~ c N ~~n '~ ° ~u ~ n 'o o °~ 3 ~ m ~ a,.^ c o ~ ~ T o F Z {' a ~" ~.: O ~ ~ o ~.- .c ~ C.p c5^. `° o '~ ~ _ T ~ T V ~ J ~ ~ ~ C ~ u~i ' r~ ' ~1 N C y o ~„ ° .N ~ N ~ ~ .~(J ; ~ y ` . U - ~ ~ U V ~ ~ ~ ~ V y ~ ~ D . L ~ ~ ~ ~ ~ ~ _ ~ ~ O V f fn O O'~ `~3•7 T ~ ' CIl G C ' U ~ ~ 9 cD~ j oD v ~0 y ' v i ~ v~i a u~ ~.~ ,;, ~ 5r.~~~~ ~~ O= -° v ' D 53v ~ V c ~ ~c~ ~p Gl , N C c ~ r . 'J N O ..~'. D V T t~. V`n :1 . ~.ja C ~ R ~er N G . v`- -~'~`~~ yi ~ ~ U 2 '~~~ 2 O~n m.^3 .~ O 2 ~ Z V e~ i ~ y ~ ` .e~~~ ~ ao G ~ ~ dfG'V'~ v~i o~ ~~ . ~'~ ~ Ly ~ O CL c 'J . `fOO~O 0. O .I . O U K ~~d C N v~i ~Cwt ~N/ p, ~ g d` C~>V. y L p C,= H ~ O~~.. ~Y(~ .dy 2 yN ~N( Z.y~ ~ L ~: `~ C'i r C9 ~ O.~ ri ~ O p y CI Q : U ~ L(6 N ttl LE X q..P. w 3 ~'C'cF^ o UO U o L~UaLIr+ 7~v~ o. 3F `~F f-• F WF 3 a y -+ N ~ -+[V -~ -+ N[n . ~fVM -+ N cn ~ -.(y R > L G Q ~ ~ a - ¢ a ~ a W ai ~~ c c 3 ~ ~ ~ ~ ~ ~ y ° ~ ~ N ~ i~ ~ g '` ~ ~ u ` U'~ y , y o g. .~e - . ~ -W~ O q ~ ~, O ~ ~, 3 G 3 C y~J. y c~ a . ~~ ~L !n W 0" Y yQL'O ~v a `~ c ~ Cp '.~ = 'O ~ .pqp•- ~ ~ ' n " 61 ~A ` ~ ~~ 's ~F ~ 2 ?: V ~ E~ u ~ 3 V 63 ~ ~ ~ " 'Z CO . ~y .a ~ V H ' ~ U i . i~ Q .~ ~...~ 2. F~ ~ T " -~ V ~ i n U C~ `~ o o$~~ c, D m=~ ~ °°' o$ o~ .v° u,u ~ 6 U~.. ~.Da~ -' ~~ ~.-.~~..C~ 9 R~ ~ ~ v ~0 ~' ia~ y p A c~ 3 ~ u ~ c } N ~ .~ ~ ~ ~ F'' ~ ~? ~ q] oo d=~~ ~ ~ "j ` ~ c- e ' c L ° ' ~ 3 -~ u C ~ d['S V y ~ ~ " N ~ C'~ N ~(n " Ci y ~'~ 4.~ lH' ~ O N V~ N~ .1 .r y ~ oCi N U ~y V ~ Q y ~ 'J' 3~C O~ ~ ° p LL~ °~ ~ Y O yU=•'J G O T ° ° f ci~ ~J y ~ N N~?~ N OA N ~ U N N . O ~ 'O N O ~ . n . .; w' e cA ~ E vF °' u° a c i -~ = A ~ °a ~ o z y o " C a ° C ~ ~~• `~ a. : • C U c •~ 'qin w ~~ , g A rn F ~ ^+ tV .+f`7 ~+ .+ fVC~'i -+ -+fVt~i .+ . .-i .+ .+(V 09 H . d . ~ ~ ..~. ~ ~ V ~ U ~ y~ . N F e ~ ~ '~ : ~ u I U °1 a ~ ~ a ~ ~ , ~ ~ , , W. ~ .. $ Q W ~ ~ ~ ~ ~ .~r . d A a ~ . ~~ . y ~ y C V ~ ~ x ~ p L A ~ _ p O o i v - p ~ ~ . ~ G ~ ~ = 'a ~ Q 2S. . i Q 2'i ~ _ ° u a o ~ a v~ - E eo a0 '9 eu W 3 g a~ ~ ^ ~E . A tp ~ V G ' 2 C G F' O G ~ p - N ?2 > ~ O ~ L y 'D .y . C ~p J . j~ ~ d O ' ~ _ fi . ~ s ~ e~ ~ O ~ ~ c i ' s t a w F ~v a ~ > ~ a o a ~ ~ Construction Handbook 4-34 March, 1993 ~~ ' ' +- ' , ' , ' , ' ' , ' ~ ' , ' ' ~ ~ ~ a~ m C ~ .C ~ P. O' U V ~ .n f~ _n ti U H y a T O ^ y ~ ~ .. ~ y r . . F .O . L rj- ~ ~? _ O ~ a' ~ o `~ ~~E A c7 ~ a ~ ~ y c_o in o °~,' ` 3g. EyN~ °a ` ~ W c [~ y . ~ ..( .,h,( y y ,~3 N t'.1 C.1 L C C N N Q ~p = ~ ~ ~ 'y 7 T . ~ .~ N V 6 = ~ C "'~ '-~ ~ U O ~ C.'~ tG'~ ' `6 -c5 a~ m.. ac'i .-: > ~?~ ~ `~f 3 ° o ``~' 3~o~UD3wti~° ~ O~tn «S ~ V hl ~ > O a Q ~ ~ a Q ~ x ~ W a L T O~ C9 ~ ~o ~. L ~' L Td ~ 3 ~ v~ ~ ` ~y `~ ~~ a~ ~o _ ' , .,, 9 ~ a i r ~ 3 V • a > C O S O.` ~ O C G . T'~ ~"' C> e .°. ~, ~ T ~ 3~'y .n C ^ 7 O O v 3 C N ` G OA O y~'r'J' O O C O F y W y~ 5 ~-+ y ~ 3~'O ~ a ~ ~°o . Y u~oa~='~ ~' ~a:°. ~AE=-7'-0 ' 3 9 u~° 'O 3 , o~ W Z y d ~ "" o~eo ~c ° v`~ 3~ ~ a° ?~o3 a~ - ~3~~. c~„r.o A~v;'. c'=o~`~~ a~? a~ . ~n3 a o, .c~~ a``d ~o- ..._ t 0.3 `°N r ~ a,"v, a°:m 3a3 ~ .~o ~ h ` y ... ~ O lO ~ F V _y ~ C•~ C ~p~ ~ . y . N C• N y ~ OO ~ IJ - ~ ~ R ~~ ~ ~ G ~ ~ ~ ~C ~ ~ ~ ' C E ~ g O ~d 3 J CJ N ~ 1.~ S' ~ ~ ~ Y ~~ 9 ~ C U O y~ ~ v • Q :' c ~i , °~o D JSc a °J °' 3 e0~ cc~.,3p ~ a ° ~ $ ° 9 ~. ~ y ~' "'' o oE v° y.on ~ n . ~ pcy . c ~c i n ~e `~y ' . n ~ l,a voa ~~ '0~ F ~ C C 3 ~j ... .'~.'OCvh ~ L ~ . 3° ~+ G 0 O~ ~ `n ~ O=O ~ ~y U d ~~ T N ~~~ y c0 ~•~ ~ D- ~~ ca ~y ~ y.n . cQ '~ ~~ C ~CC 7 j!~ ~ N~vi m N'O ~ °~ ~ ~ ~ ~ m> ~ ~°~~3~ a3a~C .dZ`'a, 3~°F' ~ N R °-~~o v3' ' ~ R6o ~.Eo ~ C ~~ U C U V n N~ Q I U N ~~~ A ~ ~. . r r G OD Ci ~ ' Vl L t~ ~0 W W .O V U '~ C A --~ f`I fV t~i -~ c`1 ~ ~ -+C`1 a L > L Y~ 'i'0 ~ Q ~ . (TC ~ F ; _ „ ti 6 E 3 ~ - C .O ~ t~ ~ ~ N ~ ' E" a ~ ~ ~o ~o a C 'C p ~S' y C ~ ~O V ~ ~ . ~ e . ~ ` t 05 05 y ~ w (7 0 o ' g a~ H ~L ~ v .a°: ~ .8 ~ . u j 00 v~ a~ w .'f~CG ~ td ~n ~.~ ' C ..~. ~ ~ ° vH ~° W °° ' °~C ' ' V ~L 0 t) 3 Ev - '- ~ > O~ ~ C ui ~ t~ °C en ~ e`y ~7 ~~ C ~ U E ~ ro~~ `~R u ~ `~~ ~,~ p oC A 8 ; ~ " .. ..~ ~ • v a.~ U • 3 v ~° . d N '~ c. Gao, °~ ~ ~ ~ ~ z o °~ 3 ~ o a~ '~ ' ~ E ~ ~ a~ J ~ ~ - , V ~J ~ C Z ~ U v~ 9 4 x ~/] ~ s ] w ~ ConsfrucGon AandUook 4- 33 March, 1993 a(p a ~ `~'' u ~: ~ . a ° ~ ^v N V ~,y a " ~ ~ ~~ a= o . i' `" 0 z L ~ 3 '' N = ' >~~..`~i W 0. a~ c> ~~oa~~~ c~~o Q C3 ~ ^ y G. v~ y G ~ ~ 9 ~ - V] O W c .°_ ' - ~ ' - ~ ° y? 0 3~ [~i N A ~ . 'n ~ G O : G a~ ~ ~ L r U ~ ~ ~ > ~ O S r r O 7= . ~ y U F ~ 0 O V ~ `~~ Tg ^ ...1 ~ ~TN a~ .- 0.'Ll O O a> l,.~ ~V~>E~ ~ fV N F 7 n 0 ~ ~ ~ a ~ ~ ~ a Q U ,y W W N ~ C O U 'U u O ~~~ T ~ ° ~ N N y h C ° t3~ . ~ O•. -r (~ • :o c g . 'Q ~ 0 3 E. _.° o .J " S ~ o ,o ~ ~... '~ o ~ C 3 ,y ~ ~ € ~ ~ 3 .3 ~ ~ y 'C W 0. v .. c`~ ~ 3 ~ `' w o ~y o ~ +° ~ ~ :° ~ 'c ° ~ C c `i~' ° "~ F- 0 ' > c ° ° ° ` z y ~ u . ~a~ a i G c ~ :p ^ o00 ' ' ~ ° '' . ~ 6 v ' w a ~ ~ ~ ~ ~ O C ~ T~" 'O ~ ~ G C ~ F `3 ~ F "" a8 ~ ^ N ~r~ d l 0 C h . L'~ . O ~t " . c~ e i ~[a V~ ' C ~ '_ ~ ca O T 4 ~ a> C'~C CO.~ _"~ q ~+ :: ~ o o v ~p ~ ~ T" ~ ,n o~ N.n ,n w n? ... v v~ 3 c. e c~ -cY3 '-w d=~ A ~ t0 y V ~ U~ ~~ .n ,> >€ u h 9 N~ ~~'C O ~~Q~ C 6~ t'3 ~.. t. 6 _' ~ ~ L .~ ~ q N G 6~ N N V V G s C EJ 0 ~+ ~.~ N C QyO ~ C ~ 0y0 O N ~ N G~ " ~D Vl Vl U y S c6 ~~ {]r 'J' o'V TS ° ~ ~ . ° ~, a . ~ c ~9 ~ ~ ~ :o ~.r ~. . U 4~:~ ~ y ~~ y o a fh dR~'V N ~ ~.~ ~ J SjiO 6~'~ VJ N `v~, ~ y F~ ~E 0• R ~ a V x.=_¢ o xca o V ]>>ca a s ~ o aca ~A¢~ s ~ vu i. ,:.~ a C m -~ N ~+ N N M ~ N ~+ N fn ~+ ~+ N Y V ~ ~A Y ~ N r'~. ' . ~ ~ $~ c 3 ~ C C C y . S ~ - . ~ ~ ~ G Q . ` ~ K ^ ~ ~ . V C e N c 3 .,~ ~ g ~ a c' ~ ~ ~N c ~ '~~' ~ oA ~ m ~ ~ ~ O L i V ''J~' C~ y..~ ~~ . C ~~ V p ' U .. y C O.,i ;~ C " ~~ N C ~F ~C ~ N m ~ h o y ha E~ c 3 .p V O _ "'~'' O 9 a 'd a, 't c ^ D v° G ~ ~3 ~oA ~ O U '' g 9c 0 C .no ' ~ H ~ . ~c C 0 0 ~~ 3 E~ (a ~ ~ ~y . N `~ ° ^ :_ o . 'o .p y V ~ b ' ` ' ~ c~ ~ ' ~ y W a i ~ e O oE ~ ~c 3 J .. . ^ p 0 ~ N ,r ~e - ea t ~ ~a C> cY. .Z v S c°~ rn V z U c n~. rS I Construction Handbook '. 4- 32 Marc6, 1993 `' . ~ L ' ' ^ ~ N . , N N ~~ a ~ c ~ . 'd ~ ' ~ F , ' ~ , ' ' ~ ~ ' ' ~ ' ~ ~ 3 I 1, ~ G r"' ~ y U F ' ~ ~ n C C -.° . ~ '~ ~ o ~ ' o. W 0. ~ 3 Y ~a ~ c~ T ~~. G `° ~ " Y ' ~ ~ " ° a~ C/] O - N O o _ C.f r ~ o ~ r ~ °~ CL' " . S. e, ~ ~ y L `~' > °-~ 0~.3 ~ > oa 0 ~o . „ v~ ~ E_ . 55 G ~ G ~ ' x ~ N N R ~ ~ ._ O cVj E 'C~ 'O a~ "' O~ V. 'O ~ N N N N ~. O td ~~ O ~y ~ ~~ ~ a ~ `~ES.- L 4`~ E~i O A aia 3~9~ ~ 3a~~ ~--~ N ~-+ N e~t ~ N ~ ~ L a a g . ~ c I J .~.. ~ o U 7 cx W ~ ~ ~ g ~ ,,. ~ ° „ ~• m c "~ ~ c~C ;o ~ a ~en an c c ~c 9 . u ~ y d ~ ~ i 0 0 ~ ~ '` ^v L ~ . v _ °`. 93 a~ ~ ~ ° E F ~. ,~c ~ °€ ~ ~~ . ' ' ) ~: ~ ~ ~ ~ ~' C c V 5 . '1 ~ .. G ~ v > ~ ~ C E N ~ j~ N N-' d ~ - ~ ~' O _ ' . ~~ ~' ~ W 0. U v} ~3 R G td L O O 4 . N ,~ .D O vi y~ . C . yL N 3 ~ ~~g 6R fn 6~ ~ .z o Y ". `' ~ n o 4 >3td .~ o~ ~ a. 5 j~.m ~o ~ ~o . ~. n m S. , 8. p °~ ~vo o~E G c ~~._ ~o ~E ca~ o ~ H ~ p ~ A ~ e O 'a `.~ v~ rJ N ~fn~ trd-, ~vE .sa~ c_r o O p ~Te°- 'O N C as ~ ~~ ` N r~ii o~e ~. O i,3 E= O T! .~E=: d y3 y o '?~-ena. 'cao ~ ~~ •. m xb °' ~~^ cd-'~ ~ v c dH. ~ ~ o~O~..eaC.~.n~y=o ~ ~_~.. o, ~ 3D o . y mE ° 3.0`~ ~ 3 `n_ 3° `n` ' m ~ C D w C j i W ~ E w c N °J ~ o. 'v U~ 'v vi .. ~~ ~ ~~ p~~ p~ ~ i .-. ~ Q ~ A ~ OUf"~ ~GC~> °3 w . w d N C~ 3 m H ~~~ ~ `~ y 'oo~ °~." LO. ti '6g'u Ld ~ E - . c noa U o ~ 2 S ' VJ N ^ / 1 Ir E/ Y U V VI ~A ~~O(A 3c °.Qo ~ ~ ~ N ~; ~z~ .. Cl fV -+cV -+cV~ t~i -~N ~ R L C • ~ . C N~ oo ~ y ~ a u~ ~+ F c ~. ~ ~ y $ ~ . ' ; ° ~ ~ ~[ aC ~ ~ F a e~ 1°' ~ ° ~' ° g o ~ . ~. ~ m c ~ ~ ~ ~ ~a ~ :3 ' ~ 0 ~ > _ ! 7 { ~ ~ d ~-~ 'O ~ m3 C ~ O ~ W p y ~ . . y ~ ~n C ~ ~ ~ ~ ea `~ Do.. y 7 C ~ O O Q ~ CL ~ 6 O 7- ~O . q p, . O ~ V « y C ~. ~ ~n •~ - r7 4.~+. ~'p U - " > U G ' g y a°~ eo ' E ~ s ' ~ (j ~o c O ~~ ~ ai i~ ~ c ~ ~ ~ 3 c A ~ .~ H O ~ ~, ~ O d :°c~ QEp ~"l ~ m °~ ~ ~ ~ ~ ~ 3 V °~"~ d g° a~~ -` ° c i -~° ~ = ~ R~ i v z~ m_:~ ~ n3 v°~y° ii ~ u". 3~? <a Construction Handbook 4- 31 Marc6, 1993 ~- ' ' ' - j ' . ~ ' N rn ~ _. ~ .D ' ~ ~ N ' W Q ~ ~ - ¢ 4 ' za (li py W J ~ ' ¢ C QU ~ C O ~' ' ~ q a° 1 ~ ' W ~ _~ o h ~. C [?-~ O ' w n. a a ~z ' H C ~ O a~ ' N. ~ ~ ~ jV Q c ' F~ E 0 ~ w b ~ G O ~ ~... ' Q ' 1- ~1 , H o. y N ' ~ n `, `,~ ~ ~ H ~ ~ ~ ~ a '~ ~ E ~ c , n L ~ ~' ~ C O 3 ~ C ~ ~ a ~ o 9 ~Q ~ ' O X 0 N c~ J L~ . ~ V c ~ ~ ro o ~ 3 ~ ~ u ~ y ~ ~ O ~ N a C ~ ~ C ~ ~ n N ~ G`, y V n L ?: w ~ ~, a ; 4 3~~ c o N ~ 3 Q' ~ V ~D ~ L 9 G C ~ R 4"' L ~. ~L ~en C ~ h y C N C ~ G y p ~ p~ 'y m r' ° ~ cO o v ~ O o E ~ . L ~ L E O ~ '~-, ~V.. L: y > ~ ~ '~ o E L0 v W ~r~ (~ C V d G~ y G o G ~ ~a~ e ~~:; ~ . w CC i 9 O. a~ .U a> '" ~ ~ fn ~' y ~ 3~~g.~e ~ ~~ L N y•.. y~ y ~ F " ~o ^ o ~ = oa ao H• . ~ ~°~°'~~o r ~p ca C a. y ~.. . r3~E~' , ~~ ?? ~3-;.~ ~ u p ~^ ~ s~ ia 3`c3 3 ,5 ~ v°~i ~ o ~+ ~ ~ C y p~ ~ d,7 OA?~ ~ ~ y~ ~' ' Y' W R+ ~ ~ N R . U ~ v i ~J" .C 8Q s ; ~ ~~ 3~a 5.8.8. 3< x~ "~' q ~zd AC] ~ax.° _ _ ~-. w ¢a ~ ~onstruction HanJbook ,.: O v w ~ ~ . , ` c ~ ~ .~' c ~ ~ .. _ ~ v ? .. a~ ~ Z ~'_ y €, g ~ h ~ 5 A ~v P °_~ y~4 . y3 R y - Q tn o o c E -°co 2°N' o ~ n ,n v` '~ ' ~a ° = v ~ Ga ~3 °' '=go ~ , °y3 °: ~ 3 'J' S ~ T , , "~ G> N ~ ? ' ~ a~ - > > o :? X o' ~~n' N ° _ . ~ o _ ` ='y E.a , ~,,~ o = o a~ o V °' V~~ 3 ~a.. a ~ ~a~ a o ~ ~ ~F ~,,° a~ x ~ F ~ ~ a F ~ ~ii. ~c ~N -+Nri 3~[V ~-+ ' ~ > 0 L a ~ . C Q ~ a a U ~ w ~ c' N ~ 9 C y ~J N O ~ ~ y ^ C °' ~ ... T, N ir ~ C N r p . . C °' . . ~,~ .-+ 3 V1 •° ~'' c`~lv :n $, ~ti J' ° ~ ~ ~ `~ ~ -~ a~ eoc3 c ~ '~ ~' o _ W~+ 3 y L3 ~ ~f.; 3 d~ h~ ua~ y m 3 € N'`°N e o . yo ~ y v ~ ~+ y y N ~+ 6 N ~ ~3 ~ VI .7~ c C e ~ ~ ' C ~o c ~ ~ Zc a ~-'O ~ ~ N Z ~ ~ '~ ~ a~ `~ o ~ '/~ OO U 6g > > c n "' = ai `e ~ g ai = ~ a a i ' ~' o ~O ~ YJ. E ° ~ ~ . .~i. " ~ n~ ' C„~. G . {C ~, yN ~~ L O ._ ~2 ~ ~ ~O ~~N~ ~.Q '~O ~~ V= i 4 9 ~~ ~N ~..r CJ ~ N :.n y . iC /~ N ~_~ G1 (~ V LO 'Z ~ n ~ V N T - V ` j N ,~ °~ v~i .~ g i~ . v~i C' C~' ~~ ° Y ~+ G N L ~O ~ U•= . T o aa ~~ v~ e~~3 `~ a~ y h > o h - ~ E~ N °~ N ~~ ~ aA xo~.;~ ~.i~o ~.a a o O ~ ~3v~ O ~u ~~ '9 ~ A .: cV .: (V Hi ~ ..i (V ~ ..i ~i ..i ri oi . ~a .. cv s E d ~ - ~ ~ . ~ ': . F r e v n' .] > = . L ~ ~ 3 ~ U ~v ~p 'Q ~ ~ ~ o F ' W y `,'x ..~ . C ~ 6~ (' J ~ N ` p ~ ~ ~D ^ ` N ~ . N~ C a ~ 3 $ ~ ~ ~ ~ y 3 ~ _ o e0V! eD a x y .'0 3 ~ 0 '~O e ° y o ~ ~ 5 ~i d 'a :o a a U ~ ' ~ ~ ~ ~ '~ ~ a'~i 3 o a a`~ N- Q L a a . m ' U e . c U Y vai G ~ Cx = ~ y . ~ „ ~, ~ K .a ~ E ~ =y ~~ C7 w W a n. W a m c U s 5 4-30 ~ Mazc6, 1993 ~ ' ' ~ ~ ' ' ' ' ~ ' ' ' , ' .. 1 t , ' ' ' ACTIVITY: EMPlOYEE/SUBCONTRACTOR TRAINING (Continue) Consider posang ~he quick reference table around the job site or in tbe on-site office trailer to reinforce training. Train employeelsubconuactors in standard operating procedures and spill cleanup techniques described in tt~e fact s6eets.. Employee/subconrractocs trained in spill containment and cleanup should be present during the loading/ uNOading and bandling of materials. Personne} who use peslicides should be trained in tl~eir use. T7~e Calitomia Depaztrnent of Pesticide Regulation and county agriculnual commissioners license pesticide dealers, certify pesticide applicators, and conduct on-site . inspections. - Proper edupuon o[ off-site conUactors is often overlookeA. T'he conscienlious efforts of well Vained emp-oyee/ _ subconiractors can be los[ by unlrnowing off-site conUactors, so make sure they aze well informed about what they are ezpected to do on-site. I CA40 1) Construction Handbook 4- 29 Marc6, 1993 ~~ , ~ ACTIVITY: EMPLOYEFJSUBCONTRACTOR TRAINING ' ' ' ' ' , Objectives Houselroeping Precfices Contain Wesfe Aiinimiza Disturi~ed Areas Stabilize Distur6ed Areas Protect SlapeslChannels Controf Site Perimeter Contro! Intemal Erasion DESCRIPTION ' Fmployee/subcontractor training, like maintenance or a piece of equipmen4 is not so much a best management practice as it is a method by which to implement BMPs. This fact sheet 6ighlig6ts tbe importance of vaining and of integrating the elements of employeelsubcontractor training from tl~e individual soucce controls into a comprehensive training program as part of a company's Stnrm Water Polluuon Prevenuon Plan (SWPPP). 'Ibe specific employeeJsubcontiactor tcaining aspects of each of the source controls aze 6ig61ighted in the individual fact sheets. The foeus oF this fact sheet is moro general, and indudes tLe overall objectives and approach fa asaiuing emp]oyee/subconrractor training in storm water polludon prevention Accordingly, ihe organization of this fact sheet differs somewhat from tt~e ot6er fatt s6eecs in t6is chapter. , ' 1 ' ' OBJECTIVF.S _ ~ploy,ee/subcontraaor training should be based on four objectives: ~ ~• Promote a clear idena£cation and understanding of tbe problem, including activities wiW tbe potendal to pollute . ,-( smrm water, Identit'y soluuons (BMPs); Promote empioyee/subcontractnr ownecship of the problems and the solutions; and Integnte employeeJsubconuacwr feedbxk into vaining and BMP implementation. APPROACH • Integcate vaining tegarding storm water quality management witL euisting tiaining programs tbat may be requiced for your business by aher tegulafions such as: the Illness and Injury Prevendon Progrem (IIPP) (SB 198) (Califomia Code of Regulations Tide 8, Section 3203), the Hazardous Wastc Operations and Hmergrncy Respocise . (HAZWOPER) standard (29 CFR 1910.120), the 3pi11 Prevention Control and Counte~measurc (3PCC7 Plan (40 CFR 112), and the Hazardous Materials Management Plan (Business Plan) (Califomia Healt6 and Safety Code, Section 6.95). . ' B~sNess~s, pazticularly su~aller ones that may not be regulated by Fedecal, State, or loca! iegula6ons, may use We information in this Handbook w develop a training program to reduce theff potentiat to pollute stoim water. ~ Use the quick tcference on dispc~sal a]temazives (Table 42) ro train employeelsubcontrdctors ia proper and consisrent methods for disposai. ' ' ' CA40 ~ ~ ~St Managemen Practices ~ ConstrucUon Handbook 4- 28 March, 1993 ~p~ , , ~ ~ 1 ~- ~ ~ 1 ~ ' ' ' .. ' ' , ' ' ' Additional Information - sed~ment Bas~~ ~ ~ ._ ~ ~ TOP VIEW ~ ~ - ~ ~ ~raouo¢r ~.u.o " DETEHiION TAff~ 21 TO 4p Iq{1R5 ~'--- SmMEHT STORAGE VOLUME. ~ ~ ~ ~0F'K~ ~~~T . ~ uo 111L~ ~ro0[ _~_Q-_~__-__~~~ ___--- __ __ MlOi . . !E'fTI.M OPIN z rt. r.a oern~ :5 _ ' _- - - _ _ - __ _ _ _ - _ _ _ _ _ .. 2 . lEtwdf SiauL -~ S' NGX . ~ n_ wc wm ~ srua~ oin~t ~i niotm ' . . . ~ ~mucra sv¢t . ' . . rwa~+a ~ oeian ' . DETENTION TIME: 24 TO 40 HOURS SIOE VIEW .rn-am ccu~s SEDEMENT STORAGE VOLUME: 67 CU. YD. PER ACRE . ~ TEMPORARY SEDIMENT BASIN I ESC56 11 e.. j w.~av. ~~" Construction Handbook 5- 95 March, 1993 `Fj~ ' ' `i ' ' ' ~ ' ' ' , ' ... ' 1 ~ Additional information - Sediment Basin ~ A Cutrent Assessment of Urban Best Management Pracuces: Techniques for Reducing Nonpoint Soucce Pollution in the Coastal Zones, Metropolitan Washington Council of Govemments, Mazch, 1992. Best Management Practices and Erosion Control Manual for Cooswction Sites, Flood Control District of Maricopa Coimty, Rough Draft - July 1992. Draft - Sedimenta6on and Erosion Control, An Inventory of Cutrent Praaices, U.S.E.P.A., April, 1990. Envuonmental Cri~e:ia Manual, City of Austin, Tezas. Guidl'mes for the Design and Construction of SmaIl Embanlrment Dams, Division of Safety of Dams, Califomia Depart- ment of Water Resources, March 1986. Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Goveroments, Jun 1981. Proposed Guidance Specifying Mnangement Measures for Sources of Nonpoint Pollution in Coastal Water, Work Group Working Paper, USEPA, April, 1992. Stormwa[er Management Water for We Puget Sound Bacin, Was6ing[on State Depanment of Ecology,'Ibe Technical Manual - Febtuazy 1992, Publication # 91-75. Water Qua]ity Management Plan for We Lake Tahce Region, Volume II, Handbook of Management Pcactices, Talice Regional Pl~u~ing Agency - November t988. Constructian Handbook 5-94 ESC56 ~ r..~..,.. Mazch, 1993 `~3 , , ' t- ~ ~ ' Additional Information - Sediment Basin 7Le senJing zone vol~e is determined by the following equation: (V) = 1.2(SD)Q 1 VSED Q= uSED =~ ~~1°B ~elocity of the design soil particle. 'Ihe design pazticle chosen is medium sil[ (D.02mm). This hac a settling velocity (VS~) of 0.00096 h/sec. As a general ivle i[ will not be nece.s.sary to design for a panicle of size less than 0.02 muy especially since t6e surface area requirement increases dramatically for smaller partide sizes. For ezample, a design particle of 0.01 mm requices about Wree times t6e surface area of 0.02 mm. No~e also that choosing Vsgp of 0.0009C fdsec equates to a surface area (SA) of 1250 sq. f~ per cfs of inflow. ~ , ' ~ , ' ' SD = design intlow based on the peak discharge from a specified design stam (e.g., a 2-year, : duration design srorm evecn) from tt~e tnbutary drainage azea as computed using ~he c required by tLe local flood control agency. Prrnide a atinimum of 67 cubic yazds of volume per acre of clrainage if a design storm is no[ speciHeA. , senling depth, which should be az least 2 ft„ and no s6allower than the average distance from t1~e inlet to the ouflet of the pond (L) divided by 200 (i.e., SD > LR00). Total sed~ent basin volume and dimension are de~ermined as ouilined below: a. b. c. d. e. f. 'Ibe details shown in the attac6ed figure may be useful in designing the sediment basin. Derermine basia geomerry for the sediment storage volume calculated above using aminimum of 1 ft depth and 3:1 sid slopes from Ihe bottom of the basin. Nae, the basin bonom is level. Extend the basin side slopes (at 3:1 maz.) as necessary to obtain the settling zoce volume as detecmined above. Adjust the geometry of t6e basin to effectively combine ~he setUing zwe volume and sediment stmage volumes whi; preserving the depth and side slope cri[eria Provide an emergency spillway wiUt a ctest elevatioa one foot above the top of the riser pipe. 'ILe ra[io betweea the basin length and width of the pond should either be greater than 6:1, or baffles should be installed to prevent short-circuifing. T.imi ati[mc . . Sediment traps and ponds must be installed only withm the property limits. Failuie of Ihe strucwre must not result in loss of life, damage rohomes orbuildings, orinterruptiou of use or service ofpublic roads or uulities. ALso, sediment traps ~d ponds are a[ttac[ive [o cLi]dten and can be very dangerous. Local ordinances iegard'mg healtL and safety mus[ be adheced to. 7f fencing of the pond is required, ihe rype of fence and its location shaIl be s6own in tLe SWPPP and in tLe consvuction speciscacions. • Generally, temporary sedimentaflon ponds are limited to drainage of 5 acru or more, • Sedimwtpondsmaybecapabteoftrappingsmallersedimentparticlesif~ditionaldetentiontimeisprovided. However, they are most effecfive whea used in oonjimction witL other BMPs sucL as seeding or mulching. • Ponds may become an "attcactive nuisance" and care must be taken to adheie to all safety precfices_ • Sediment ponds designed xcading to tLis handbook aze only prac6caDy effec6ve in removing sediment down ro about the medium silt size fiaction. Sediment-laden nmoH witL smaller size fractions (fine s~7t and clay) will pass througL untrcated empl~asizing the need to stabilize tLe soit quickly. ~ ESC5G ~~ 1 ~ Consttuc6on Handbook 5 - 93 March, 1993 ~cy~ , , ~ ~ ' ' ' ' , ; , , ' ' ' ~ '.-~ ' ~ - Additional Information - sediment aas~n ~ A sediment basin is a controlled storm water telease swctwe fom~ed by excavation or by conswcting an embant~ent of compacted soil across a drainageway, or other suitable Iocation. Its purpose is to collea and store sediment from sites cleared andlor graded during construction or for ex[ended periods of time before reestablishment of pemianent vegetation and/or conswctionofpermanentdcainageswc[ures. Itisinteudedlntrapsediuientbeforei[leavesibeconswctionsiie. Thebasin is a tempcxary measure (with a design life of 12 to 18 months) and is to be mainlained until tLe si[e area is permanently protected against erosion or a permanent deren6on basin is conswcted. Sedimentaaon basins are suitable for nearly all types of consnuction projecLS. Whenevet possible, construct the sedimen- tation basins before clearing and grading work begins. Basins should be located at ihe stormwater ouUet from the site, but not in any nahua! or ~mdisturbed stream. A typical application would include temporary dikes, pipes, and/or channels to divert runotf to the basin inlet Many developmentptojects in Califomia will be required by ]ocal ordinances to provide a s[om~ water detention basin for post-cons Wctiou tlood control, desiltation, orstotm water polludon control. A temporary sedimentbasin may be constructed by roug6 grading the post-consttuc[ion contrvl basins early in the projecL Sedimentbazins trap 70-80 percent of tl~e sediment wbich flows into them if desigoed accmding ro this handbook. T6erefore, ihey should be used in conjunction with erosion con WI practices such as tempordry seeding, mulching, dive:sioo dikes, etc., to reduce We amount of sediment tlowing into the basin. Ins al ati~ /Anp ip ion .rit ria Planning: To improve the e[fecdveness of t6e basin, it s6ould be located to in~ptnmoff from t6e ]argest possibfe amoun[ ofdisturbed azea T'he best locations are generally )ow areas below disturbed areas. Diainage inro the basin can be improved by We use of divasion dikes and ditc6es. 'I7~e basin mus[ no[ be located in a stream but should be located to vap sediment-laden runoff I~jp~ il enters ~6e stream. TLe basin should ~ be ]ocated where its failine would result in the loss of life or intenvption of ~Le use or service of public utilities or roads. . Design: • 71~e sedimeutation basin volume consists of two zones: - The sediment stmage zone (az least 1 foot in depth). A setUing wne at least 2 fee[ in depth. The sedimenration basin may be formed by partial expvatioa andlor by wnstruction of a compactcd embankmen~ It may have oce or more inflow points. A securetyanchoredriserpipe with an anti-seeprnllaris theprincipal oufley aloog with an emergency overflow spillway: Asolidriserpipewithtwo 1-inchdiameterdewateirog Loles locatedatt6etopof thesedimentstordgevol~eonopposite sides of theriserpSpe usuallyprovides sufficientdetention time forbasins draining about 10 aaes. Rock, rip-rap, oro~her suitable outlet protection is pcovided to reduce erosion az t6e riser pipe outlet Senling Zone Volume (:onstruction Handbook 5-92 March, 1993 `~ BM P: SEDIMENT BASIN (Continue) LIMITATIONS • The bazin should have shallow side slopes (minim~ 4:1) or be tenced to prevent drowning. • Sites with very fine sediments (fine silt and clay) may require longer detention tiuies for effective sedimen[ iemoval. • Basins in excess of 25 feet height and/or an impounding qpacity of 50 ac. ft must obtain approval from Division of Safety of I1ams. • Standing wacer may cause mosquito; or other pesu io breed. • Basins in ezcess of cerrain depth and storage vol~e criteria must meet State Division of Safety of Dams (DSOD) and local safety requuements. ConstrucGon Handbook 5 - 91 ; ESC56 ~ ~ ) ~ March, 1993 ~dp , ' ., ' - ' '` , ' ' , ' , 1 ' ' ' ' , ~ ' -~ , BMP: SEDIMENTBASIN objactives 1 Nousekeeping Prac6ces ~ Contain Waste Minimize Disturbed Areas - Stebelize DisNrbed Areas ~ ' . . . , ~ Protect Slopes~Channels - . ~ isc1JHL;~i ..~~v . . Control Sffe Perimeter ~ j j ~ ~, _ ~_ ~ Conbol lntemal Erosion GENERAL DEFINITION Targeted Poll~itants A pcrod created by ezcavation or constructing an emban}~ent, and designed to retain or detain tunoff sufficiendy to allow ezcessive sediment to senle. ~~~~~~ ~ Nutrienta SUTTABLE APPLICATIONS 0 Toxic Materiels At the ouUet of all disturbed watershed 10 azxes or larger. A[ the ouUet of smaller disuubed watershedc, as necessary. ~ Oi! b Grease Where post conswction detention basins will be located. 0 Fbafeble Materis/s SLould be used in association ivith dikes, temporary channels, and pipes used tn divert Q- Other Conativctan disturbed areas into We basin and undisu~rbed areas around We basin. W~te INSTALLATION/APPLICATION ~ Uks/ytoHsvs Construct befo~e clearing and grading work begius. s~~lncant fmpset ' • Do ~ locate in a sVeam. . ~ Probabls LoM or • All basin si[es s6ould be located wLere failure of the embanl~ent would not cause loss unknown Impxi of lif / d e property amage. Large basins are subject to state/local dam safety requirements, ~ ~mplsmentstion Sec:urely anchor and install an anti- collar on iLc ontlet ~ ~P P P~riser, ~d provide an Requirements emergency spillway forpassing major floods (see locai flood control agency). Q CepNe! Costa 7Le basin volume should be sized to capuuenmoff from a 2-year 24-hour storm or other , , appmpriate design storms specified by ihe local agency. A detendon time of 24 w40hours Q 06M Costs should allow 70 to 80 perceat_of sedimeot to se[tle. ~ MeintenencB • Tbe basin vol~e consists of two zooes: Q Tiaining - A sediment suttage zone az least 1 foot deep, ~ Suit bilit / - A setUing zone at least2 feet deep. e y or 'Ihe leogth to sectling aeptb ratio (I.~sD) shoola be less than 200. Sbpes >5% 'Ihe length to width ratio s6ouidbe grater than 6:1. abafIIes arecequired wprevent short circuiting. REQUIRF7KENTS - • ~~~ ~ Hi h 0 low - Inspact weeki and after e h i g y ra ac n. - ~o,~~~~wb~~~~,~s~~g~Z~~~~,. Cost Averegeannualcostforinstallation~dmaintenance(2yearusefullife, ESC56 source: EPA 1992) , - Basin less than 50,000 ft3: 50.40 per R3 (5700per dtainage aae) - Basin size greata than 50 000 R3 20 $0 3 . , : . per ft ($350 per drainage aae) B@St Managemen PrdCUCes Lonstruction Handbook 5-90 March, 1993 ~1, , ' . ~` 3. ' 4. 5. ~ 6. ' , , ' , ~ ~ t ' ' ' Additional Information - sediment rraP 7. 8. 'Ibe vap is removed and the area stabilizeA wLea tbe upslope diainage area has been properly stabilized. All cut-and-fill slopes should be 3:1 or flatter. When a riser is used, all pipe joinrs must be watenighL W6en ariser is used, at leasc the top two-thirds of the riser shall beperforated with 12-inch diameierholes spaced 8 inches vertically and 10 to 12 inches horizontally. (See Sediment Basin, ESC56) W6en an eartp orstone outlet is used, the outlet c[estelevaLion s6ould be at leas[ 1 footbelow the topof [he embanl~ent Wtsen a crus6ed stone ouUet is used, the crushed stone used in the oudet should meet AASHT'O M43, size No. 2 or ?A, oritsequivalen[suchasMSHANo.2. Gravelmeetingtheabovegradationmaybeusedifcnuhedstoneisno[available. Bes[ Managemen[ Pracrices and Erosion Controt Manual for Constcuction Sites, Flood Control District of Ivlaricopa Cotmty, Roug6 Ihaft - July 1992. __ "IhaR - Sedimentation and Frosion Control, An Inventory of Curzent Pracuces", U.S.E.P.A., April, 1990. "Environmental Criteria Manual", City of Austin, Tezas. Manual of Standards of Erosion and Sediment Control Mea'sures, Association of Bay Area Govemments, June 1981. Proposed Guidance Specifying Management Measures for Sources of NonpoinCPollution in Coastal Waters, Work Group Worldng Paper, USEPA, April, 1992. Stormwater Management Water for We Puge[ Sound Basin, Washingtoo State Department of Ecology,'ILe Technical Manual - February 1992,.Publication # 91-75. Water Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regionat Planning Ageocy - November 1988. ~ ESC55 ~~ ~ Cotuh~uction Aandbook 5- 89 Marc6, 1993 `~Qj ' , .-_ ~ ' ' ' ' ' `~ , ' , ~ , ' ' '~ Addifional Information - sed~ment Trap. A sediment vap is a small temporary ponding area, usually with a gravel outlet, formed by excavauon andlor by coostiucting an earthen embanla~en[. lts purpose is to collect and store sediment from sites cleared and/or graded during consWCtiou. It is intended for use on su~all drainage areas, with no unusual drainage feahues, and projecteA for a quick build-out time. It s6ould ffilp in removing coarse sediment from rvnoff. The trap is a}~,~ymeasure with a design life of approzimately 6 months, and'u to be maintained until ~he site area is permar~ently protected against erosion by vegetauon and/or struclures. q~lintion Crireria Planning: Sediment vaps should be used only fa small dtainage areas. If the convibuting drainage area is greater than 5 acres, to Sediment Basins (ST8), or subdivide the ca[chment area mto smaller drainage basins. Sediment usually must be removed hom ihe tiap after eacb raiofall event Tl~e S WPPP should detail6ow this sediment is to be disposed of, such as for in till areas on-site, or removal tn an approved oCf-site dump. Sediment vaps used as a perimeter control sbould be mstalled before any land disuubance takes place in the drainage area Sediment traps are usually small enoug6 that a failure of the swcuue would not result in a loss of life, damage to 6ome buildings, or intetxuption in ihe use of public roads or utilities. Also, xdimeot traps are aztractive tn children and ran dangerous. T7~e following recommendations should be implemented ro reduce risks. 1. Install continuous fencing around the sediment trap or pond. Consul[ local ord"mances regazding requirements for maimaining bealth and safety. 2. Restrict bazin side slopes w 3:1 or tlat~er. Design: Sediment trap size depends on the type of soil, size of We drainage area, and desired sedimeut iemoval efficiency (see Sedimrntation Basin ESC56). As a rule of th~li, the larga We basin volimme the greater the sediment removal efficiwcy: Sizing criteria are typically esfablis6ed under We local grading ordinance or equivalent The nmoff volume from a two-yeaz, 1A-6our storm is a common design criteria for sedimemation aap. The sizing aiteria below assume tLat WiS nmoff volume is 0.042 ao-fUac (OS.incties of:unof~.. While t6e climatic, topogaphic, and soil type extremes make it difficult w establish a statewide standard, the following criteria should irap moderate to bigh amounts of sediment in most areas of Califomia. • Trap setUmg volume az least 67 cu. yd. per acre. • Trap sediment storage volume at least 33 cu. yd per acre (notc: the larger this volume, the less frequently tbe trap must be cleaned out). _ • Trap length greater than twice the basin widtL. • F7ood wl~e lazge enough w contain a major flood witbout upstream damage and overtopping thc embankment ins ailation ~ . . ~ Sediment traps can be constructed byexcavating a depression in tbe ground orcreating an impoandment with a barriaorlow- headdam. Sedimenttrapss6ouldbeinstallatouttidetheazeabeinggrddedands6ouldbebuiltpriortothestaztofthegrading aaivifies or removal of vegetatioa To minimiu the area disturbed by them, sediment haps should be installed 'm natural depressions or in small swales or drainageways. 'fLe following steps must be followed dncing mstailation. 1- 'ILe area ander We embenkmenE mtist be cleaied, grubbed, and stripped of any vegetation and root maL The pool arca should be cleared 2. 7be fill material for the emhanl~~t must be free of roots or otLer woody vegetarion as well as ove~sized stones, m organic material, or other objectionable material. 'ILe embankment may be compacted by travasing with equign while it is being constructed. ESC55 ' Construction HandUook 5- 88 March, 1993 `~ , , BMP: SEDIMENTTRAP objectives { _ ~- NousekeepingPrac6ces , , ~ _ ~ _ Contsin Waste _ J - -' -' ~ ;~ - - ~ ~ MinimizeDisturi~edAress .~ __ ~ ~ - ' --- = ~ ' ~ ~ / ' ' / Sfebalrzs Distur6ed Areas ' > ,~., i ~' - • _ ~ ~ Protect Slopes/Channels ~ i i ~ - - ~ ~ ~ ,~ ^ / ~ _~ ~ Contro/ Site Perimeter j ~ "~ Control Intemal Erosion ' , ' GENERAL DEFINTI ION Targeted Pollutants A sediment trap is a small, exqvated or bemied azea where runoff from small drainage a~eas ~ Sediment is detained and sediment can settle. ~ 0 Nutrients SUITABLE APPLICATIONS G Toxic Meteriels ~ • Any disNrbed area less than 5 acrai. (Sedimen[ Basins, ESC56, must be used for dcainage areas greater than 5 acres). Q OJI & Grease ~ Fbatable Maferiafs Along the peiimeter of the site at locadons w6ere sedimen[-laden runoff is discLazged off-site. ~ Other Constructan ; • Arouod and/or upslope from storm dcain inlet protection measures. Waste A[ auy point wi~hin the site where sedimen[-laded runoff can enter stabilized or ~ Uk t H natwal-ateas or waterways- ety n avs srynltkxnt /mpscr ' O ~~~ ~ INSTALLATION/APPLICATTON CRITERIA Unknownlm v~~ ~ B i u ld outside the acea to be gaded ]~gjqyg clearing, grubbing, and grading begin. • Locate where the trap can be easily cleazed of sediment • ~mplementatlon ' • Trap sizc depends on the rype of soil, siu of the drainage area, and desired sediment Requirements removal efficiency. ~ Capitel Coats ~ TLe larger the trap, the less frequenUy xd~ent must be removed. 0 O&M Coata 1Le oudet of the trap miut be stabilized with rock, vegetafloo, or another suitable Q Maintenaxe material. • A stable emetgency spillway must be installed to safely convey major floods (see • ~ Troining ' your local flood cootrol ageocy). ~ Suitabllity for . Sbpea ~59G REQU~d4 NT5 ' ~ • Mamtenance - Remove sedimen[ when the sedimrnt storage zone is no more than 1 R from ~ being fiill.. - lnspect wceklp and atter eac1~ iain. ~ Nlgh ~ Low • Cost (sounoe: EPA 1992) , - Avecage annual cost per iastal]afion and maintenance (18 month useful life) is 3 E S C 55 ~ $0.70 Pa 8- (S 1,300 per dreinage acre). LIIVIITATIONS •- OutY use for drainage areas up to 5 acres (see Sedimentation Basin BMP ST8 for ~ larga areas). ~ Qnly removes coa[se sediment (medium silt size and largcr) unless sized like a Best r sedimen~;on bas;n, Managemen ' Practices ` Construction Handbook 5- 87 March, 1993 1 f ~,w , ' ' , , ' , ' ' ' ' ' ' ' ' , ~ ~ ' ' Additionat Information - storm ~rain ~n~et Protec6on ~ ~ ~-WIRE. MESH WITH 1/2° OPENINGS % 'l ~~ ~v (~J~-~~~~~/'lw U~i~ ~~ MJ LCONCRETE BLOCK GRAVEL FILTER f3/4" TO 3" GRAVEU . OVERF~OW~ % RUNOFF WATER WITH SEDIME ~ MESH ~-DROP INLET WITH GRATE t~ ~, ~; ... -.,~,,~ ~r ~ .• ~ SEDIMENT ' : 18" MIN '' ~' ILTERED WATER BLOCK AND ~RAV t Fti T~R nr DROP IN T RUNOFF WATER 3%4" TO 3" GRAVEL WI7H SEDIMENT (12° MIN DEPTW 18" MIN WIRE.MESH IlY2" OPENINGS) WITH cb FILTER FABRIC -"- ^ OM TOP /.Y1~ . • ~I ~' SEDIMENT ~: . ' ILTEREO WATER ESC54 _GRAVEL AND WIRE MEsN Fu rFR ~ _ F.OR DROP INLET 8,,,, Construction Handliook 5. g6 Marc6, 1993 ~~~ '. 1 i _. , ' ~ ~ ~ , ' ' ' t , , ' ~ ' ' 1 Additionai lnformafion - Storm Drafn Inlet Protection , ~ ~\ ~ \ ~\\\~ ~ \~~~ j~ \\ / ~ \ \ //,j,~ ~ ' ~;;,, ; j/ ~ ~'' i ~/ ; ,/~j/ ~4 ~\ ~~ / P~ ~ yS~~P \\ ~ / , / ! / // / // ~ / ~ STORAGE VOLUME- / \ 3600 CU.FT. PER / , \ OISTURBED DRAINAGE. ~ RUNOFF BELQW TOP OF INLET: - MAX 2' ~- ~' ~ -' ~ `-. ~ MAX SLOPE 2n1 STORM WATER WITF LARGER PARTICLES REMOVED DROP INLET WEEP HOLES FOR DEWA~ ~. -- ~.r.: . . . ~ SPEC~FlC APPLICATION ~ THIS METHOD Of INLET PROTECTION t5 APPUCABLE WHERE HEA4Y FLOWS ARE EXPECTED AND WHERE AN OVERFLOW CAPABIUTY AND EASE OF MAINTENANCE ARE DESIRABLE. PARTICIES OUT ~ ~ ,. I Escs4 I Construction E7andbook 5- 85 March, 1993 ``Z ' , " Additionai infiormation - storm ~ra~n iniec Protection ~_ 1 -_ ~ ~ - . ~' ~o o °~oo~ o~o ~~ ~~ ,. Fcow i~ o oo~oo~ o~oo° ~a ~/,~ ~°Oo~ ~i// 1 /~ ~ _ ~% // 1 1 ~ GRAVEL FILTEF~- (3/4" TO 3" GRAVEL) ~ ~ 1 ~ ; SEDIMENT--~ CONCRETE Gl ' WIRE MESH WITH 1/2" OPENINGS ~FILTERED WATER ~ f ,~ .c~_ . 12" ' ~ ~ ~ ~~ ~ . CURB MLET ' GRAVEL AND WIRE MESH FILTER FOR CURB INLET ~ ' - ' . ESC54 1Y ~ l .~ Construction Handbook 5-.84 MarcL, 1993 t~,/ ' ! ii~ ' ' ~- ~ ' ' ~ 1 ' ' ' ' '. ' ' ' , ' ~ r Addifional Information - storm ~~a~n iniet Prote~tion FILTER FABRIC SEDIMENT LADEN 0 F , ~--STAKES -DROP INLET WITH GRATE ;' `-FILTER FABRIC ELEVATION WASHED GRAVEL DROP INLET - - -~~ m / ~~N I ' u ~ / e- BURIEU FILTER FABRICJ ~~. FILTER FABRIG FENCE DROP INLET FILT R Construction Aandbook 5 - 83 -- . ? Il ES~ l ... j .. a,ee. I: March, 1993 ~~, ' ' _ , ~-a ' 1 ' ' t ' ' --,} ' ' ' ' ' ' ' __,) r Additional lnformation - storm Drain inlet Protection b. Place 314 to 3 inc6 gravel over tbe filter fabric/wire mesh. 7Le depth of il~e gravel should be az least 12 inc6es over the entire inlet opening (see attached figure). Installation procedureforsand bag barrier: ~ a. Use sand bag made of geotexlile fabric (not burlap), and fill with 3/4 in. rock or 1/4 in. pea graveL b. Construct on gently sloping street c. Leave room upstream of bazrier for water to pond and sediment to senle. d. Place xveral layers of sand bags--overlapping the bags and packing ihem tightly together. e. Leave gap of one bag on We top row to serve as a spillway. F7ow from a severe storm (e.g., 10.year stoim) should not overtop ihe curb. Main~mance Reo ~'rem .n e • For filter fabric fences: Inspections shou]d be made on a regular basis, especially afier large storm events. It tLe fabric becomes clogged, it should be replaced. Sedimeot should be removed w6en it reaches approzimately one-half tbe Leight of the fence. If a sump is used, sediment should be removed when it fills appro~cimately one-half ihe deQth of tt~e 6ole. • For gtavel filters: If t6e gtavel becomes clogged with sediment, i[ must be ca~efully removed from tbe inlet, and either cleaned or replaced. Since cleaning gravel az a conswction site may be ~culy use ~he sedin~ent-laden stooe instead as fill and put fresh stoce aro~md the inlet. • 1'he inlet protec»on should be iemoved 30 days after the upsFope area has been fully stabilized. My sediment around the inlet must be carefully remwed and disposed. REFERENCES Best Management Prdctices and Frosion Convol Manual for Construction Sites, Flood Coutrol District of Maricopa County, Arizona, September 1992. "D~aR - Sedimentation and Erosioa Control, An lnventory of Current Practices", U.S.E.P.A., April, 1990. Fiosion and Sediment Control Handbook, SJ. Go]dman, K. Jackson, T.A. Bursetynsky, P.E., McGraw Hill Book Company. . Manual of Standazds of Frosion and Sediment Conlrol Measures, Association of Bay Area Governments, Jwe 1981. Pmposed Guidance Specifying ]vianagement Measures for Sources of Nonpoint Pollu6on in Coastal Waters, Wak Group Worlda8 Papa. USEPA, April, 1992. Stormwater Management Water for tLe Puget Sound Basin, Washington State Depar~ent of Ecology,lhe Teclmical Manual - Febmazy 1992, PubGcation # 91-75. Stoim Wata Pollution Prevention Handbook, First Ediflon, State of Califomia, DeQaztment of Transportation Division of New Technology, Material5, and Research, pctnber 1992 • I ESC~t II Construction Handbook 5-82 March, 1993 r \\7 ' ' (_ 1 '^ , ' ' ' ' ~ 1 ' ' 1 ' ~ Additional Information - storm Drain Inlet Protection Storm drain inlet protection consists of a sediment £ilter or an impounding area aroimd or upstream of a stmm drain, drop iNe4 or curb inleL This erosion and sedimentation control BMP prevenis excessive sediment from entering storm drainage systems prior to pem~anent stabilization of the disturbed azea i All on-site storm drain inlets should be protected. OCf-site, inlets s6ould be protected in areas where conswction activity Uacks sedimen[ onro paved azeas or where inlets receive runoff ~om d'uaubed areas. ?n~Llation/Apjication ri e 'a Planning Lazge amounts of sediment may enter the storm drain system when storm drains are installeA before the upslope drainage azea is stabilized, or where conswction is adjacen[ [o an e~cisting stocm drein. In cases of eztreme sedimentloading, the storm drein itself may clog and lose a major ponion of its ppacity. To avoid Wese probl~s, it is necessary to prevent sediment from I entering Ihe system a[ tl~e inlets. Inletcontrol measures presented in tl~is 6a~xlbook s6ould no[be used For inlets draining m~e ihan one aae. Runoff from larger disturbed azeas should be first routed through a Temporary Sediment Trap (see ESC 56). DiFferent types of inlet protection are appropriate for differeent applications depending on site conditions and the type of mle[. Inlet protection methods not presen[ed in t6is handbook should be approved by tf~e local s[orm water management agency. General Design and siziug criteria: ~ Cxates and spaces around all inlets should be xaled to prevent seepage of sedimen[-laden water. • Excavate sedimen[ sumps (where needed) I to 2 feet with 2:1 side slopes azound We inlet. Instailation procedurns for filter Cabric fence: a Place 2 inch by 2 inch wooden stakes around the perimeter of ~he inlet a ma~cimum of 3 fee[ apart and drive them S inches intn tLe ground. T6e stakes mus[ be a[ least 3 fee[ long. b. Ezcavafe a trench approzimately 8 inc6es wide and 12 inches deep around tLe outside perimeter of the stakes. c. S[aple the fil[er fabric (formazerials and specifications, see Silt Fence FSC 50) to wooden stakes so thai 32 inche fabric exteods out and can be•formed into the trenc6. Use heavy-duty wue staples az least one inch in length. d. Backf'ill tLe trench with 3/4 incL or less washed gravel all tLe way around. L-Stallation procedure tor bloclc and gravel fdter: a. Plxe hardware cloth or compaiable wire mesh with one-half mch openings over the drop inlet so tl~at the wire extends a minimum of 1 foot beyond each side of the inlet swcture. If mme than one strip is necessary, overlap the strips. "Place filter fabric rner the wire mesh. b. Plxe conaete blocks lengthwise on tLeir sides in a single row around the peaimeter of the inlet, so t6at t6e open ends face outward, not upwa~d. The ends of adjacent blockc should abut 'Ibe height of the barrier can be varied, depending on desiga needs, by stacking combinations of blocks ihat aze 4 inc6es, 8 inches, and 12 inc6es wide. TLe row of blocks s6ould be at least 12 inches bnt no greater than ?A inc6es 6igh. c. Place wue mes6 over the outside vertical face (open end) of t6e concxete blocks to pievent stane from being washed througL the bloclcs. Use hardware cloth or compazable wire mesh with one half inch openings.. d Pile was6ed stune ap~t tbe wice mesh to tLe tnp of 1he blocks. Use 3/4 tn 3 inc6 gaveL lnctallat3on procednre for gavel snd wire mes6 Ciltecs: a Place w'ue mesh over tLe drop inkt so thu fhe wire extends a minim~ of 1 foot beyond each side of the inlet savcNre. Use harclware cloth a oompareble wue mes6 with one-half mch openings. If moce Wan one strip of inesh u necessazy, overlap t6e strips. Place filter fabric over irire mesh. Construction Handbook 5 - 81 1 ` ESC54. I l~ ~ I Marcli, 1993 \~` ~\`~ Construction Handbook 5- 80 Macc6, 1993 , 1 ~ ' ' BMP: STORM DRAIN INLET PROTECTION - -c .:~.y :.;;• i~ GENERAL DEFINTTION Devices of various desigas which delain sedimenbladen nmoff and allow t6e sediment it to settle prior w dischazge mto a stotm drain inlet or catch basin. ~ SUITASLE APPLICATTONS Every stocm drain inlet receiving sediment-ladem m~off should be protected, eit6er by ' covering the inlet or promoting xd'mientation apstream of We inlet INSTALLATION/APPLICATION ' Five types of inlet protec6on are presented below, however, it is recognized that otber effective metl~ods and pioprietary device, ezist and may be selecled: er - Fil~er Fabric Frncc: Appropriate for drainage basins less t6an one acre with less ~. than a 5 percent slope. Btock and Gcavel filter. Appropriate for flows greater than OS cts. - Gravel and Wire Mes6 Filter: Used on curb or drop inlets where consvuction equipment may drive over the inkt ' - Sand bag bamer: Used to cmate a small sediment trap upstream of inlets on sloped, paved streets. - Excavaied Drop Inlet Sediment Trap: An excavated area around d~e in]et to uap ; sediment (see Sediment Ttap FSC 55). Selec[ the appropriate type of inlet protecdon and design as refened ro or az described in ihis faa shee6 ~ • Use only for dtainage areas ~all~ than o~ acre unless a sediment traQ first intercepts tbetunoff. • Provide azea around the inlet for watec tn pond without flooding shuchues and ~ ProPert3'• ~ - . ~ • Maintenance _ Inspect weekly and after each rain - ItePlace clogged filter falrric or stone 5lters immediately. ; - Remove sediment when depth ezceeds Lalf the height ofthe Piltrs, a half 1he depth of t6e sediment trap. - Remove as soon as upstream soils are stabilized a~ shuts are swept • Cost (source: EPA, 1992) '., - Averege annual cost for installation and maintenance (1 year useful life) is $150 per inleL ' ~ Constroction Aandbook 5 - 79 objectives Housekeeping Prac6ces - Contain Waste 1 Minimize Dlsturbed Areas Stabilize Distur6ed Aress Proteet Slopas/Channe/s ontrol Site Perimefe ontro! lntemal Erosion Targeted Pollutants ~ Sediment ~ ~ Nutrients 0 Toxic Materiels ~ Oil 6 Grease Q Fbateb/e Materie/s ~ Other Construction Waste ~ Llkely W Havs I Slynl9csnt/mpact Q Probabls Low w ~ . Unknown /mpect t Implemantation Requirements Q Capita! Coats ~ O&M Casfa Q Alaintenance Q Training Q Suitebility for Sbpea>5% II•HJ~ OLow III ESC54 <a: B@St Managemen ` ) Practices ~~ .,' March, ]993 ~`a ' ' ~ ' ' , ' , ' ' ~ ' 1 ' , ' ' ' Additionai information - Brusn or Rocic Fiiter 3/4" - 3.• CRUSHED ROCK FLOW -~~ n 1.5' FOR NON TRAFFIC AREAS 1.0' FOR TRAFFIC AREAS 6' SECTION 3l4" - 3" CRUSHED ROCK GRQVEL BERM TRAFFIC AREAS ~ ESC53 . II , Construction Handbook 5 - 78 March, 1993 ! \~~ ' ' ~ ' ' , ' ' ' 1 , ' ' 1 , ' r Additional Information - arusn or Rock Futer , Sieps in Conswc[ion of a Brusb Flter. l. S~ack We brush at tbe tce of a slope or along the perimeter of the site just outside tLe limits of clearing and grabbing. Tlie brush may be stacked up to 15 R high and 15 ft wide. 2. Conswct a trench 1 to 3 iL deep immediately upslope hom the brus6. ~ 3. Place filter fabric over ~he brush filter and in the trench, eztending 1 in 2 fL upslope of t6e trench. 4. Backfill ihe nench wit6 aggregate or compacted soil. The trench should be deep enwgh and backfill material sufficient in hold tbe bazrier in place during a storm. REFEREIVCES Best Management Practices and Erosion Control Manua! for Construction Sites, F7ood Contro! District of Maricopa Co~mty, Arizona, September1992. Handbook of Steel Dcainage 8c Hig6way Construction, American Iron and Steel Institute, 1983. Stormwater Managemen[ Wates for the Puget Sonnd Basin, Washington State Department of Ecology, 'Ihe Tectmiral Manual - Febmary 1992, Publicaaon ~ 91-75. I Storm Water PolluUOn Plan Handbook, Fust Fdition, State of Califomia, Department of Transportation Division of New Technology, Materials and Research, October 1992. I ESC59 I Construction Handbook 5- 77 March, 1993 `~ , , ~ Additional Information - arusn or Rock Fiiter , •- i Rock F1Ler A rock filter consists of opeh graded rock installed at the tce of a slope, along tlle perimeter of a developing or dishubed area, and ac a checkdam across consauc6on roads. Their purpose is to intercept sediment laden ronoff fmm dishubed ~ ateas of tLe site, allow ~e runoff ro pond, promote sedimentation behind We filter, and slowly release ihe water as s6eeC flow_ ~ Rock filters are appropriate wLere a temporary measure is needed ro prevent-sediments from entering rigl~[of-ways of traffic azeas such as near t6e toe of slopes, incorporated into temporary stabilized construction entrances (ESC 26), or a[ other locations along the constiuction site perimeter. Rock fil[ers ~ay aLso be used as check dams aaoss oce or more lanes of construction traffic temporary roads, or imsurfaced rights of way subject w conswction traffic. ' Advantages of ihe rock Giters are tliat ihey may be less costly Wan other temporary bazrie~, and are relatively efficient at sediment removal. . tosc~itatioa/Ap ica ion• Planning: • Rock filteis s6ould be placed along a level contour tn interc~pt s6eet Ilow. ~ ~ Allow ample room for ponding, sedimentation, and access tiy sediment removal equipmen[ betwceu t6e berm and thc [ces of slopes. F7ow tLmug6 the filter s6ould occur as sheet flow into an undisaubed or stabilized area. ~ Installauon in stream beds requires large rcek, staldng of woven wire sheathing, and daily inspecfion. Design & Sizing Criteria: T6e following design criteria are commoNy used ro coastruct filters: ~ ) • In Non-T~c Areas: ~ = Mazimum ilow-t6rough tate per square foot.of filter = 60 gpm HeigLt = 18 inches minimimm Top width =7A incLes minimum ' - Side slopes = 2:1 or tlatter ' ~ - VVoven wire sheathing (poultry netting) is recommended in areas of concentrated flow. The wire should be 1 iach~diametei hezagooal mesh, galvaz~i7cd 20 gauge. - Build the filter along on a level contour. ~ - Rock: 3/4 to 3 incLes open graded for sheet flow, 3 to 5 incl~es open gaded fot concentreted ~ow. • In Conswcfion Ttat~c Areas: ~ - Height = 12" max~um Pmvide mulaplc filtecs in series, sPaced as shown. Every 300 ft on slopes less than 5 percent Every 200 ft on slopesi w 10 percent ~ Every 100 ft on slopes greater tLan 10 percent ~ $rveh Fil rr Bnu6 filters hap and filtec sediments in a mazmer similar to otLet baRie:s in t6is hatdbook (e.g., silt fence, straw bale r barner+ rocl; filter). but have the advantage of tieing consuucted from bius6 cleared from t6e si~e and usaally disposed off-site at a cost r E~~ r_~; ~ ~ Construct~on Handlwok 5. 76 . March, 1993 \2` ' ' ' ' , ~ ' ' ' ' , , ' ' ' ' ~ ' I'i ~ BMP: BRUSH OR ROCK FlLTER (Continue) • Rock berms utay be diffiwlt to temove. • Removal problems limit iheir usefulness in landscaped areas. • Not appropriate for drainage areas greater than 5 acies. • Runoff will pond upstream of the filter, possibly causing flooding if sufficient space does no[ ezist ~ I ESC53 11 i CoruttucUon Handbook 5- 75 March, 1993 \Zy i~. i _- , ~ ' , ' ' , ' ' - '_ , ' ' ' ~ , ' ' -i ~ BMP: BRUSH OR ROCK FILTER objectives i Nousekeeping Pracdces .~/ Contain Weste Minimize Disturbed Arees 0 Stsbilize Dlsturb~fAreas . ~ ~t Slopes/Chenn ntrol Sife Perimet I I - -' - I - ~ ~~~~ ~_ ~~~~ ~ orttrol/ntemel Erosio GENERAL DEFINITION Targeted Pollutanfs A rack filter berm is made of rock 3/4 to 3 roches in diameter and placed along a level contour where sheet flow may be detained and ponded, promoting sedimentation, A biush ~~J~~~ barrier is compoxd of brus6 (usually obtained during ~he site clearing) wrapped in filter Q Nutrients cloth and anchored to We toe of the slope. If properly anchored brush or rock filters may be i M ri l ~ 7 used fa sediment trapping and velocity reduction. See CLeck Dam BMP (ESC41) for nx c ste a s more infom~ation. - ~ Oil & Grease ~ Fbatable Materials SITI'I'ABLE APPLICAI`IONS O Other Conet~vction As c6eck dams across mildl slo y ped conswcaon roads. Weste Below the toe of slopes. r ~ Uk H Along ihe Site perimeler. ~ . ey o svs SlynlAcsnt/mpaet }~ Along streams and c6annels. Q Pro6abis Cow or A['otmd tCmpp[ary spOil arCaS. Unlmown Impact • Betow otl~er small deared areaz . • At sediment traps az culvert/pipe oudets. Implementation Requirements Q Capital Coata IIVSTALLATION/APPLICATIONCRITERIA Q OdMC t • Use principally in areas where sl~eet or till flow occurs. oa s • For mcr Filter, use Iarger rock and place in a staked, wwen wire sheathing if plxed ~~~Menance wlrete concentrated ~ows occur. Q Treining • Install along a level contour. Q Suftebility for • Leave area behind berm whae nmoff can po~ and sedmment can seale. Sbpea ~5'K • Drainage azea s6onid not exceed S ac~es. REQUIRIIVIENTS • Mamtenance I ~ High ~ Lo~ - nspeCt mondily and after each rainfall. - If betm dama8ed. reshape and ~eplaa losddislodged iock. ^ - Remove sedimeots when depth reaches 1/3 of be~m height, or 1 fr. ~ ~~~ J Cost Btush fdter: Low to moderate cost if debris from on-site cleazing and gubbrog is used. - Rock filter. Expensive, since off-site materials, hand coustruction and demolifiou! removal are usually requi~ed. . Best Managemen Practices Construction Handbook 5-74 March, 1993 i ~23 Additional Information - sar,d ea9 earr~er ^ , 4" PVC PIPE FLOW ~ ,. ~ ' , ~ ~ ' ~ ~ Li ~ ~ r ~ r r r ~- ~ Corutruction Handbool~ IS" MIN I I WOVEN FABRIC SANDBAG FILLED WITH COARSE SAND-MIN WEIGHT 40 LBS. /~ 4" PVC. PIPE FOR DRAINAGE / DEPENDING ON FIELD CONDITIOtJS MIN 12" 5 - 73 March, 1993 `~, 6" MIN DIAMETER ROCK ' . ~. Additional Information = sand eag aarr~er ~ ~~~ S ~i abl . no icarions . ~ ~ ., . '` Sand bag berms may be used during constniction activities in stream beds and utiliry construction in channel§, temporary cLancel crossing for conswc[ion equipment, etc. Sand bag berms may also be installed parallel to roadway conswc- ~ tion. Sand bag berms may also be used ro aeate temporary sediment traps, retention basins and in place of siraw bales or silt fences. Ezamples of applications include: Check dams across stream channels. ' ~ Bazriers for utility trenches or otLer construction in a stream channel. A[ temporary channel crossings. May be used on a slope where straw bales and silt tences are not appropriate. , As a dive~ion dike. Fmbankmen[ for a temporary sediment basin or retention bazin. • Sediment barriecs near ihe tce of slopes. i At conswction perimeter. Advantav„~ 1 Provides a semi-permeable bazxier in potentially wet areas. 3vIme permanent t6an sIIt fences or sttaw bales. • Allows for easy relocation on site tn meet c6anging needs during const:uclion. ' inst~llation/A~litarion . Sand bag barriers may be used for secliment trapping in locations where silt feoces and straw bale barriers are not svong ~ enough. In addition, sand bag barriers are appropriate to use when conswction of check dams or sumps in a stream is j undesirable. T6e sand bag berms can provide the same function as a c6eck dam without disnabing the sveam or _/ vegetafion. 'ILe sand bag berm will also allow a small sediment reteotion azea to be created prior tn wnswcrion of final ~ detention basi~. For installaaon of a saud bag betm; the followmg criteria should be observed: Drainage Area - Up to five (5) ac~es. • Height of Berm - 18 incLes minimum heigh4 measured 5om the top of the ezisting ground at tLe upslope tce to the ~ loQ of We barrier. Wldth of Berm - 48 inches minimum width measured at We bottom of the bamer, 18 inches at the top. • Sand bag Size - Lengih 24 ro 30 inches, width 16 to 18 inc6es and t6ickness six (~ W eight (S) mcLes. Weigh[ 90 to ' 125 pounds. ' Sand bag Material - Poly~aopylene, polyethylene oi polyamide woveu fabric, minim~ unit weight four (4) ounces ~ per square yazd, mullen burst strengt6 ezceeding 300 psi and ultraviolet stability exceeding 70 percenG Use of ' biulap is discoeaged Sinee it mts and deteriotates easily. • Gtade of Sand - Coazse sand, gravel. , Runoff watu stauld bc allowed W flow over the tops of We sand bags or thmngh fonr (4) inch polyvinyl c6loride ; pipes embedded below the top layetof bags. •. Area be6ind the saod bag bama should be established according to sizing criteria for sedimeot trep BMP (FSCS~. ' REFERENCES Best Management Prectices and Erosion Control Manual for Consuuction Sites, Flood Control District of Mazicapa County..Arizona, September 1992. ' Water Quality Mauagement Plan for tLe Lake Tahoe Region, Volume II, Handbook of Management ' ESC52 Ptactices, Tahce Regional Plannuig Agency - Nrnember 1988. ~' ~. ~ Constructlon Handbook 5- 72 March, 1993 `~/ ' 1 ' t ' ' ~ ' r ~ BMP: SAND BAG BARRIER ~ .: ~ . :~ ~ ~'/.. ..~;~: _ _ ,.~, _ .. GENERAL DEFINITION Stacking sand bags along a level eonrour creates a bazria which detains sed~ent-laden water, ponding water upstream of the banier and promodng sedimentation. SUTTABLE APPLICATIONS Along ihe perimeter Of tt~esite. Check dams aaoss sveams and channels. Along stmams and chaanels. Bamer for utitity trenches in a c6annei. Across swales with small catc6ments. Division dike or betm. • Below the tne of a cleared slope. Create a [empotary sediment trap. .Around femporary spoil areas. - Below ot6er small cleared areas. INSTALLATTON/APPLICATION CRTTER7A May be used iu drainage areas up w 5 aaes. Install aloag alevel contour. ~ Base of saod bag barri~ should be a[ least 48 incLes wide. • Height of sand bag banier should be at least I8 incbes Idgl~ • 4 inch PVC pipe may be instai]ed beta,een tLe top layer of sand bags w dtain large flood flows. • Provide area beLitd bazriet for nmoff ro pond and sediment to senle, size accord'mg w sed'mient trap BMP criteria (ESC55). • Place y~g the toe of a slope. • Use sand bags large enough ~d sturdy enough to withstand major flooding Objectives Housekeeping Practitas Coniain Wasre Minimlza DisturbedAreas S66ilize Dlsturbed Areas rotectSlopes~Channe ontrol Sife Perimet ontro! Intema/ Erosio Targeted Pollutants ~ Sediment ~ Nutrienta O roxk s~ra~e~ O Oi16 Greese 0 Ffoatab/e Materis/s ~ Other Conatrucfan Waste ~ Uks/y tn Heve Slyn7flcant/mpect Q Probabb Low or ~ Unknownlmpaet - Implementation Requirements ~ Cepitel Coata Q OdM Costa ~ Meintenaixe ~ Trafning Q Suiteblrty /or Slopea>5X ~ REQU~~4IEPITS Maintenapce ~ High ~ low - ~n~a« ~ a~$ea ~a ~s ~~~y. E S ~r rJ2 f - Remove scdiment when it:eaches sic inches in depth. , C~ ~ - Sand bag bazrie~ are mrne cosdY, but rypically Lave a longer useful life than ot6er barsiers. LIMITATTONS Best ~ • Sand bags aee more eacpe~ive than other barsi~s; but also more durable. Mana emen ; ) Practices ~ • Burlap s6ould not be used fa sand bags. ~ ~ Construction Handbook 5- 71 March, 1993 \'j~ ' ' - ~ -. ~ ~ ~ r r r ' _. h~ 1 ' ' r r r - ' - ' --~ i ' Additional Information - straw Baie earrier ca ,~~~i;i'LUi;~~;~~ ~l ~,g/~. ~ ~ ~ ~> '~ ANGLE FIRST STAKE TOWAR ~ I l l/ !. I~~ ~ PREVIOUSLY LAID BALE ~~~ i j ~I J~~i ! I r~ ~t/ \ \1~,~ u y~L~~~l~ i~)I 'I~l) ,if,t~r i'~i~ '~%;~1 ~ ~~~~ ~' ~ =~~~- t ~ ~~~~ ,~ , ~~;;, ~>>, ~~~1) ' _- ~~~I~~~i n~~~ ~ll _ ~-~~~~~~~ \ , , . ~: . ` ~ eACrc~u. F~ow I,` , 11 J ~l~ . ` ~ ~ _~ V IIIII/III~ ~~~ ,` BOUND BALES PLACED - ~I I ~ , •;. ON CONTOUR. - 1~'~'. '• 2 2"x2" STAKES 1 1/2' TO 2' IN GROVND, DRIVE STAKES FLUSH i~ WITH BALES. . ~~ ~ TRENCH - 4" DEEP X WIDTH OF BALE . SUBSTITUTION OF STEEL BARS FOR WOODEN STAKES IS NOT RECOMMENDE~ DUE - TO POTENTIAI FOR DAMAGING CONSTRUCTION EQUIPMENT STRAW BALE BARRIERS ESC51 ~ ~ Construction Handbook . 5• 70 March, 1993 ~v~ U T •4~1\IIVML 1 MVl + PROMOTES ON SITE SEDIMENTATION BY CREATING A TEMPORARY POND. BEDDING DETAIL ' ~ Additional Information - straw saie Barrier A saaw baie bazrier consisu of a series of secured anchored bales placed to inteicep[ sediment-laden cunoff from small , drainage azeas of d'umrbed soil. 'Ibe bazrier ponds iunoff and allow sediment to settle. Straw bale dikes should not be used for eziended periods of time because they tend w rot and fall apazt ~ Ihe suaw baie barrier is used wheic there are no concentrations of water in a c6annel or drainageway, and wheie erosion would occur from sheet flow. TLese banieis are typically consweted below disturbed azeas subjec[ to shee[ flow of runoff. ~ Tns allatio ~Aj}y i ation _ . . ~ ~ . ~ Straw bale barziers should be used for diainage azeas no more [han 1/4 acre per ]00 feet of barrier length, with no mo~c than I00 ft upstream of any point along the bamer. TLe barrier should be placed along a level contour no geater Ihan ~ 2:1. When installed and maintained according to the guideliaes on this fact sheet, straw bele dikes remove approximately 67~Yo of ihe sediment transpotted in construction site iunoff. This optimum efficiency can only be achieved ~7uough careful maintenance, with special anention to repl~ing rotted or broken bales. TLe bemer should be conswcted on a ~ level contour to prevent concentration of (low against a small portion of the barrier. M effective shaw bale ba~rier stwuldbe installed in the following manner: ~~ , 1. Bales s6ould be place~i on the contour and in a mw with ends tighQy abutiing the adjacent bales. 2. Leave area for runoff b pond upstteam of the bazrier by locaang barrier away from the tce oF slopes. T6is also provides access fa maintenance. ~ 3. Each bale should be embedded in the soil a minimum of (4) inches and plxxd so tl~e bindings are horizonral. Bind- ings ptaced on.soil will soon disintegate and cause the barrier [o fail. 4. Bales should be securely ancLoied in piace by eill~er two stakes or re-bars driven through the bale. TLe fust stake in ~ each bale should be driven mward the previously laid bale a[ an angle to forcc the bales together. Stakes should be driven flush wi~h tLe bale. 5. Backfill and compact the expvated soil along t6e upsUeam face of the barrier. 6. . Remove the bamer when it has served its usefiilness so as nIX. to block or impede storm flow or drainage. , REFERENCES ' • Best Management Practices and Erosion Control Manual for Constrnction Sites, Flood Control District of Maricopa ' Co~mty, Arizona, September 1992. ' "Draft - Sedimeutation and Erosion Control, An Invrntory of Cntrent Practices", U.SB.P.A., April, 1990. ~ "Envuonmental Criteria Manuai^, City of Aostin, Texas. Manual of Standards oE Emsiou and Sediment Control Meas~es, Association of Bay Atea Govemments, Jun 1981. , Proposed G~dance Specifying Management Meacures for Soiaces of Nonpoint Pollufion in Coastal Watecs, Work Group Working Paper, USEPA, April. 1992. ~ Stotmwater Management Water for t6e Pnget Sound Basin, Washington State Depazunent of Eoology, The Teclmical Manual - Febroary 1992, Pnblication # 91-75. ~ Water Quality for Construction Bosinesses, City of Bellevue, Waz6ington. ~i Water Quality Managtment PJan for ihe Lake Tahoe Region, Volume II, Handbook of Management Pracflces, Tahce ~ Regional Planning Agency - November 1988. ESC51 r - ~ ,' ~~~ ' Construction Aandbook 5- 69 March, 1993 . `~ ' ~ ' ,` ' ' , r ~- r ~- r r r r r ~- r r ~~ Gonstruction IHandbook 5_ 6g Mazc6, 1993 , ~ BMP: STRAW BALE BARRIERS objactives {" _ Housekeeping Prec6tes , ~ Contain Waste Minimize Disturbed Areas 1 ~ Stsbilize Disturted Arees . ._.._.... _ .. Protect S/opes/Channels ' _ 1 I I~ I" Contro! Site Perimeter 1 ontro! Intemal Eros~o ' GENERAL DEFINITION Targeted Poltutants A sttaw bale bazrier consists of straw ~les placed end to end along a level contour in a ~ s6allow nench and staked to hold them in place. 7Le bacrier detains ruooff, creating a pond ~ Sediment behind ihe barrier wLere sedimentation occucs. ~ Nutrients SUITABLE APPLICATIONS O Toxic Materie/s ' Aloog We peiimeter of the site. 0 Oil 6 Grease Along streams and chaunels. Q Fbstable Materfels Across swales with small catchments. Q Other Constructfon ~ Around (emporary spoil areas. Wasfe Below other ~a]j, cleared areas. ~ INSTALLATION/APPLICATION CRTTERIA ~ Ukery ro Hsvs Use nmaril m azeas where sheet or Il ow occurs. Sfynlftcsnt Impaet P Y~ ~_ Q Probabb Low w~ No mote than ll4 acre per ]00 feet of barrier should drain to the bazrier. unkrwwn 7mpect ~ Install along a 1:v l onto tiT. , - ~ Place m a 4-inch deep trench. Implementatlon Backfill and comp~t the ezcavated soil on t6e upstream face of tLe bacrier. Requirements ' • Sec.~uce eac6 bale witL two stakes. ~ Capitaf Costs • I.cave enough area (about 1200 sq. R per aae) behind tbe barrier fa nmoff to pond ' (no morc than I S ft depib) and sediment to settle. ~ O&M Cosfa ~ Msintenance REQUIREMEN~I~S ~ Q Treining ' • Maintenance Q Suit~bflity /or 'i Inspect weekly and after each rein. Sbpea>5% - Replace bales which have decomposed or whose bind"mgs have brokea ~ - Remove sed~wt be6ind the bazriea when it reacLes a depth of 6 mcLes. • Costs (source: EPA, 1992) - Avecage avnuai cost for installation and maintenance (ass~es 3 monih useful ~ life): 317 per lineai foot (56,800 per drainage acre). t n~.rn~ ~ mr~vn -~ HI9II ~ LOW • Straw bate barrie:s aze not to be ~ued for eztended periods of time because they tend tn E S C51 rot and fall aparL '_ • Suitable only for s6eet flow on slopes of 296 or flaper. • Not appropriatc for large draiuage areas, limit to one aae or less. ~ •. Straw bales lose tLeir effectiveness rapidly due to rotting, thus constaot maintenauce is requued. • Not recommended for mncentrated flow, inlet protectiou, ctannel flow, and live B@St - S~' Managemen t , Bale bind'mgs of jutc or coUOn not iemmmended. i p~CtiCBS - ' Construction Handlwok 5- 67 1March, 1993 ~~ ' i , ~, ~~~ , ' ' ' ' ~ ' `; ' v r ~ ~ ~. ~ f ~=v~ r Additional Information - siit Fence 2" X 4" WOOD POST. STANDARD OR BETTER OR E~UAL ALTERNATE: STEEL FENCE POST ,~-FILTER FABRIC MATERIA~ 60" WIQE RO~IS. % USE STAPLES OR WIRE RINGS TO ATTATCH r~ FABRIC TO WIRE / -2"X2"14GAWIRE i FABRIC OR EOUIV.' v~ N O (D ~ ~ - ..' ' " ~/\~7.\V>` _„ ' ._ .'\~7\`1T~/\~/\~7F' ' . ~ ~ ~ I . p ++ _ _ _ _ - _I I ~ ~ ~ ~BURY BOTTOM OF FILTER MATERIAL ~ I I I IN 8" X 12" TRENCH I ~ I 6' MAX. L FILTER FABRIC MATERIAt-~ ~ ~ 2° X 2" 14 GA WIRE FABRIC OR EOUIV. ~ FOLD 8 SET FILTER FABRIC INTO SOIL ~ I_ 12" BACKFlLL AND COMPACT THE EXCAVATED-- SOII. IN TRENCH AND ON BO7H SIDES -OF FILTER FENCE FABRIC 2" X 4" WOOD POST A~T: STEEL FENCE i m FIOW ~ ESC50 ~ Construction Handbouk. 5. 66 March, 1993 ~ ~3~ ~1 1 ~ , ~ ~ r r r r ~- ~- r r- r r r~ . r Additional information - s~it Fence Best Management Practices and Erosion Conrrol Manual for Construction Sites, Flood Control Distric[ of Maricopa Co~mty, Arizcrna, September1992. Enviro~mental Action Manual, City of Ausdn, Tezaz, 1989. . Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Govemments, Jun 198i. Proposed Guidance Specifying Managemem Measures for Sources of Nonpoint Pollufion in Coastal Waters, Work Group Working Paper, USEPA; Aprii, 1992. Sedimentatlon and Erosion Control Prdcfices, An Introductory of Current Prac6ces (Drafl), USEPA, 1990. Stormwa[er Management Manual for T'6e Puget Sound Basin, Washington State Depaztment of Ecology; Public Review ~4 1991. - Water Quality Management Plan for the Lake Tahce Region, VoTume II, Handbook of Management Practices, Tahce Regional Planning Agency - November 1988. I ESC50 11 Construction Handbook 5- 65 ~Iarch, 1993 \~J~i ~ , ~~ Additional Information - siit Fe~ce ~-, '~~ To reduce [he cbance of clo in it is referable to s ci a fabric with o n s as lar e as allowed b ihe aiteria. No S8~ 8. P Pe fY P~ S B Y fabric should be specified wi~h an EOS smaller than U.S. Standard Sieve No. ]00 [0.0059 in. (0.15 mmJj. If 85 percent or more of a soil, by weigh4 passes duough Ihe openings in a No. 200 sieve [0.0029 in. (0.074 mm.)j; filter fabric s6ould ~- not be used. Most of the particles in such a soil would not be retained if the EOS was too large, and ~hey would dog t6e fabric quickly if the EOS was small enough ro caphue the soil. 'ILe fence should be supported by a wue mesh if the fabric selected does not have sufficient streagth and bursting ' strength characteristics for the plaru~ed application ( as recommended by t6e fabric manufacuuer). Filter fabric material s6ould contain ultraviolet ray in6ibito~ and stabilizers to provide a minimum of six months of espected usable consVUC- tion life at a temperawre range of 0' F. to 120' F. Installadon Guidelines: Fil[er fences aze to be constructed on a level contour. Suff3cien[ area should exist behind We fence for ponding to occur without 77ooding or overtopping the feuce. ~ Posts should be spaced a maximum of 6 feet apart and driven securely intn ~he gro~md a minimum of 30 inches. • A trench should be ezcavated appmximately 8 incLes wide and 12 inches deep along tbe line of posts and upslope ~ . from We bamer. W6eu srandard svength filter fabric is used, a wire mes6 support fence should be fastened securely to tl~e upslope side of the posts using heavy-duty wire staples ai leasi 1 inch long, tie wires or 6og rings. TLe wire sLould eztend ~" inro the treach a minimum of 4 incbes. • 7Le standard saengt6 51ter fabric should be stapled or wired to the fwce, and 40 inches of the fabric should eztend into We trench. When ezua-strength Cilter fabric and closer post spacing are used, the wue mesh support fence may ~-- be eliminated aud tbe filter fabric stapled or wiced d'uectly to tlie pasu. Avoid the ux of joints. TLe filter fabric should be purchascd in a continuous roll, then cut to the length of t6e j batrier. When jomts are necessary, filter cloth should be spliced.together only at a suppon pos4 ~~ a minimum 6 -- inch ovedap, and both ends securely fastened to Ihe post . ~ TLe trench should be backCilled with compacted native material. . ~ ~ Maintenance: Inspect monthly durmg dry periods and immediately aflea each rainfall. Repair as necessa(y. Sediment must be removed when it reaches approzimately one third the heigh[ of the fence, especially if heavy rains are expected. '. . Filta feoces should not be removed until the upslppe azeaLu been pe[manendy stabilized. ' ~Fil~ ces will aeate a temporary sed~entation pond on t6e upstream side of the fence and may eause temporary ' flooding. Fences not eoacwcted on a kvel contour wiD be ovenopped by conceatrared flow resulting in failure of _ iGe filter fencx._ • cs • Filter fencxs are ~ paacticai wheie large flows of watra are involved, hence t6e need ro restrid their nse to drainage areas of one xae a kss, and flow iates of ]ess than 0.5 cfs. _ • Problems may atise from incaarect selection of pae size and/or improper installaaon. . , • Do not aIlow water deptL w ezcced 1.5 R az any point . ' ~ProP~ly installed fences aze subject to failure from undetcutting. overlaPP~B, ar collapsing. ' ESC50 ' Cortstruction Aandbook S- 64 . March, 1993 ~3~ ' ' i , , ' ' ' ' ' ' L~ Additional Information - Silf Fence A silt fence is a temporary sediment barrier consisting of filter fabric stietched acrossand aVached to supponing posts, envenched, and, depending upon iLe sUength of the fabriC used, s~pported with wue fence. Silt fences trap sediment in [wo ways: (1) by in~rcepting and detaining cma~l mnnnrc of sediment from disturbed areas during construction opera- tions in order to promote sedimenta[iou behind the fence; and (2) by decreasing the velocity of low t]ows (up to 0.5 cfs) in swales_ Silt fences maq be used for perimeier controi, placed upsveam of the point(s) of discLazge of shee[ flow from a site. 'Ibey may aLso be used as interior controls below dishsbed azeaz where runoff may occur in the.fmm of sheet and rill erosion, and perpendicular to minor swales or ditch lines for up to one acxe convibuting dcainage areas. Silt fences are generally ineCtective in locations w6ere the flow is concent:ated and are only applicable for s6ee[ or overland flows. Pl~ning: Sil[ fences are genecally most effective when tt~e following placement criteria aze followed: • Limit the upstceam drainage area to I aae or less when used alone or in combination with sediment basin in a larger site. •'Ihe macimum slope perpendicular to the fence line should be I:1. •.. Limit che mazimum sheet or overland flow path lengiL to any point along tbe fence to 100 feeL • Limit tbe concenuated flows reaching the fence to 0.5 cfs, Silt fences are preferable to straw bame~ in many cxses. Laboratory work at the V'uginia Highway ~d Transportafion Reseazch Council has s6own tLat silt fences can trap a much higher percentage of suspended sediments tLan can straw bales. While the failure rate of silt fences is lower than tha[ of straw baaiers; there azc maz~y instances where sil[ fences Lave been improperiy installed. The following mstallation metbods can impmve perfom~ance and should be followed: • Constiuc[ tLe silt feace along a Ievel conrour. , • Sil[ fences should remain in placc until the disturbed area is permanently stabilized. • Provide sufficient ioom for runoff to pcmd belund the fence and to allow sediment removal equipment tn pass betwcen the silt fence and toes of slopes or otLer obsiructions. About 1200 sq. ft of ponding ama should be provided for every aae draining tn the fence. • Tum the ends of the filter fence uphill to pcevent stom~ water from flowing around the fence. • I.eave an undisturbed or stabilized area immediately downslope from the fence. • Do not piace in live streams a intumittendy flowmg cham~els. Design: Selection of a filter fabric is based on soil conditions at the ~vnshuction site (which affect t6e equivalent opening size. (EOS) fabric specifca6on) and characteristics of the support fence (which affect the choice of tensile strengt6). T6e designer should specify a filter fabric fhat retains tLe soil found on the conswcdon site yet will have openings ]arge enoug6 to permit ~ainage and prevent clogging. TLc following aiteria is recommeoded for selection of the equivalent oPeninB size: i. If 50 pereent or less of the soil, by weig6t, will ~ss t6e U.S. sfandard sieve No. 20D, select the EAS to:etain 85 percent of tLe soil. The EOS should na be Fmer tLan EOS 70. 2. Fot all othet soil types, the EOS should be no larget than the openiugs iu tbe U.S. Standard Sieve No. 70 [0.0083 ia (0.21 mm.)] except wLere direct discharge to a stream, lake, or wedand will oocur, tL~ tLe EOS s6ould be no larger iLan Staodard Sieve No.100. ~_ Co~utruction Handbook 5 - 63 ESC50 ~ ' ) ~,~.. ~ ; Marc6, 1993 ~,~ • BMP: SILTFENCE ~ objectives Housekeeping Praedees - -' - - _ - Contain Waste -. - - ' - Minimize Disturbed Areas _ - _ - - _ - - StabiliteDlsturbedArees - ~ _ " _ i ~ Protect Slopes/Channels - ~ ~ ' ~ onfrol Site Perimeter ~ ontrol lntemaf Erosio ~ ~ i GENERAL DFSCRIPTION ; Targeted Pollutants A silt fence is made of a filter fabric wlilc6 has been entrenched, attached to supporting ~~f~~~ poles, ar~d sometimes backed by a wire fence for support. The silt feoce detaias sed~ent- 0 Nutrients laden water, promoring sedimeatation behind the fence. ~ Toxic Meteriela SUTTABLE APPLICATIONS ~ Oil b Grease ' Along ~he pecimeter of the site. Q Fbatab/e Materiala Selow the ~ of a cleared slope. Q Other ConatruMlon ,vong streams az,a cnannels. wasre Around tcmporary spoil aceac. Across swales witb catchments less than 1 acre. ~ Uke/y te Hevs ' Below otLet small cleazed areas. . SlynlBcant Impact I _ ~ ~ Pro6sbM Low or Unlmown Impsct IlVSTALLATION/APPLICATION Use principally in areas where s6eet flow occuis. Implementation Install along a?evel contn~r, ~ water dces not pond more tLan IS feet at any poin~ Requireme~ts No moie than 1 acre, 100 ft, a OS cfs of concentrated tlow should drain to any point along tl~e silt fence. Q CapRa1 Coata • Turn ends of fence uphill. Q OdM Costs • Provide acea behind ~he frnce fvr nnwff to pond and sediment W settle (appmx. 1200 0~iMena~e sq. ft pec xre dcaining w the silt fena). Select filter fabric which retaias 85% of the soil, by weight, besed on sieve analysis, 0 Trs/ning but is not finer than an equivalent opeuing size of 70. ~ Suitabifity lor Slopes>5% REQUIRII44fEEIVTS • Mainte~ance - Inspect weekly and afier eacL cainfaIl. - Repair wherever feuce is damaged, _ - R~ove sediment wben it rcacLes 1/3 the Leig6t. of t6e fence. ~ H h 0 L ' • Cost (somce: EPA, 1992) lg ow - Avecage aonual cost fot installatiou and mainteaance (ass~es 6 month asefiil ~ C~1 0 life): S7 per lineal foot (5850 per drainage xre) . ~ J V LIlKITATIONS • Do not use whele 85% of the soil, by weigh4 p~ses through a No. 200 sieve because tLe filcer fabric wiil clog. ' • Do not place fence on a siope, or across any contovr line. ' ~gt • Do noc use in sue~s, channels, or anywhece IIow Las concenaarea. Managemen • Do not use in locations where pcwded water may quse flooding. prdCtiCes Construction Handbook 5 - 62 Macch, 1993 1 . `~ Additional Information = sioPe Ro~gner,~ngR'errae~ng DEBRIS FROM SLOPE ABOVE IS CAUGHT BY STEPS DRqfNAGE . O AC IOl J( ~/~C /`` Z" _ 15„ ~ A~ff A r 3" .,~~- 6ROOVING IS CUTTING FURROWS ALONG THE CONTOUR OF A SLOPE. IRREGULARITIES IN THE SOIL ~ SURFACE ~ ~ CATCH RAINWATER AND PROVIDE SOME COVERAGE OF LIME, FERTILIZER AND SEED. GROOVING SLOPES STAIR-STEPPING CUT SLOPES ~ - - . AdD ~ROOV{N~ SLOPES ~~ ~ 0 .c . WATER. SOIL, AND FERTILIZER '' ARE HELD BY STEPS - PLANTS ~~ CAN BECOME ESTABLISHED ON THE STEPS. STAIR STEPPING CUT SLOPES o n ° a a a e a o~ °~e 000 oaaa a.a ° °o oa e a a. e aao a a eo a ~ a a a°o o °~°e I ESC42 11 Construction Aandbook 5-61 March, 1993 ~~ i ~ Additional Information - sioPe aouyneninyrrerracing , ,- . ~~ Slope roughen~g/terracing creates uneven depressions, steps or grooves on the soil surface to aid in establishment of vegetabon, reduce runoff velocity, increase infiltration, and provide for sedimwt trapping. ,' Surtace roughening may be applied in all slopes steeper Wan 3:1, and greater than 5 vettical feet, ptoviding some inslant erosion protection on bare soil while vegetative cover is being establis6ed. It is an inezpensive, simple and short-temi emsion convol measure for roadway cut slopes. , Terr~ing usually is a moic pemianent measure used tn stabilize a steep slope. Temaces strould be designed by a regis- tered professional engineer and included in ~he project conswcdon plans. Local design criteria should be used. ' Ins allatio /Annlin ion Graded azeas w~t6 smoot6, hard surfaces give a false impres~ion of "Hnished gtading" and a job wel! dooe. It is difficult to esablish vegetadon on suc6 surfaces due to reduced water inY'iltration and tt~e poientia! for erosion. RougL slope . '`- surfxes with uneven soil and rocks left in place may appcar unattractive or unfinis6ed a[ fi~4 but t6ey encoucage water ~lvation, speed tLe establishmeot of vegetation; and deaeased cunoff velocity. Rough, loose soil surfaces give lime, fertilizer, and seed some natmaf coverage. Niches in the surface provide microclimates which generally provide a cooler ~ ard morc favorable moishue level than hard f7at surfaces; Wis aids seed germination. Tl~ere are diffe~ent metbods for achieving a roughened soil sutface on a slope, and the selection of an appropriate metl~od depends upon tl~e [ype of slope. Roughening meWods include stair-step gradiug, gmoving, and tracldng. Factms to be . , considered in cho~sing a me[hod are slope steepness, mowiog requirements, and whetLa the slope is fo~med by cutting or filling. ~ 1, Dishubed areas which will not requue mowu~g may be stairvstep graded, grooved, or leFt roug6 af[ei Filling. `.; 2. Crtacled areas steeper than 3:1 s6ould be stair-stepped with benc6es (See 6gure at end of fact shcet). TLe sta'v- ~ steping will help vegetation become atiached and also trap soil eroded from the slopes above. Sta'u-step grnding u P~~~~1Y aPprop~~ ~n soils containing )arge amounts of soft rock. Each "step" ptches materiat which sloughs ' from above, and provides a levei sire where vegetation c~ bernme established. Stairs should be wide enough to work with standard earth moving equipment 3. Areas whic6 will be mowed (there areas should Lave slopes less than 3:1) may have ~all furrows left by disking, harrowing, relong. or seed-planting machinery operated on the contour: ' 4• It is imporrant to avoid ezcessive compacting of the soil surface when scarifying, Tcxking with bulldoza heads is prcfereble to not roughening at all, but is not as effective as other fmms of roughening, as t6e sod sucface is seveiely compacted and nmoff is iuueased, Tracking can ba ~complished in a variety of ways, iocluding "hack wall~ng," , or driving a crewler Uactnr up and down tLe slope, in leaviug a pazteln of cleaz imprinis paratlet to slope contours. REFERENCES ; Best Management Pracdces and Fiosion Control Manuai for Consm~ction Sites, Flood Control District of Mazicopa County, Arizona, SeZNember 1992. ~ Handbook of 5tee1, Diainage & I-Tghway Construcfion, Americ~ Imn and Steel Instimte, 1983. Proposed Guidance Spocifymg Managemenc Measures for Sources of Nonpoint Polluflon in Coastat Watecs, Wock ~P K'or~& p~. USEPA, Aprii, 1992. ' Stotmwater Maoagement Water for the Puget Sound Basin, VVashingion Statc Deparunent of EcologY.'Ihe Technical Maoual - Febmazy 1992, Publication # 91-75. ' ~ ESC42 II ' Co~truction Handbook 5- 60 March, 1993 `3~ , 1 _. i~ , ' BMP: SLOPE ROUGHENINGITERRACING ~~ ob~a~t~~a5 Housekeeping Practlces Contsin Waste Minimize Disturbod Neas fa6ilize Distm6ad Area rotact Slopss/Channe Contro! Site Perimeter Control tntema/ Erosion , GENERAL DEFIIVTTION Targeted Poliutants Slope roughening/temdcing creates microclimates fa establishing vegetation, Teduces ~~~~nt ' runoff velocity, increases infiltration, and provides small depressions for trapping sedi- ment 0 Nutrienfa ~ Toxic Materiafs ' SUITABLE APPLICATIONS Q Oil S Grea+e rea Any.cleared area prior to seeding and planting. t b/ ~ Ff M i / R uued for cleazed, etodible slo • eq pes steeper tLan 3:1 and higher than 5 fcet prior to oa a e ater a s seeding and plaoting. ~ Other ConsLuction , - Waste INSTALLATION/APPLICATION CRTl'ERIA Slope mughening/leiracing is performed in several ways: ~ Ukely m Havs . I Stait-SfC tn . ~ . P 8~ R 5lyn/Rtantlmpaet O Probab/ Lo Gt00ving. s w or ' ~ - F i Unknownlmpxt . u~iOw ng. Traeking. . Impleme~tation ' Rougb grading. Requirements . Nogading. • O Capifaf Coata ' REQUIRIII~NTS • M i u O 06M Costa a nte auCe - In t mu hened 51 spec g opes weekly and after reinfaII for ezcessive erosion. O-Mefnfenante - Revegetate as quickly as possible. ~ Treining ~ • Cost (source: EPA, 1992) ~ Suitabfllty for . -- Surface Rpughening: Petfmmed at no (e.g., rough gradinp~ ro low (e.g., track- Sbpea >59L ingJ cosL ~ Turacing: Average annual cost is $4 per linear foot (2 year nseful life). LD~II'PATIONS • Ro h i ~ ug en ng is of limited efCectiveness on its own, but is nsed to speed ievegetation. ~ H(gh ~ -Low ~ Esc42 r ~St ~ Managemen PracUces { r Construction Handbook $_ 59 March, 1993 w `~" ' ' , Y ~ , , ' , ' , ' `1 _~ r r' r ~ ~ r ~. ' JI L ~ , Additional Information - cneck oams 4"-6" LOGS ~ ~ ~~ - -r~-i ~'~ ~-` ~I r-r-~ a. ~-~tr Y~~- N /~~~ ,'~j~~ I ~ ~ ~ ~ i~``~\ ~/~~~i!~~~ ~ i i i i i i i~~ I'/,.~~ \~//. ~ ~ i i i ~. .~/ . in DRIVEN WOODEN PILES LOG CHECK DAM ROCK CNECK DAM CROSS-SECTION l a THE DISTANCE SUCH THAT POINTS A 8 B ARE OF EOUAL ELEVATION I ESC41 I SPACIN~ BETWEEN CHECK DAMS Construction Aandbook 5-58 Ivlarch, 1993 i ~ ~~ ROCK CHECK DAM ' , ~ ' ' ' ~ ' r ' i r ~ r ~ ~ r ~ Additional Information - cneck ~ams Check damS create small pools in swales and ditches which drain 10 8aes or less. These poois reduce the velocity of ._ sto[m water tlows, thus teducing erosion of tl~e swale{ditch. Sedimenlation also occurs in these small pools, but probably ~ results in little net sediment removal because of the smatl deicntion time and probable scour during longer~storms. A sediment uap (ESC55) may be placed immediately upstream of tbe check darn to increase ~sediment removal eCficiency (but never in a nanual stream or channel). Chuk dams should not be placed in swales/ditches with a base flow during some or all.of the year. Ins alla ion~Annlication Criteria Check dams must be sized and consuucted correctly and maintained properly, or they will be either washed out or cause ^ooding. Check dams can be constructed of eitLer rock or logs. Use of other namral matenals available on-site that can withstand We stormwatu 17ow velocities is acceptable, such as pea-gravel filled in sand bags. Check damsshould ~ be constructed from straw bales or sil[ fences, since concenvated flows quickly wash out these materials. A sediment vap (ESC55) may be installed immediately upsueau~ of the check dam, but may be oF limiied eflectiveness if channel flows aze large enough to xour the vap during moderate to large srorms. Maximum velocity reduction is achieved if tbe toe of the upsveam dam is at ihe same elevation as the wp of the downsveam dam. 7'6e center section of tl~e dam s6ould be lower tLan the edge secaons so t6at iLe check dam will act like a weir during major floods. Rock c6eck dams are usually consWCted of appropriately 8"-12" rock. The rock is ptaced either by 6and or mechani- cally, but never just dumped into the channel. The dam must completely span tbe ditch or swale ro prevent washout. The roclc used must be large enough to stay in place given ihe expected design flow throug6 the c6annel. Log chuk dams are usvally cooswcted of 4 ro 6-inc6 diameter logs. The logs should be embedded intn ihe soil at least 18 inches. If grass is planted to stabilize ihe ditch or swale, the c6eck dam should be removed when the grass has matured (unless ihe slope of the swale is greater ihan 4 percent). ~~~ ~ Best Management Practices and Erosion Control Manual for Conswction Sites, Flood Control Disuict of Mariposa Coimty, Arizona, September 1992. , "Ihaft - Sedimentation and Erosion ConUOI, M Inventory of Cutrent Practices", U.S.E.P.A., April, 1990. I Manual of Standards of Erosion and Sediment Control Measwes, Association of Bay Area Govemments, June 1981. ' Stotmwater ivfanagement Water for the Puget Sound Basia, Was6ington State Department of Ecology, T6e Technical Manual - Febmary 1992, Publication ~! 91-75. Water Quality Management Plan for the Lake Tahce Region, Volume II, Handbook oFManagement Practices, Tahce Regional Planning Agency - November 1988. ESC41 ~; ' Construction Handbook , 5• 57 March, 1993 ~~ , ' ; l;t , ' ' , ' ' ' ~ ' y ' . ' ' . '. ' 1 ' BMP: CHECKDAMS objectives Housekeeping Practices , Contain WasJe Minimize Disturbed ,4ieas - Stebilize Dlstud~ed Areas ~ Protect Slopes/Channels ~ - ( Confrol Site Perimeter Contro! intemal Erosion GENERAL DFSCRIPTION Targeted Pollutants Small temporuy dams construcled across a swale or d[ainage ditch. Check dams reduce ~~~~nt the velocity oF concentreted stoimwater flows, theieby reducing erosioo of the swale or tri t 0 N ditch, and promoting sedimentation beLind the dam. If prope;ly anchored, biush or rock u en a filtet berms (ESC53) may be used Cor check dams. ~ Toxic Materiafs - . ~ ~ Oil & Giesse . SUITABLE APPLICATIONS t b/ M i ~ Fb Used ro preveat erosion by teducing the velocity of channel flow in small intemittent e a e ater s/a chancels and temporary swales. ~ Other Conatnretion May also promote sedimentaaon behind the dam, but should not be considered to be a Waste primary sediment trapping device because subsequent srmms will scour and resus- ~ uk / r H pend much of the vapped sedimen[. e y avs o S/ynlflcantlmpect IIVSTALLATION/APPLICATION (.'RI'I'ERIA ~ Unkr~ow~n mpe~ct C6eck dams s6ould be placed az a distance and hei ht to allow small l f [ g poo s o orm between eacb one. Implementation • Backwater from a downstream check dam should reach the tce of t6e upstceam cLeck Requirements dam. Major floods (2 year storm or ]arger) should safely flow over tLe chec~c dam wiWOUt • 0 Capital Coata an increase in upsheam flooding or desftuction of the checkdam. ~ OdM Coafs • Primarily used in small, steep d~aanels where velocities exceed 2 fps. Q Maintenance •. Used iu steep tersain where velocity reducdon is required. ~ Training • A deep sump may be provided immediately upstream of the check dam to capdve , ezcessive sediment ~ Suitabiliry /or ~i • Check dams ma be built of rocks or lo Y 8~+ w~~ ~~~ against damage d~uing Stnpea ~5'K significanc noods. REQUIItII1g'1VT5 • Mamtenance - tnspec[ for sediment buildup behind ilie cLeck dam and sigus of erosion aioimd ~ High ~ Low the check dam after each rem . Rertiove acc~ulated sediment whecever it reacLes one-half the sump deptA. • Cost ~~~~ ~ See CalTcaos Cost Scd~edule for iegidoa! cost data. LI14II'CATIONS • Usc only in small opeu c6annels which drain 10 aaes of less. • Not to be used in live sueams. Best • Do no[ instau in Iined or vegerated channets. Managemen PracBces ; ' Construction Handbook 5- 56 ' March, 1993 ~~` ' ' t- ~ ~ , ' I ~ I 1 ~r I ~ ~ ' r r r r r r ~ Additional Information - outiet Procection ~ T- ~ ~ I La 9~- OOOO O O O ~ ~ FILTER FABRIC SECTION A-A PIPE OUTLET TO FLAT AREA WITH ~NO DEFINED CHANNEL . v la = LENGTH OF APRON do = INSIDE PIPE DIAMETER w = APRON WIDTH d = APRON THICKNESS NOTES 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, OR CONCRETE 2. PIPE DIAMETER, APRON DIMENSIONS, AND AVERAGE ROCK SIZE FOR RIPRAP ARE BASED ON THE DESIGN FLOW RATE AND VELOCIN. La AND ROCK SIZE MUST BE SET TO SLOW THE FLOW TO NON-EROSIVE VELOCITIES (e.g., LESS THAN 10 tps)_ SEE CALTRANS AND LOCAL AGENCY DESIGN CRITERIA FOR APPROPRIATE SIZING CRITERIA. 3. d= 1.5 TIMES THE MAXIMUM ROCK SIZE DIAMETER BUT NOT LESS THAN 6 WCHES. FILTER FABRIC! SECTION B-8 PIPE OUTLET TO WELL-DEFINED CHANNEL pIPE OU7LET CONDITIONS I ESC40 .11 ~ Construc6on Handbook 5- 55 Mareh;1993 ~~'(,~' 1 ~ ?` Jy a ~-aT. o` oe ~,_ = e ?° i 1 - ~ ~+~ Q= C ?F L! P~ ~ ~ ~O ~ 1P ~ p~ F. . r .. 0 . . J p .4p o4 tie . m~ p BMP/design yya~ 1~e ~e 1o c ,` ~ ?O ¢_' ? ~2 ~ 4~~P ~~ T' ~ " EllTENDED OETENTION PONO~ ' . - . . ~ i ' DESIGN t ~ v 3 O ~ ~ ' YOOEPATE ` . . ~ - '' UESIGN 2 ~ O O. O ~ ~ MOOEMtE - ~ESIGN 3 ~ ~ ~ O '~ ~ NIOM . KEY: . t WET PONO . ~ O 0 TO 20x pEMOVAt ~ O 20 TO ~01cREY0VAl -' OESIGN ~ e O O O Q Q YODEMTE - ~ O •0 i0 EO'YREYOVAI ~ ~ESIGN 5 Q O O ~o ~ ~. ~ODEIUTE - ' ~ ~ ~ e0 TO DOx qEYO~AI DESIGN E s e 0 O ~ Q „~~M r• BO TO t00X pEMDYAL INFILTMTION TRENLH ~ (~ INBUFFIGIENT ~ ' OESIGN 7 a O O ~ ~ .~ YDDEPATE KNOWIED~E ~ . DESIaN a ~• O O Q S _~ ~~ HI~N - OE91GN 9 ~ ~ ~ . S • ~ HIUM ~ . ' - . , INFILTlIkT10N BASIN _ , ~ OE9IGx ] ~ O O ~ O a 400EMTE ' . OE9IQN E ~ O 0 ~ ~ a ' NIGN , ' ' oesiaN e ~ ~ ~ • ~ ~ wcn POflDUS PAVENENT - UEBION 7 ~ O' A O ~ O A VOOERATE - ' OESICN B O ~ ~ . ~ . ~ - ~ eiaH - . ~ - OESIGN 9 • .a 9 ! ~ ~ MIGM~ ~ ~ . '~ . ' 1TFTER OUIILITY INLET ~ ~ oesicN ~o O . ~.: !~ ~ C~ ~ ~ow FILiER STNIP _ - . ' ' . OESIGN 11 O O O O O ~ ~W ' . ' DESIGN 73 '. Q O ~- ~ ~ ' MODERATE '^ . UMSSEO Sw~LE . ~ ~ . . oesicN ~a O O O O O ~ ~w - ~ OESIGNI~ n ~Q Q Q ~ ~ ~ow ~ , ~ - Uesign 1: Fiut-flush runoff volume denaiaed for 6-:2 6ouzs. ' " Design 2: Ruaof: volu~e produced by 1.0 inch, decained 24 6ou:s. ~ . D:sign 3: As ia Design 2, but r:ich shallar mazsh :n 6ossom~stage. ~ , ~ - ~ ' Design 4: Permmm: paol eqnal to 0.5 ix~ch scozage.pez ?mpervious acze. ~esign Sc Pezmanen: pool equal no 2.i (Y'r); rhere Vr-~ean sconm zuno?f. - Les?~ 6:, 2ezhnen: pool- equa? 20 4.0 (4r); apprez. 2 eeeks retencioa. . - besign 7: Facilise ez?il.xates firsi-'_lush;_G.S inch n:nof`/impez. ac.e_ . . , Desi~ e: Facili:y es:iltra:es one iach zuao:_' voime ,xr imoer- acre.~ ~' Design 9: iacilS=p ez:'_Icraces ai? ^aaoff, uo :o :ne 2 pear 3es;gn 5=oz. -es?gc l0a .00 cu6ic feec ves siorage per iaoercious acre.~- - - ~ ~esign il: 20 Fcoc c:te s_:° s:cip. ~ - , ~. -esign~l2:- 10C foac rfde 'ares:et s:.ip, eitt level spreacec. ' ~ -es?gn 13: :!g_ slax svales, cict r.o eaeck caes. ~ ~ Duiga ~I~: L..-~: g-:ad?ea; sexies v_ h check dems. _ - ' ~OMPARATIVE POLLUTANT REMOVAL OF ~ RBAN BMF DESIGNS , Spurce: Riverside Co. Flood Control 8 Water Conservation District '~ uf„Mf! e sR~i] ~ Q3~~Ie '~`!~ : Q r!~ ,;t d~(eaa. , •s daaies ajoui -ilf Ev" oj pu auop a~{ s~e~ {ey~;auiH7awu~. ~ttEM~7 ~~T~I ~~ ~ . : SaT~T~ ~LT[C[~2AIS ,'a~am e a~uo u; q}uopi e a~i, ~ . ~ .. =Peai roCeiq.Buidaapys wc t~yn~m ~pe4s~ae~, uc 5~ei3 . `aea~ e OIXI`5Z$~BQ-a~7'III se I `, -lsanu? u6 4~?x~: PaHSF[dcp ~ ~ - ice~ `aanamoi~ `8ucdaatiis. y i , ; :10~ . ,~i~qnd s,:ia~a ~aq;:'sazel~ ~ pies 'sK~smaprs gue ~s{d~ _ 'sYaa,rys vo ~e8'qiuaa ase~ ~ 8uiueat2 :[pea}s ioF~ .fEd o~ .. . . .. II!~ 7eq7 :rea.f e OOU'O6$ ~3 . - ;~a~to~,ol~saddq:~Aia-ay;'c ~ 's~'xaah~~ ~atm; seaze~Tec~iaiucuo~ pue, Qs~aam seaae iei;u~p~sal~ sai ~.sdaa.~s qa~qm'q~e@g opuopa~~ ~ 7ueu4~apajsqaae~'s e 7n¢q7va a~egi'iae~ sa;j~~.: It~ius atiios aey~ ~uaru~iqtwo~ Ie~~'ueu~j ia2ae~ e aambas ua~~o s~oj~a asoqj ;u~ ; P??~ mo[ &?ui, a~ ~~QLL.~ asn }o lt~o i~aj .i~a3c •uea~o aq1 ' o;~[i i{sem ~'i~sea ai ~.;~~-:`~~.1... ,t .r 'I 1 '3 n ~.r F E , ~ O t7neFlaw€'; ~ ~SSE$ ~ll_ i _ " Citx'officials f i.e t t t a : n r g. `~ a Y~++b rn Grea~e g~ ve iPs asmall _ . . DE c jf ,yq{, . w,v„q,: a 1998 studv cmng ~~'\ jxs a: ~ bne, ' ue ot nver= • Jo~- ! ouii=' ~atei jiosi= cilies ' • dmile, _ i~~~~r~-I . . puplie ~ . ~ - I vote it dmm,". .~ John B. BahoY= eft~ tlie top'post ~ h Crty Council? ~ ~ ed withia l$ e#tend tti'ev I tain„giiEter ates befo$~ ~t torm sysCe~ g ~iher liiea re'ased 'str~~E i• -; r•>~r Y veq the skil] pf ^~r~ s v+ wi~vne wiie.L'da+ ~ ;,, come'~. , ~ epmg dQe'_sn t "NtinB ~f us'really realized th~'t Cs sd'c}~ a's pil th~ accamUlated 'waste on oui ~ - and enYi;on , stiee['s was d~rectlypolluting'our~ ~ asmgly 5ee it oceans he said: "It s@ems.logical~ ~ ~- oIs ui Iighting now, tiut we didn'~t think 8bout if " ~ fi4e oT'16years ago; ~ ~ ~ sAn~'elesIie- " TiinesBtafJwjiferT~n¢Bijrgdttd.. - ~ ~ l~ty Corit roI cofi.tnbutedtptilisTrport. ~ ~ ~ ~ ~ reaching+plan ' ~ . n ttie LOS Ah ~ `~ ~. un.avuucia.piU-,IL'dT1Ilf1][Q_.;. ' As tfie federal govemment in-' _ ~f '/ ~ . ~~(1~e1'y RGSi11~.S for`S'~YUrday~ Sep(. 2z,. 300i ~ ~ ~ ~ S~u~atiotfo PJog` ~, ' . ' . ... h1e6a.ryamber~aBWi ~ ' . 41&~835-01=1VIega SZ ~ - : . Jackpo~ $26'm'illion ~. ~ ~ ~ . ~antas `l~va* ~ 52~3439 ~.. ~. . .. lla ~,'lbSF~ ~-~-6 ` . . . . D I~D~rb~ ~ . ~d)' Bi~ BeR - > . . (8) Gorgeous George . .. (8) Whirl t~Vin , .. - _ - Race~~'xne 1 A3.7D -i.' ~ ResuNs on the ir~tgfri,et: ~ - jvww,latih~es.cromJe~rtrds/lot[ery~ . ~ ~ - ~eneia~l informa}lori' _~ . ~800).56&83;9 :. . . . . ~ (Pesdhs fim aieil~le at ihis number)- ~, ~ - ~ ~ ~ ~..' . . . ~ KriStar Enterprises lnc., ffie Manufacfurer of: , ,x, '^` ~ l5 PKOUD TD ANNOUNGE- ~ fOSS/L f/L TER~ CATCH 6ASi N ~ _ MODEL FB-24 ~ ~ ~ ' ( ` 1 r r 1 L~ r r r~ r DESIGNED FOR USE IN AREAS WITH SHALLOW COVER: SERVICE STATIONS LOADING DOCKS FAST FOOD RESTAURANT DRIVE THRU AREAS FEATURES: - ~ DURABIE ONE RIECE FIBERGLASS CONSTRUCTION FOR EASE OF INSTALLATION ~ MAY BE USED IN AREAS WITH MINIMAL COVER OVER OUTCEf PIPE TRAFFIC LOADING ADA GRATING OPTIONAL DEBRIS SUMP FILTER WILL NOT IMREDE INLET HYDRAULIC FLOWS eaa PROVIDES THE SAME HIGH REMOVAL RATE OF HARMFUL PEfROLEUM HYDROCARBONS ACTNFllRIC1AlAI FlICC!! F//TFR~IIFCI(:N ~ . Graie (iemwaCle Ftl1E Me0'~um Retaine~ $c ~_-- . -' - . _ ~a , • -. 'Min. 6' DPa „ KR/STAR fNTERPR/SES, /NC. ~ ~ P.O. Box 7352 ~ Scnta Rosa, CA 95407 (800) 579-8819 / (70~ 524-8186 Fax ~a~O ' I I u ~ `J ' ~ IJ , . . '1 ' 4', 6', or 8' B 1 i ~ ~, LOW FLOW (FILTEREDI . r- GRATE & FHAME GRATEIADA) ~ 6' itl r~ / ~;i?' ~ FlLTER ~ _~ . MEDIUM 14', 6' Oq 6") OUTLEY PIPE - LOW FLOW~(FILTEAED) SECTION VIEW FOSSfL FILTERr"" MODEL FB-24 CAl`CH BASIN (WITH BOTTOM OUTLET) KriStar EMefprises, Inc:, Senta Rosa, CA IBOO) 6738879 ~ U.S. PATENT NO. 6,720,574 ,a~ NOTES: 1.. Catch basiMfilter body shell be one piece cons[ruction. molda8from petroleum msistant fiberglau which meets or exceeds PS 15-69. ' 2. Grate and fwme shal~ be fabricsted steel, hot dipped - galvanized in eccordance wkh ASTM A-723., 3. Grete shall have maximum spacing between bearing bars ~of 1/2' in acrordance witb ADA requirements and shali be ---trted with lockirg bolts. rta shail be designed for H20 wheel loading. er screen and screen frame shali be stainless steel ' pe 304). :ch basin may be speciied wRh 4'~ 6', or 8' Aottom ~- let. er meAivm shall~be Fossil Rock"', installed and intained in acrordance wiNi manufacturer ommendations. . - FILTER TROUGH STAINLESS STEEL SCREEN STAINLESS STEEL SCREEN PR4ME GRATE. FAAME 'PILI HEIGHT S GflATE FFiAME. ~ GALV. STEEL - _I -fl 7/4' X 1 1/4' X i/4'1~ '~ ' i ~ ~ LOW PLOW ~ ffiLTERED) ~ I ~ 1 , ~ fIL7ER TROUGH .REMOVEABLE SCREEN ~ ~ GRATE LOCKING BOLT R) STEELANCHOR ~ ~ ~ 13l8' X 3'1 1 1f2' HIGH ROW iBVPAS5) INNER WALL SCflEEN SUPPORTS 24' Zp- ~ HIGH FLOW ~ ~ (BYPASS) 14' LOW FLOW ~ . . _.- . ._...~~.IFIl7ERE0)__.._ . . 5' IMin.{ . 1T -f ~ FIITER MEDIUM ~ o-r- (FOSSIL ROCK"'1 OPTIONAL SUMP 15EE NOTE 10) TOP VIEW (GFiATE NOT SHOWNI C~RP.TE > _.. ,~.• ~ ~•i ~G •'•::;::.~. : BACK PILL ~~`~~~~',,}.~.:'~ OUTIFf PIPE ~ ~ FlL7ER TROUGH d~ CATCH BASIN ~ REMOVABIE FlLTER MEDIUM flETAINER SCREEM • ~ ~,~_~ F(L`[ERMEDIUM • • • • COPAAINMENT . .". '. .' ~~.' . ~~ ~~ ' ' ' .-.-. . • O i - • - _ . . _~_~LONCNETE ~ - • MIN.6S DEEP -~i'~---- _ . _ . a. . 1~X^ V. • - ,-i` ~ ~ ~ - ~? y~.-. '. . .. SECTION VIEW ~ FLEXIBIE" ICATCH BASIN/FILTER BODY) CONNECTION ISEE NOTE 71 NOTES: t. Catch Basin~iter body shall be one piece consVUCtion moided irom Rberplass wbich meets or exceeds IPS 75-691. 2. Grete end irame sha0 be fabdcated steel, galvanized in accordanca wit7~ ASTM A-123. ~ . ~ 3. 6rate shatl bave maximum spaci~ of 1!2'-be[ween bearinp bers In eccordance with ADA requirem~ss and ~ shall be secured with lockinp bohs. 4. ~rete she0 be desipned (w H20 wheel badinp. 5. Rker screm end saeen freme shail be stainlesa steel (Type 3041 atl screens shall be 8 mesn. ~ 8. Catch Basin may be specified wRh single or muhf0~e ~~ outtet ppes.l3'. 4', or 6' de.l• ~ 7. ~ Pipe to inlet connection shail be water t~pM and flexible con/orminp to ASTM C-923. ~ 8. Riter medium shall be Fossr7Rack,° installed and maintained in accordaue with manutaMUrer recommendations. 9. A minimum cover of 6' ia required over ouUet pipelsl. )0. Cetch Besin may be spec~ed wiffiout sump area. FOSSJL FILTERT"" MODEL FB-24 CATCH BASIN (WITH SUMP) KriStar Enterprises, Inc., Santa Rosa, CA (800) 579-8879 '~ . U.S. PATEM NO. 5,720,674 \~~ BYPASS NOTES: CARTpiDGE LID . ADSORBENT FRL ll .RTHIDGEINLET ..- rneMETER, OPEN BOTTOM PVC CARTRIDGE ~ ISEE NOTESF ~ CARiRIDGE OUTLE ' (8'-~IAMEfE! I ~ I ' ~ BOTTOM SCREEN I I_i/ o~~ { ~ DIAMETER) ' f_ 1 ~ ~ ,ortn uu ~ i om, r ~ r ~ ~ r- 1. Fker body and cartridge assembly shall 6e construc[ed Trom ~ petrolevm resistant CWC'plestfc. ' ~ . 2. Screens sAall be steinless steel (fype 3041. . ~ 3. FOSSIL TEE'~ may ba insta0ed into new or existing ~retro-fiq ~ oil/watar separator tanks. Re/er to installalion detals (sheet 2). 4. Fker medium shail be FoslARock "' insta0ed in cartridge to adsorbent fitl line aM maintained in acwrdance with manutacturer's recommendatiom. ~ - 5. Reter to manufacturer's recommendations for maintenance~program. BYPASS FOSSIL FILTERT"' FOSSIL TEE FILTER (MODEL fF-T106 - 10" x 6") INSTALLAl"ION DETAIL (SHEET 7 OF 2) ~~ I. KriStar EMerprises,~lna; Santa Rosa, CA (800) 5738819 PVC FILTER BODY 110' DIAMEfER) TOP VIEW 16' DIAMETERy ~ '- ' ~ C NOTES: 1. FOSSIL TEE° is designed to be instalied into rrew or existing . (retro£U oil/water separetor tanks. ' 2. Connect to existing outlet pipe with PVC or rubber (Caulder) . couplings. 3. Locate FDSSIL 7EE"' below eccess cover fa maintenance - eccess. Cartridge must be removed ffirough top opening. - 4. Additional bracing may be required, depending on application. 5. ComD~~ance with confined space laws is recommendeC when instalfing or maintaining FOSSIL TFE.° ' . 6. Flter medium shali be fosu7Rock,'tl~n;tallad and maintained in accordance with manufacturei recommendations. DIMENSION CHART A6SORBENT PILLOWS 10Pf10NAL1 TOP VIEW HIGH FLOW OUTLET PIP MIET PIPE OIW SEPARATORTANK (TYPICAl1 ~ SEE N( BRACE TO V ISEE NO'. FOSSIL FILTERTM FOSSIL TEE FILTER (MODEL FF-T706 - 10" x 6") INSTALLATION D~TAIL (SHEET 2 OF 2) ~~(/~ ~.~ KriStar Enterprisas, Inc., Sairta Rosa, CA (800)~679-8819 MODEL . A B .G._ : p . NO.- . _ FF-T108 6'~ 10' 24' 6' ~ ' '-- f , , __ '' ' __ '_ , ~ ' , r , 1-- ' r ~- ~ r ____ r~n . -. • Fossil Filter'"" PERK Fi" '" Curb Opening 5i Fr Features: vtlet (below ERK Filter'" irame) • Adds detention area to any-existing dreinage inlet tor the collection of sediment, trash & debris. • Easy to maintain hydrocarbon (oil & grease) Cilter wi(h built in "high Ilo~' byPass. • NO standing water (collected wata in detention erea slowly pen~.olates into storm drain system, leaving collected solids and otha pollutants.) .. • -Constmcted from corzosive resistant ma[erials. - • Sizes to 5t most indushy sfandard drainage inlets. POLLUT/ON from stormwafer runoff??? Fossil filter""is the SOLUl70N111 ~~~~ from the makers of `~~~~~~(~ ~~~~ ~''~~~ PAIEMPENDI~ n.,~.,.,,;..., n.~8 ss Combination Inlet 5~ ' 1 1 J ' ~ 1 ~l ' 1 , r1 I ,. GflATE HIGH PLOW FOSSIL FILTER'" /~ BYPASS PERK FILTER ~ /\ / _. ._.r-~~-ii-r~x~: ~ - . COMBINATION INLET HYDROCARBON FILTER NOTES: 7. PERK 57eei°shall be ronstructed fmm cortosion - resisiant matarials (HDPE or PVC plastic). 2. Base plate support hame shail be fabricated steel, hot dipped, galvanized in acrordance with ASTM Designation A-123. . 3. Locate base plMe support frame a minimum of 1' a6uve inlet and/or outlet pipe. . 4. Base plete support frame shail be secured to catch basin wall with a~ minimum"of four (4) i/2' diameter x 3' expansion arichors and stainless steel fType 304) bohs end washers. Seal gap between supPOrt freme end catch basin wail with expansion foam sealaM. 5. Riser Ibypau) pipe shall be WC plasnc (SDR 35) m ekher 12' or 18' diameter. Riser height will vary depe~n~q on depth of catch basin and location of outlet pipe ~~~>'- -~~-~- ~' 6. Flter me~um shall be FauDRack mstalied end mainteined (n ~ acwrdance with manufacturer recommendations. ~ //\\ ~~ OUTLET (BELOW ! \ PERK FILTEH'" PRAMEI \ SUPPOflT FRAME SEAL (SEE NOTE 21 t COMINATION INLET {Gutter/Curb Openings GRATE 6• ~ r ~ ~ r~ ~ A DIMENSION CHART MODEL NO. A B C ~ CATCH BASIN f I.D.) FF-2436PF 23" 72' - 24' x 36' FF3636PF 26' 18' - 35'x 35' HYDROCARBON FILTER DEfENTION- - "" ~ (SEENOTE3) ~~ B OUTLET PIPE BASE PLATE 'i~ . 15EE N07E 4) SIDE VIEW ANCHOR DETAIL I FO~SIL FILTERTM "PERK FilterT"" " Percolation Filter (FLAT GRATED WLET) `6~7i KriStm Enterprises, Inc., Sarrta Rose, CA 1800) 579-8819 , PATENT PENDINCa ' ,~ '~ '~ ,~ '1 ~ ~ GRA7E . Q~~Q~~~QQQQ~Q~ Q~Q \ . QOQ~QO~~~~~OQ~Q~QQQ~~pp ~~~p0~~ 00 FOSSIL PERK CURB OPENING ' .4. Base pia;e support frame shall be secured to catch basin wall whh a minxnum of four (4) 1Y1' ?ameter x 3' expansfon anchors and HIGH FLOW~ steiNess stee~ IType 3041 bohs and washers. Seal gap between ~ BYPASS suDDOrt trame and catch basin wall wkh axpansion toam sealant. ~ 5. Riser (bypassi O~Pe shall be WC plastic (SDR 35) in eitber 12' or '0n =" "~~/~` ' COMBINATIOW~MLET, ~'-' 76" dameter: piser hei htwiil va de endin oilde th of'cet'cfi - .:. 9 ~Y P 9~ a basin and localion of outlet pipe. /~ 8. Flter medium shall be Fosv7Rack° installed and maintained in .Y 1 eccordance wiih manutacturer recommendations. NOTES: - 1. PERKFihe!°shall be constructed fmm wrrosion - resistant materials (HDPE or PVC D~asticl. - ~ 2. Base plate ~suppott frame shail be fabricated rieel, hot dipped, galvanized in accordance with ASTM Designation A423. - ~ ~ . ~ 3. Locata basa plate support lrame a minimum of t' abova inlet ~ . and/w ouUet pipe. " HYDROCARBON FILTER SUPPORT FfL4ME SEAL ISEE NO7E 2) OUTLEf IBELOW PERK FILTER"' fRAMEI ~ ~ COMINATION INLET (Gutter/Curb Openings ~CUfl9 OPENING ~ ~ 6. . "~ HYDROCARBON FIITER A --~ DerermON OOOO AREA BASEPLATE nnnn~ ~ SUPPORT FRAME B BASE PLATE OUTLEf PIPE SIDE VIEW I \ ~fSEENOTE4) ANCHOR DETAIL DIMENSION GHART MODEL NO. ~ A B C CATCH BASIN ~ I.D.) fF-2436PF 23' 12' 24• x 36' FF3636PF - 28' 78' - 35' x 35' FOSSIL FILTERTM "PERK FilterT"'" Percolation Filter ! (COMBINATION INLETi `'~j2j KriStnr Enterprises, Inc., Santa Rose, CA (800~ 679-8619 PATEM PENDING _ ' ~ ' ' ~ , , '^ ~ r r L~ r r r r ~~ r Flo II~TO COnAPL1APICE. FloGard~" complies with state and federal requirements for pollution protection of drains from storm water runoff in a variey,of installations. FloGard~" captures silt and debris, as well as oils and grease from runo$ before it enters our streams and oceans. PloGard'" is suitable for use in such ' applications as vehicle parking lots, aircraN ramps, truck/bus storage yards, corporate yords, ,~ subdivisions and public streets. COMRACTORS can use FfoGard'"" during construction ro Handle sediment probiems. EASY, ECOPiOd1A1CAL SOLUTIOld. The FloGard'" design allows for installation in eit6er new or existing drain inlets. lndustry-standard sizes and shdpes are availoble for flat-grated, combination, curb and round inlet applica(ions. FloGard~" is easy and economical to install. FloGard"" uses the same effective filter medium ~Fossil Rock'"') found in ourother Fossil Filter'" products. This medium is in prefilled adsorbent pouches that are easily replaced. Additionally, the filter body is replaceable should damage occur during usage. lV6~IPITEIVAPICE PttOGR~111S. Product discounts are available with the purchase of a comprehensive mainfenance package. PloGard'" - Another economica) pollution. solution from the makers of Fossil Filter""I U.S. FATENT PENDING TM ~ ar Economical Storm Drain Pollution Solution ~~ ,~ mziry repeceooie rvwoowr aesign miovn prefilied Fossil Rak° br eosy replacement povchesoRerefleaire olfiltercomponen6. remom~ o( oil and - . ' greose. '. r r ~ LJ r ~ r , r ~D~~ard~ HIGH -ncP in• Fossi fiOCK" Boom! (hydrocarbonr¢ tluring ~ighest il Stainlesc eleN 6UOp011 ~lBT! (earyinstellatior wi~houl anc~onr lo catch basin) unersupporth (durabie suppor marimvm weigh crollectetl poilut[ High tenWk co support phlas ~edtletl beA su{ retalns liner sire 6h3pe when full; PATEM PENDINQ The unique `patent pending" desig~ oE the FloGard'" High Capacily catch basin insert offers a removable "trap" that ~etains Floatables during high flows. The solids holding capaciy of Ihe FloGard'"' High Capacityinsert will vory by model. For example, the 24"x 24"x12" model will hold approximately 1.67 cubic feet of debris, while a 36"x36"x36" model will hold up to 13.43 cubic feet. ~movabla tlebMa trdp :taNS floateCles during )h flows) )SSIL ROCM' Ilow (hydracabon noval tluri,g bw flows) ~ ~~ ~~ ill~ nol impetle arJmum design ilows) ipaceaWe flner Ilner Hectivay collects d~meM, deDria entl sn) 'Refar to spec~~atio~ chart (or aveilable sizes Go with ~"The Fb': FloGard"" High Capaciy is recommended For ~~ areas with kigher.fhan normal amounts of sediment and debris and mode~ately high levels of peiroleum hydrocarbons. 6camples of appropriate opplications are public sheets, equipment sforage and/or maintenance yards and industrial facilities. For areas where petroleum hydcocorbons (oil and. grease) are a concern, the floGard'" High' Capacity cotch basin insert may be speciFied with Fossil Rock° filter medium in easy to replace °clip in" pouches. CAPACITY Basin Insert L 1- ' ' ' ^ ~^_ ' , , ' . , - ' '~ ' r ~ ~ I ~~~T~ ~ TM O ~~ The Economical Storm Drain Pollution Solution FloGard"" has made a presence in Dana Point, California: A 3 monih old installation of 150 Filters in the city's public . storm drains resulted in the collection of over, l ton of dirt ~ and debris. Plus, the (ilters colledeil peholeum hydrocarbons , (oils and grease). If no(for these filters, all the collected-dirf, _ debns and hydr«arbon pollutants would have spded,up m.,., _, . the Pacific Ocean. Pollutants once considered as`~iarm~ess solids and debris are now considered as more °visible" pollutants. For example, organic debris blown into gvtters during landscape maintenance is now considered a pollutant. Fertilizers, peslicides and herbicides eventually could reach waterways and harm aquatic life. Even common debris such as cigareMe butts seem harmless, but contain tars'and nicotine, which also are pesticides. What once seemed harmless and an almostnatural occurrence as runoff debris; has been (ound to be potentialiy harmful to our environment. 1Nith produds such as the FloGard'"", we may some day eliminate all pollution (rom storm rono(f. Low cost installation and low cost maintenance make the . PloGard'" the economical siorm drain pollution solution. Go wii "fhe F r ~- . • .• OO 7999 2001 KriStar Enterprises, Inc. ~ ~Fosul fiherT", FbGardT'" and ihe Dinosour choracters are registered hademarks of Kri5lar Enrerprises Inc.. . :.:...;: - GiSNr Enierprises; Iric. • P.O. Box 7352 • Santa Roso, CA 95 407-03 5 2 •%i: 806579-881R+~FJd(:~ 707324$T86~ • vnvw.kris~occan ,~~ '- ~ r_ , , - ' , , , ' , , ' , ' '_' r I '- ' ' STAINLESS S7EEC SUPPORTFRAME CORNER t UPPORT ,tACKETS B NEOPRENEGASKET J ~ (TWO SIDES) DURABLE WOVEN MESH FlLTER 80DY REPLACEABLE ADS...,.,..~r ~~~ ~ .., SILT AND DEBRIS . CONTAINMENT ARFJ 99~ H€PIACErtBLE . ~ADSORBENT-FILLED ~ . POUCHES SECTION VIEW FILTEA BODY ATTACHMENTSNAPS B `\ ~~~'~=~~~.y B ~ ~ ~ / ~ FOSSIL FILTER~""' FLO~GARDT"" CATCH BASIN INSERT . ISHEET 1 OF 21 ~ KriSter~EMerprises, Inc., SanU Rosa, CA 180~! 5~9-8B79 . PATEM PENDING REPLACEABLE ADSORBENT-FlLLED POUCHES NOTES: i. fb-Gard "'Pilter body is pretabricated from polypmpylene woven monofilement geoteztle. ' 2. All metal components shall ba sta(nless steei IType 3041. 3. Reter to sOP~~cadon chart for catch basin and fiiter sizing. 4. Flter medium shail be foasBRock,"~ instnlled erd maintained in ~ accordance with manufacturer recommendations. ' 5. Pefer to Manufacturer's recommendations for maintenance ~ program. 6. FlrGard"'inserts may be instelled (without edsorbent pouchesl ~ during course of constrtiction as a sedimenTation contmi dev~ce. Aher construction, remove sedment and instell adsorbent pouches. APPLICATION CHART~ MODEL NO. ~~nlet I.D. Carata O.D. COMMENTS PF-16D 16' x 16' 78" x 18" - GRATED INLET ~ FF-i8D 78' x 18' 20' x 20' GRATED INLET ~ FF-1838SD 16' x 36' ~ 18' x 40' GRATm INLET FF-7636DG0 78' x 36' 18^ x 40' - COMBINATION INIET FF-24D . 24' x 24' 26' x 26" ~ GRATED INLET FF-2436D 24' x 36' 24" x 40' GRATED INLET FF-RF24D - 24' Dla. 25' Dia GIflCULAR INLET ~ FF-24DG0 24' x 24' 18' x 28' ~ COMBINATION INIET PF-2436DG0 ~ - 24' x 36' 24' x 40' COMBINATION INIET 9FFlo-Gard"' Filter inserts are designed to frt catch basins with approximate dimensions shown. ~ ° ~ MODULAR DESIGN FOR EASY REPLACEMENT OF FILTER COMPONENTS TOP VIEW ' NOTES: ,~ I ' ~ ~ ~ ~ ~ ~ ~ ~ ^ ~ L INLET ^^•" 7. F7o-Gard'" Flter botly is pretabricated from polypropylene woven 'monofiiement gaoteMile. 2. All rtretnl componenta shall be stainlws steel (Type 3041. 3. Re(er to applicntion chart Tor catch basin and fiher sizing. 4. Fiter medium shail be Fossr7Rock° ins[alled and maintained in accordance wkh menufec[urer ~ecommerWations. ~" ~ 5. flefer to ManWeMUrer's racommendations for maintenance ~ progrem. ' . - 6. f7o-Gard"' inserts may be installed withouc adsorbent pouches during course oi construc[ion as e sedimentetion control device. Ahu wnstruction, remove the sediment and install the edsorbenfpovches.. F70-GARD"' INSERT E APPLICATION CHARn CATCH BASIN APPLICATION CHART* MODEL NO. . ~^1e~ ~-D. Greta O.D. COMMENTS FF-16D ~ 16' x 16" 18' x 18" GRATED WLET FF-78D ~78' x 18' 20" x 20' GRATED INLET FF-1836SD 78" x 36' 78' x 40" GRATED MLET FF-1836DG0 18' x 36' 78' x 40' COMBINATION INLET FF-24D ~ 24' x 24' 26' x 26' ~ GRATED INLET FF-2436D 24' z 36' 24" x 40' GRATED INLEf FF-RF24D 24" Dia. 25' Dia. .- CIRCULAfl MLET - FF-24DG0 24' x 24' 18• x 26' COMBINA710N WLET -FF-2436DG0 24' Y36' 24' x 40" COMBINATION INLET '~' Flo-Gard Fiiter"' inserts are designed to fR catch basins with approxunete dimensions shown. . . FOSSIL FILTERT"' FLO-GARD T"" CATCH BA~IN INSERT INSTALLATION DETAIL (SHEET 2 OF 2) ~~ KriStar Enterprises, Ine., Santa Rosa, CA (8001 57&8819 PATENTPENDING ' ~ , 1 ' , MANHOLE GASKEf ~J ~J ' ~ ~ ~ ~ t ' ~_ W (CURB OPENING) CATCH BASIN . - CURB OPENING e . . a.. (SEE NOTE 8) GUTfER ~~ ~ FLOWk1NE fILTEp BODY ~ ~ - FILTER ~ ~ ~ ~ ~ , BASKET FOSS~L ROCK"' ' FlLTER ~ MEDIUM POUCH e SIDE VIEW GUTfER FLOWLINE z•, ._ . _ _ . ANGHOH DEfA1L 3I8' X 3• FILTER ~CHOR BOLT BODY (3 PER SECTION) NOTES: 1."fio-Gerd"fiRer body shail be manufectured from petroleum reststant fiberglass which meets or axceeds ' PS 15-69. ~ ~ 2. All metel components sMell be stainless steel Rype 304~. 3. Removeeble fiher basket shall be consLUCted from - - durabie potypropYtene woven morwfilament. ' geoterztile. . ' 4.'Ho-Gaid' fiiter body shall be secured to catch basin wall with expansion anchor bdq and washu. ISae detaill 6. Ho-Gmd' inserts are avaiWble in 24' or 30' length ~ sectlons arM may be installed in varioue combinattons - ~(end-to-ondlto frt most catch basin widths. ~ 6. fllter basket may be~removed Mroueh~ curb opening for ease of maintenance. ~ 7. Fker medium shell be. Fassd Rock,° in dsposable pouches, instatled end maintained in accordance with manutacturer recommendations. - FOSSIL FILTERT"' FLO-GARDT"" CATCH BASIN INSERT (CURB OPENING INLEI) KriStar Enterprises, 4ic., $aMa Nata, CA ~800) 579-8879 . PATENT PENDING ~~ ' ~ '-r r ~ TM ~IGH CAPACITY ~/!~ Catch Basin Insert The most effective storm drain filtrution device nvailable for use in . high debris and hydrocarbon areas, such ns public streets, industrial fncilities and others where trash, debris nnd oils/grease are a mnjor concern: -~~°~ ~°~°--~`~ ^ "Clip In" FOSSIL ROCK'" Booms (hydrocarbon remove 1 during highest flows) 1 Stainless steel support (rame ~. ~ ~ (easy installation ~ . without anchoring to catch basin) \ , r r r r r Liner support baske (durable support for ma~cimum weight of collected pollutants) High Eensile corner support cables (adcled load support that retains Iiner size and shape when full) r r PATENT'PENDING KriStar Enterprises, Inc. P.O. Box 7352 Santa Rosa, CA 95407-0352 888-579-8819 - FAX 707-524-8186 :movable debris trap ;strains floatables iring high flow periods) )SSIL ROCK'" Ilow (hydrocarbon moval during low flows) gh tlow bypass ill not impede - ycimum desig~ flows) :placeable filter liner ffectively collects diment, debris and ish) ~fo` *Refer to specification chart for available sizes. ' ' - . REMOVEABLE - FIL7ER BAG WI7H - ~ FLUME (TRAP) ' . ' ' ! DEBRIS 7PAP ~ AND BYPASS ~ 1HDPEPLASTIC . ~ OR FIBERGLA551 ~ ~ ~ . ~ ^ - NOTES: rcH cn , . BASIN ~ . . - . ' ' ' ' . 1. Ao-Gard"~Nigh Cepecity inserts are avarlable in sizes to (it mosf industry- . ~ - ~ standard catch basins fsee specifier chart). Custom sizes are available. ~ 2. Fllter suppart flanges shali ba constructed from stainless steel (Type ~ 304) Debris trap (flume) shail ba constructed from either petroleum ~ res(stant fiCe,glass or HDPE plastic. . 3. Fiker liner support basket shall 6e constructed from a biexial geogrid ' with e minimum ultlmate~tensile strength of 900 x 1400, as tested in . ~ . ~ , accordance wrth ASTM D-4595. 4. insert liners are available in standard depths of 12 24 or 36' ~reter ~ _._ , n, F . lo c~~acity~~rfhar,tl._Cus[om lirter depihs may be spea(~ed.>,,;r-:~~-, ,_. -. SUfRAMEJ TOP VIEW - ~ . IGRATE NOT SHOWN) CAPACITY CHART . ~ ~r ' ~ ~ ~ ~ SUPPOfiT FRAME 3' MI~ ~ BYPASS (4 SIDEDI 4" MIN. ~ 11,. ~ ~_ CATCH BASIN FILTER LINEfl MODEL NO. ' Inlet Size - Liner Depth Stora9e Capaeity (cu. k.) Clean Flow Rete' • (BPm) FF-2424HC 24' x 24" 12" 1.67 470 • " 24' x 24' 24' 4.18 974 " - 24' x 24' 36" 6.69 1357 FF-2436HC 24' x 36' 12' ~ 2.55 641 " ' 24'x36' 24" 8.38 7zp7 ' " 24'x 36" 36' 10.20 1767 FP-3636HGG0 36' x 36° 72' 3.36 77p ' ' 38' x 36" 24' 8.39 1402 ~ ' 36'x 36". 36" 13.43 2032 ~ Storage capaciry retlects mezimum solids collection prior to impedin9 bypass. 'x' * Flow rates are-"caiculatad clean fiow rates" besed on liner material flow rata of REMOVEABLE ~0 gpm/sq. ft. . . FLUME (fRAPI <<ecommend applying fector of .25 to .50 to Flow rates to allow for sediment (HDPE PLASTIC antl debris) OR FIBERGLASS) ~ . , GRATE ~ - PILTFA LINER ~ ~ SUPPORT BASKEf , '~ ISEE NOTE 31 ~ ~ (SEE NOTE 4) 2" MIN. --+ ~`_~ , r-- SIDE VIEW FOS51L FILTERT`" "FLO-GARD~~TM HIGH CAPACITY CATCH BASIN INSERT KriStar Enierprises, Inc., Sanca Rose, CA (800) 579-6819 . . PATENT PENDING ~~ ' - ~_ 1! . ' ( 1 '~ . 'I ~~ _ (1 '. DIRECIION OF FLOW N Cl~~ O ~ • e d ~ .~ e •. • . . ..~ a~. °~d ~ a ~ FILTER BODY d s Q• J \ ' ~ i TYPICAL TRENCH DRAIN INSTALLATION NOTES: ~ . F7o-Gerd~Fltar body is prefabricated irom poiypmpylene ~ woven monofdament geoteMte. 2. PJI metal componenb sliall be s[ainlass steel (Type 304~. 3. Flter body shatl be secured to Vench drain or catch basin waA with a minimum of three (3~ expansian anchor balts -(1/2' x 3'1 eM steinless steel boits and weshers. ~ 4. Fker maJum shail be FossAROt,t installed and . maintained in accordance with manufacturer recommenda[ions. RWL - ~ - INLET PIPE , . -IFROM RAIN WATER ~ LEADER-OR AREA DMIN) BLACK TOP OR CONCRETESURPACE GRA7E CATCH - BASIN ~ 12^ ~ FOSSIL FlLTER"' FLO-GARD"' ADSORBENT POUCHES CATCH BASIN CROSS SECTION WIT71 qA1NWA7ER LEADER (RWW SIDE VIEW FOSSIL FlLTER'~ FLO-GARD"' WITM " REMOVEABLE FILTER BASKET ~ ADSORBEN POUCHES TRENCH ORAIN CROSS SECTION - WffH F-0SSIL FILTER'" RO-GARD° FOSSIL FILTERT"' FLO-GARDT"' SUPPLEMENTAL FILTER (TRENCH DRAIN) Kr(Ster EnterprLses, Inc., Senta Rosa, CA (8001 579-8819 PA7ENTPENDING ~Y9~ FLO-GARD"' FILTER INSTALLED Jtl~ I IUIV ' I ~ GENERAL SPECIFICATIONS:FOR FOSSIL FILTER~ FLO-GARD STANDARD AND FLO-GARD HIGH CAPACITY ~ ' CATCH $ASIN INSERTS . Scope: ' Tfvs specification describes a Catch Basin Filtration Device that removes sediment, debris, trash and petroleum hydrocarbons from water flowing into the drainage inlet ~ during low flows (Srst flush) without impeding the inlet's maximum design flow. Hydraulic bypass calculations shall be supplied upon request. '` The filtration device shall incorporate a silicate adsorbent filter medium capable of , " collecfing and contairung non-soluble pollutants mc~uding, but not lunited to; peUroleum _ ~ hydrocarbons (oil and grease). Filter medium shall be contained in separate removable containers that can easily be replaced witbout removing the fiher liner. Filtration device shall not rely on collected sediment, debris, trash or filter liner as the medium for ' hydrocazbon collection. High capacity filtration devices shall be supplied with removable debris trap for the ~ retention of floatable pollutants during high flow periods: Material Properties: ~ Filtration device support frame and hardware shall be manufactured from Type 304 ( stairiless steel. It shall be designed to support maximum anticipated loads from the ~ collected pollutants and water, without anchoring to inlet. Structural calculations or laboratory tests shall be su lied u on re t pp p ques . Filtration device body, debris trap and related support components sball be constructed ~ from corrosion resistant materials (HDPE plastic, petroleum resistant fiberglass or Type 304 stainless steei). r Device liner shall be made from woven polypropolene monofilaznent geotextile with a i l flo ma~t mum c ean w rate of 140 gpm/ft r Filter medium shall be hydrophobic silicate adsorbent material treated to attract and retain petroleum hydrocarbons and other non-soluble pollutants. It shall be non- ~ biodegradable and non-leaching and contain no liazardous ingredients as defined by the U.S. Environmental Protection Agency (EPA), U.S. Occupationat Safety and Health Administration (OSHA), and the World Health Organization (WHO). ~ Installation: ~ Installation of filtration device shall not require extensive modification of tl~e catch basin and shall be performed by a manufacturer-appmved installation contractor. Installation contractor shall be licensed and insured in accordance with agency requirements. ~ ~ ~~~ r _____ . ' ' PAGE 2 - General Specifications (- Filtration devices installed into grated, or combination grate with curb opening inlets , shall be self-supporting and installed without the use of anchoring devices. ' Devices for curb opening inlets (no grate) shall have a removable filter basket that can be removed without entering drainage inlet. Device shall be secured to inlet wall, across and beneath curb opening; using corrosion-resistant anchors in accoidance with manufactuter recommendations. The use of chains or cables shall not be allowed. All anchoring devices shall be installed within the interior of the drainage uilet. Anchoring devices ~_ shall not be installed outside the drainage inlet in azeas subject to foot or vehicle tr~c. Filtration devices shaU be'installed in such a manner as to duect all flows into the device. '' ' Distance (gaps) between the inlet wall and the device shall not exceed 1 inch. Gaps of less than 1 inch shall be sealed with a flexible weat}~erproof sealant, as approved by agency. ~ Installation contractor shall supply agency with an installation record, denoting the date of installation, drainage inlet location, type o€drainage inlet and type and/or size of filtration device. , ' . f ' '^ , (Rev Ol/Ol) ~ ~ ~ r r ~ . ~ ~~~. r _ __ _ HING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL August 1997 (DRAF°I') ~ ~ ~ ~ Prir+ted on Reryc(ed Paper _ ~ \r King County .. _ Department of Natural Resources ' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE OF CONTENTS CHAPTER 5 FLOW CONTROL DESIGN CHAPTER 6 WATER QUALITY DESIGN Section 5.1 Roof Downspout Controls in 5-3 Section 6.1 Water ~uality Menus 6.3 Subdivisions Section 6J.1 Basic Water Quality Menu . 63 Section 5.1.1 Downspout Infiltration 5-5 Section 6.1.2 Sensitive Lake Protection Menu 6-5 Systems Section 6J.3 Resource Stream Protection Menu 6-9 Section 5.1.2 Downspout Dispersion 5-8 S2ction 6.1.4 Sphagnum Bog Protection Menu 6-10 Systems Sectlon 6.1.5 Fligh-Use Menu 6-13 Section 5.1.3 Perforated Stub-out 5-10 Connections Section 6.2 Generai Requirements tor WQ 6-15 Facilities • Section 5.2 Flow Control BMPs 5-11 Section 62.1 Water ~uality Design Flows 6-15 Section 6.2.2 Sequence of Facilities 6-16 Section 5.3 Detention Facilities 5.75 Section 6.2.3 Setbacks, Slopes and 6-18 Embankments Section 5.3.1 Detention Ponds 5-15 Section 6.2.4 Facility Liners 6-20 Section 5.3.2 Detention Tanks 5-28 Section 6.2.5 Flow Splitter Designs 6-26 Section 5.3.3 Detention Vauits 5-32 Section 6.2.6 Flow Spreading Options 6-30 Section 5.3.4 Control Structures 5-35 Section 6.3 Biofiltration Facility Designs 6-35 Section 5.3.5 Other Detention Options 5-46 Section 6.3.7 Basic Biofiltration Swales 6-35 Section 6.3.2 Wet Biofiltration Swales 6-49 Section 5.4 Infiltration Facilities 5•47 Section 6.3.3 Continuous Inflow Biofiltration 6-52 Section 5.4.1 General Requirements for 5-47 Swales Infiltration Facilities Section 6.3.4 Basic Filter Strips 6-53 Section 5.42 Infiltration Ponds 5-54 Section 6.3.5 Narrow Area Filter Strips 6-60 Section 5.4.3 Infiltration Tanks 5-57 Section 6.4 Wetpool Facility Designs 6-63 Section 5.4.4 Intiltration Vaults 5-60 Section 6.4.1 Wetponds - Basic and Large 6-63 Section 5.4.5 Infiltration Trenches 5-62 Section 6.42 Wetvauits 6-75 Section 5.4.6 Smail Infiltration Basins 5-63 Section 6.4.3 Stormwater wetland 6-80 Section 6.4.4 Combined DetenGon and Wetpool 6-86 Facilities Section 6.5 Media Filtration Facility Designs 6-93 Section 6.5.1 General Requirements 6-93 Section 6.52 Sand Filters - Basic and Large 6-94 Section 6.5.3 Sand Fiiter Vaults 6-113 . Section 6.5.4 Linear Sand Fiiters 6-119 Section 6.5.5 Leaf Compost Filters (LC~ 6-124 Section 6.6 Oil Control Facility Designs _ 6-127 Section 6.6.1 Catch Basin Inserts 6-127 , Section 6.62 Oil/Water Separators . 6-133 ~~~ ~ Sudace Water Design Manual ~ , August 1997 Draft ~ KING COUNTY, WASHINGTON,.SURFACE WATER DESIGN MANUAL CHAPTEIZ 6 WATER QUALITY DESIGN This chapter presents the King County approved methods, criteria, and details for analysis and design of water quality facilities pursuant to Core Requirement #S, discussed in Section 1.2.8, and Special Requirement #5, discussed in Section 1.3.5. Chapter Organization The information in this chapter is organized into the following six main sections: • Section 6.1, "Water Quatity Menus" (p. 6-3), details [he area-specific water quality menus referred to in Core Requirement #8 of Chap[er 1, and the High-Use Menu referzed to in Special Requirement #5, also in Chapter 1. ~ • Section 62, "Generat Requiraments for WQ Facilities" (p. 6-IS), presents general design requirements and details pertinent to all water quality facilities. • Section 6.3, "Biofiltration Facility Designs" (p. 6-35), presents the details for analysis and design of biofiltration faciliues such as biofiltraHon swales and filter strips. • Section 6.4, "Wetpool Facility Designs" (p. 6-63), presents the details for analysis and design of wetpool water quality facilities such as wetponds, wetvaults, stormwater wetlands, and . combinations of these facilities with detention ponds. _ • Section 6.5, "Media Filtration Facility Designs" (p. 6-93), presents the details for analysis and design of Filtration facilities such as sand filters and leaf compost filters. • Section 6.6, "Oil Control Facility Designs" (p. 6-127), presents the details for analysis and design of oil control facilities such as catch basin inserts and oiUwater separators. Required vs. Recommended Design Criteria . ~ ~ ~ ~• . Both required and recommended design criteria are presented in this chapter. Criteria stated using "shall" or °SnusN' aze mandatory, to be followed unless there is a good reason to deviate as allowed per t6e adjustmentprocess in SecHon 1.4. These criteria ue required deslgn criteria and generally afFectfacility perfonnance or critical maintenance factors. Sometimes options aze stated as part of the required design criteria using the language "s6ould" or "may." These latter criteria aze really recommended design criteria, but aze so closely related to the required criteria that they aze placed with it. In some cases recommended desig~ features are presented under a sepazate heading in the "Design Criteria" sections. Use oF Chapter 6 Figures: The figures provided in Chapter 6 illushate one example of how the WQ facility design criteria may be applied. There may be other engineering solutions that also meet the design criteria. Those options are also allowed unless it is the judgment of DDES that the opdon has other problems that rendei it a poor engineering choice. Although the figures are meant to illustrate many of the most iasportant design criteria, they may not show all criteria which apply. In general, the figures in Chapter 6 aze not used to specify requirements unless they aze indicated elsewhere in the Manual. ~,~~ Sufface Water Design Manual Au~ust 1997 Draft KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 6.3 BIOFILTRATION FACII,ITY DESIGNS This secpon presents the methods, details for analysis, and design criteria of biofiluatlon swales and filter strips. Included in this section are the following specific facility designs: • Basic Biofltration Swales, Secdon 6.3.1 • Wet Biofiltration Swales, Section 63.2 • Continuous Infloiv Biofiltrauon Swales, SecHon 63.3 • Basic Filter Strips, Section 6:3.4 ~ Narrow Area Filter Strips, Secuon 63.5. The information presented for each Facility is organized into the following two categories: 1. Methods of Malysis: Contains a step-by-step procedure for designing and sizing each facility. Information presented in the procedure is based on available literature, but clarified or modiFed where deficiencies were identified.15 2. Design Criteria: Contains the details, specifications, and material requirements for each facility. 6.3.1 BASIC BIOFILTRATION SWALES A biofiltration swale is an open, gently sloped, vegetated channel designed fot treatrnent of stormwater (see the detaiis in Figure 6.3.1 A ttuough Figure 63.1.E beginning on page 6-46), The primary pollutant removal mechanisms aze filtration by grass blades which enhance sedimentation, and trapping and adhesion of pollutants to the grass and thatch. Biofiltra[ion swales generally do not remove dissolved pollu[ants effectively. Applications and Limitations A biofiltration swale is designed so that water will flow evenly across the entire width of a densely- vegetated azea. A swale can be designed for both treatment and conveyance of onsi[e stormwa[er flow. This combined use can reduce development costs by eliminating the need for sepazate conveyance systems. Biofiltration swales aze best applied on a reladvely small scale (generally less than 5 acres of impervious surFace). , T6ey work well along roadways, driveways, and pazking lots. Swales aze more costly to apply in situations where the swale channel would be deep; in deep swales, self-shading can inhibit the necessary grass growth, resulting in poor pollutant removal perFormance. Some specific consideradons for Biofiltration swale applications are as follows:. •-A biofiltration swale should not be located in a sfiaded azea. For healthy grass growth, a swale should receive a minimum of 6 hours of sunlight daily during the summer months throughout the length of the swale. • To maintain healthy grass-growth, a swale must dry between storms. It should not receive con6nuous base flows (such as seepage from a hill slope thcoughout the winter) or be located in a high groundwater area; because saturated soil conditions ivill kill grass. If (hese conditions are likely to occur, design options are given under "Design Criteria" (p: 6-39), or the wet biofilvation swate desi~ can be used (see Secfion 6.3.2, p. 6-49, for details). • Stormwater runoff cairying high concentrafions of oil and grease impairs the treahnent capability of a swale. Oil control options given in Section 6.6 (p. 6-12'n should be applied in these situarions. 15 Such modifications are often based on computer modeling using-fhe King Counry punoH Time Series (KCRTS) rtrodel. \60. Occasionalty they were based on bench-scaie studies. Back-up studies ere (sted in Reference Section 4. Surface Wa[er Desigu Manual August 1997 DcaR , SECIYON 6.3 BIOFII.TRAT[ON FACII,ITY DESIGNS , • Modifying an ezisdng drainage ditch to create an engineered biofiltration swale may be diffiwlt due to physical constraints and because ditches often serve as conveyance for flows from lazger offsite ~ areas. • Utilities may be located in swale side slopes above the WQ design depth. However, the repair or placement of utilities in swale side slopes iequires aggressive implementation of erosion control . practices to prevent soil from reaching the treatrnent azea of the swale. , Note: Consult the water quality menus in Section 6.1(p. 6-3) for information on how this facility can be used to meet Core Requirement # 8. AJso see Table 6.I.I.A on page 6-4 for guidanee on which rype of ~ . biofiltration swale(basic, wet or continuous inflow)to use for a given set of site characteristics. 6.3.1.1 METHODS OF ANALYSIS ' Biofiltration swale sizing is based on several variables, including the peak water quality design flow, longitudinal slope, vegetation height, bottom width, side slope, required 6ydraulic residence time (i.e., the time requi~ed for flow to travel t6e full length of the swale), and design flow depth. Swales sized and built using the method of analysis outlined in this section and the required design criteria presented in SecNon 6.3.1.2 aze expecfed to meet the Basic Water Quality menu goal of 80% TSS removal. Procedures for sizing swales are summarized below: ' Step 1: Calculate design dows. The swale design is based on the water quality design flow Q,;.y (see Section 6.2.1 (p. 6-IS) for a definition of water quality design flow). If a bioffiter is used for conveyance, the capacity requirements of Core Requirement #4 must be met. These flows musc be estimated using ihe hydrologic analysis procedures described in detail in Chapter 3. If the swale is located downstream of an , onsite detention facility; the swale design flow should correspond to 4he 2-year release rate from the deteution facility. ~ Step 2: Calculate swale bottom width. The swale bottom width is calculated based on Manning's equation for open-channel flow. T'his equation can be used to calculate dischazges as follows: ~ Q_ 1.49 o c~ o s -AR' s' n ~ where Q = flow rate (cfs) n = Manning's roughness coefficient (unidess) A= cross-sectional area of flow (s~ ~ R= hydraulic radius (fr) = azea divided by wetted perimeter s = longitudinal slope (fUfr) (6-1) ~ For shal}ow flow depths in swales, channel side slopes ar6 ignored in [he calculation of bottom width. Use the following equation (a simplified form of Manning's formula) to estitnate the swale bottom width: '- b _ Q„~~+,~q (6-Z) 1.49 ~ b~so.s Y' ~ where b= bottom width of swale (ft) Q,oy = water quality design flow (cfs) n,~y= Manning's roughness coefficient for shallow flow conditions = 0.20 (unitless) ~ y = design flow depth (fr) s= longitudina] slope (along direction of flow) (ft/ft) ~ See "Design Criteria" (p. 6-39) to determine the allowable design water depth. Proceed to Step 3 if the bottom width is caiculated to be between 2 and 10 feet. r Augus~ ~99~ Dratt (..76 Surface W atr,r Design Manual `'~,0 ~~"~"~"~ - b3:1 BA§ICBIOFII,TRATIQNSWALES-MEINODS-OFANALYS7S A minimum 2-foot bottom width is required. TherefQre, if the calculated bottom width is less than 2 feet, increase the width to 2 feet and recalculate the design flow depth y using Equation (6-3) as follows: 35 (6-3) y Qwq~q 1.49s°Sb where Q,,.q, n„~, and s are the same values as used in Equation (6-2), but b= 2 feet The maximum bottom width is 10 feet; ttierefore if ffie caiculated bottom width ezceeds 10 feet, then one of the following steps is necessary to reduce the design bottom width: • Increase the longitudinal slope s to a maeimum of 6 feet in 100 feet (0.06 feet per foot). • Increase Ihe design flow depth y to a ma~cimum of 4 inches (0333 feet). • Reduce the design flow rate by reananging the swale Iocation with respect ro detention facili6es; a swale located downstreazn of a detenGon faciliry may have a lowet flow tate due ro flow attenua[ion in the detention faeility. However, if a swale is located downstreatn of a detendon pond providing Level 2 or I.evel 3 flow control, and it is located in till soils (according to the KCRTS soil group in Chapter 3), [hen the swale must be designed as a wet biofil[ration swale (see Secdon 6.3.2, p. 6-49). • Place a divider lengthwise along the swale bottom (cross secdon) at IeasEthree-quarters of the swale length (beginning at the inlet), without compromising the design flow depth and swale lateral slope requiremen~See "Design Criteria" (p. 6-39) for swale divider requirements. A flow spreader must be provided at the inlet ro evenly divide flows into each half of the swale cross section. See Section 6.2.6 (p. 6-30) for details on flow spreaders. Step 3: Determine design flow velocity. To calculate the design flow velocity ttirough the swale, use the flow continuity equation: V,~.4 = Q,`.~ (~) ~ where V,,,y= design flow velocity (fps) A,,.y= by+Zy2= cross-sectional azea (5~ of flow at design depth Z= side slope length per unit 6eight (e.g., Z= 3 if side slopes are 3H:1~ ~ ~ ~ ~ ~ ~ If the design flow velocity ezceeds 1.0 foot per second, go back to Step 2 and modify one or more of the design pazameters (longitudinal slope, bottom width, or flow depth) to reduce the design flow velocity to . 1.0 foot per second or less. If the design flow velocity is calculated to be less than 1.0 foot per second, proceed.to. Step.4. Note: It is desirable,to have the design velociry as low as possible, both to. improve . treatment effectiveness and to reduce swale length requiremenfs. Step 4: Calculate swale length. Use the following equadon to detertnine the necessary swale leagth to achieve a hydraulic residence 6me of at least 9 minutes (540 seconds); L = 540V,„~ where L= minimum allowable swate length (ft) V,,,r= design flow velocity (fps) (6-5). The minimum swale length is 100 feer, therefore, if the swale length is calculated to be less than 100 feet, increase the length to a minimum of 100 feet, leaving the bottom width unchanged. If a lazger swale could be fitted on the site, consider using a greater length to increase the hydraulic residerice time and improve the swale's pollutant removal capability. If t6e calculated length is too long for the site, or if it would ~~~. Surface Wata Design Manual 6•37 Augus[ 1997 DraR ' SEC170N 63 BIOFILTRATION FACILITY DESIGNS ' cause layout probletns, such as encroachment into shaded areas; proceed to Step 5 to further modify the layout. If the swale lengt6 can be accommodated on the site, proceed to Step 6. Step 5: Adjust swale layout to 5t on site. If the swale leng[h calwlated in Step 4 is roo long-for the site, ' the length can be reduced by increasing the bottom width up to a mazimum of 16 feet. However, the length cannot be increased in order to reduce the botrom width because MaAning's depth-velocity-flow rate relationships would not be preserved. If Ihe bottom width is increased to greater than 10 feet, a low dividing bertn is needed to split the swale cross section in hal£ . Length can be adjusted by finding the top area of the 'swale and providing an equivalent top area with the adjusted dimensions. ' a) Calculate the swale treahnent top area based on the swale.length calculated in Step 4: AroP = (b~ + briop~ ) ~ (6-6) where A~oP = rop area (s~ at the desigu [rea[ment depth b; = bottom width (ft) calculated in Step 2 b,~~~ = the. additional top width ($) above the side slope for the design water depth (for 3:1 side slopes and a 4inch water depth, b,~~~ = 2 feet) L; _. initial length (ft) calculatbd in Step 4. ' b) Use the swale top area and a reduced swale length L~ to increase the bottom width, using the following equation: , Li ° Aroy (6_7) ~ ( 6~ +b,m~) ~ where I~ = reduced swale length (fr) bf = i~creased bottom width (fr). c) Recalculate V,,,q according to Step 3 using the revised eross-sectional azea A,,,q based on the increased i ~ bottom width br Revise t6e design as necessary if the design flow velocity exceeds 1.0 foot per second. Step 6: Provide conveyance capacity for flows higher than Q„q. BioFilVarion swales may be designed ~ as flow-through channels that convey flows higher than the waterquality design flow rate, or they may be designed to incorporate a high.flow bypass upstream of the swale inlet. A high-flow bypass usually results in a smailer swale size (see flow splitter options, page 6-26, for moie information on designing ~ bypasses). If a high-flow bypass is provided, this step is not needed. If no hi~Ylow bypass is provided, proceed with the procedure below: a) Check the swale sized using Steps 2 through 5 above to determine whether the swale can convey the ~ ~ 25-year and 10(},yeaz peak flows consistent with the conveyance requirements of Core Requirement #4 in Chapter 1. The roughness coefficient n in Manning's equation should be selected to reflect the deeper flow conditions with less resistance provided by grass during these high-flow events. The bottom width (Step 2) should be calculazed as per Section 4.4.1.2, "Methods of Analysis" for opea ~ channels. b) The ]00-yeaz peak flow velocity (V~~ = Q~~A~~) based on the 100-yeaz flow depth must be less than 5:0 feet per second. If V~~ exceeds 5.0 feet per second, retum to Step 2 and increase the bottom width ~ or flatten the longitudinal slope as necessary to reduce the 100-year peak flow velocity to 5.0 feet per second or less. If the longitudinal slope is flattened, the swale bottom width must be recalculated (Step 2) and meet all design criteria. ~ c) The conveyance requirements in Core Requirement #4 (see Secdon 1.2.4) must be met ~~y , ~ August 1997 Draft . . - Surface W ater Duign Manual . 6-38 63.1 BASICBIOFILTRATIONSWALES-DES/CNCR/TERlA 6.31.2 DESIGN CRITERIA An effective biofiltration swale achieves uniform sheet flow over and through a densely vegetated area for a period of several minutes. Figure 63.1 A(p. 6-46j shows a typical biofiltrauon swale schemazic. Basic design requirements for achieving proper flow conditions through a bio£ltration swale are described below. Swale Geometry 1. Swale bottom width shall be between 2 and 16 feeC - a) Minimum bottom width is 2 feet to allow for ease of mowing. b) If the bottom width exceeds 10 feet, a length-wise divider shall be provided. The divider shall extend from the flow spteader at the inlet for at least three-quarters of the swale length. c) Maximum bottom width is ]6 feet, excluding the width of ttie divider. Note: Multiple swales may be placed side by side provided theJlow to each swale is split at the inlet and spread separately for each swale. Adjacent swales may be separated with a venical wall, but a low berm is prefened for easier maintersance and 6etter landscape integration. 2. The lon~tudinal slope (along the direction of flow) shall be between 1 percent and 6 percent. a) If the longitudinal slope is tess ttSan I.5 percent, underdrains must be provided (see next page and Figure 6.3.1.C, p. 6-47, for underdrain specifications). . b) If the longitudinal slope is less than 1 percent, [he swale must be designed according to the criteria presented in Section 6.3.2 (p. 6-49) for wet 6iofiltration swales. c) If the longiwdinal slope exceeds 6 percent, check darns with vertical drops of 12 inches or less shall be provided [o achieve a bottom slope of 6 percent or less be[ween the drop sections. 3. The swale shall be flat in cross section (perpendiwlar to the Flow direction) to promote even flow across the whole width of the swale. 4. The minimum swale -ength shall be 100 feet; no maximum length is set. 5. The swale treatment area (below the WQ design water depth) shall be trapezoidal in cross-section. If trapezoidal, side slopes within the treatmenf area should be 3H: I V or flatter whenever possible, but not steeper than 2H:1 V. 6. Side slope sections above the treatment area may be steeper than 3H:1 V. a) If there is an iaterior side slope between 1H:1 V and 2H:1 V outside the treaunen[ area, the slope shall be reinforced with erosion control netting or matting during construction. b) Any interior slope steeper than 1H: ] V shall be constructed as a rockery or structural retaining wall'.e to prevent the swale slope from sloughing. To ensure that adequatfl sunlight ieaches the swale bottom, only one wall can be taller ihan 2 feet. 7. Curved swales are encouraged, but curves must be genUe to prevent erosion and allow for vehicle access ro remove sediment. Criteria for maintenance access road curves should also be applied for swate curves (see Sec6on 5.3.1.1 for design of access roads). ;; ~ 1~. Water Depth and Base Flow 1. A swale that will be Frequently mowed, as in commercial or la~dscaped areas, shall have a design water depth of no more than 2 inches (0.17 feet) under the water quality design flow conditions. 2. A swale that will not be frequently mowed, such as along roadsides or in iural areas, shall have a design water depth of no more than 4 inches (033 feet) under the water quality design flow condi6ans. ~13 1e Soil bioengineering techniques may be used ro-formdhe structural retaining wall. Jurface Water Design Manual . ... August~997 Draft SECI'ION 63 BIOFILTRAT[ON FACIL[T'Y DESIGNS t 3. If a swale is located downstream of a detention pond providing L.eve12 or I.eve13 flow control, and it is located in [ill soils (according [o the KCRTS soil group in Chapter 3), then the swale must be _ ' designed as a wet biofiltration swale (see Secfion 63.2, p. 6-49). 4. If a swale will receive base flows because of seeps and springs on site, then either a low-tlow drafn shall be provided or a wet biofiltration swate shall be used. C,ow Jlow drains aze narrow surface drains filled with pea gravel that mn lengthwise through the swale to bleed off base flows; they should not be ' confused with underdrains. In general, base flows less than 0.0] cfs per acre can be handled with a low-flow dtain. If flows aze likely to be in ezcess of this level, a wet biofiltration swale should be used. ' S. If a low-flow drain is used, it shall extend the entire length of ihe swale. The drain shall be a • minimum of 6 inches deep, and its width shall be no greater tBan 5 percent of the calculated swale botrom width; the width of the drain shall be in addi6on to the requ'ued bottom wid[h. If an anchored plate or concrete sump is used for flow spreading at the swale inlet, the plate or sump wall shall have a ' __ _ v-no[ch (ma~ci~m m top width = 5% of swale width) ot holes.[o allow preferential exit of low flows. . into the drun. See Figure 63.1.D, p. 6-48 for low-flow drain specificalions and details. '~ Flow Velocity, Energy Dissipation, and Flow Spreading 1. The ma~cimum flow velocity through the swale under the water quality design flow conditions shall ~ not exceed I A faot per second. 2. The m~imum flow velocity through the swale under the peak 100-year flow conditions shall not exceed 5.0 feet per second. '~ 3. A 17ow-spreader shall be used a[ the inlet of a swale to dissipate energy and evenly spread runoff as sheet flow over the swale bottom. Flow spreaders are recommended but not required at mid-length. For details on various types of flow spreaders, see Section 6.2.6. ~ 4. If check dams are used to reduce the longitudinal slope of the swale, a flow spreader shall be provided at the toe of each vertical drop. The spteader must span the width of [he swale. An energy dissipater should also be provided if flows existing the spreader could be erosive. ~ 5. If a swale discharges flows to a slope rather than to a piped system or confined channel, an energy dissipater shall be provided at the swale outlet. This requirement also applies to dischazges from swale underdrains. The outlet energy dissipater can be a rip rap pad sized according to the ~ specifications described in Table 4.2.2.F for conveyance system outfalls. Underdrains ~ If underdrains aze required per Item 2 under "Swale Geometry" (p. 6-49), they must mee[ the following criteria: 1. Underdrains must be made of PVC perforated pipe (SDR 35), laid parafleT to the swale bottom, and ~ backfilled and bedded as shown in Figure 6.31.C (p. 6-47). 2. For facilities to be maintained by tlie County, the underdrain pipe must be 6 inches or grea[er in diameter. (Siz inches is the smallest diameter pipe that can be cleaned withont damage to the pipe.) ~ 3. Siz inches of clean drain rock (5/e-inch minus) must be above the top of the pipe. 4. The drain rock must be wrapQed in geoteztile. Geotextile requirements aze summarized in Table ' 63.1.A (p. 6-41). S. The underdrain mus[ infiltrate into [he subsurface or drain freely to an acceptable dischazge point. ~ r ~ Augus[ 1997 DraR 6A0 Sudace Water Design Manual `-~a 6.3.1 BASICBIOFIL7RATTONSWALES-DESlGNCRIfER/A ~ ~~' ~~~ ~~+~4~6~'~s~s;~~ 0 ~ ~-~~ -~.x~.^s-~°,... "._ ` .r Geotextile Property ~€ ~ ` . ~~~~~-s~ ~.~ , ~. .~s~ ~:a~~~~ ~~r~a'~ = Value s: ~c. ~, - _ v , ., ~ ~ . Sn «`~~ ~s~._. Test Method Trapezoid tear (Ibs) 40 (min) ASTM D4533 Pertneability (cMsecj 0.2 (min) ASTM D4491 AOS (sieve size) #60 - 70 (min) ASTM D4751 Ulhaviolet resistance 70 percent or greater ASTM D4355 Note: Il constructlon crondi6ons dictate use of a more durable geotextile matenal to prevent'punctures or tearing dunng installafion, a heavier fabric should be used. Swale Divider I. IF a swale divider is used (such as when swale bottom widths are greater than 10 feet); the divider should be constructed of a firm material that will resist weathering and not erode, such as treated , lumber, concrete, plastic, or compacted soil seeded with grass. Selection of divider material should take into consideration swale maintenance, especially mowing. 2. The divider shall have a minimum height of oue inch higher than the design water depth. 3. Earthen berms should be no steeper fhan 2H:1 V. 4. Materials other than earth shall be embedded ro a depth su~cient to be stable. Access 1. For swales to be maintained by King County, an access road shall be provided to the swale inlet and along one side of the swale according to the schedule shown in Table 6.3.I.B below. Note: Counzy streets and paved parking areas adjacent to the top of slope may be counted as access. ~~'"~~e~~~ ~~ ~ 1 .~~~, ~ ~, -~~- ~-~ ~~.,k,.~.~ -t ..~ ~ ~v- H~..~~ L~S~L'.yf~1(~ ~ x~ : ~ x ~ ~.~ ~ : ~s ~r ~ :€°- ~, ~.. ~ s s ~~ ~ ~.. ~- I~T~'3'I1~~1~4'1~~~~~~ ~€l~~'£= ' „ f . , . ,, ~~~~.. ~-M~.~.~ ~ ~~: ~~~~ ~^~~ s. ~ ~~ ~~~ .-- Swale Area: L x w(s~. Access Road Length 200 - 1000 1/2 swale length L 1000 -1600 2/3 swale length L _ . Over 1600 _ . _ __ .__,. entlre.swale length L 2• In areas outside sensitive area buffers, wheel strips made of modular grid pavement may be built into the swale bottom for maintenance vehicle access instead of an access road. The. subgrade for the strips mdst be engineered to support a vehicle weight of 96,000 pounds and installed per the manufacturer's tecommendations on fum na6ve soil or structural fill, not on the amended topsoils. Each strip shall be 18 inches wide and spaced as shown in Figure 63.I.E (p. 6-48). The strip lattice should be filled or covered with native soil (no amendments required) and overseeded with grass. ff a low-flow drain is also needed (see "Water DeQth and Base F7ow" on page 6-39), a portion of the wheel strip may be filled with pex gravel as appropriate to fomi the drain. Wheel strips shall not be counted as Veatment area; therefote, the swale bottom width must be increased accordingly. `'~~ Surface Water Design Manuat August 1997 Draft L Al ' SECI70N 6.3 BTOFll.TRATION FACILITY DESIGNS ~^' Soil Amendment 1. Two inches (miniinum) of well-rotted compost s6all be tilled into t6e enqre swale treaunent azea to aznend the topsoil unless the soil already has an organic content of 10 percent or greater. This applies ' to both till soils as well as saudy soils. In very coazse soils (gravels or courser), top soil must be imported and amended to the required organic contenL a) Compost must be tilled into the underlying nauve soil to a depth of 6 inches to prevent the '. compost from being washed out and to ayoid creating a defined layer of different soil types that can prevent downward percolation of water. ,^ b) Compost shall not contain any sawdust, straw, green or under-composted organic matter, or toxic . or otherwise harmful materials. c) Compost should not contain unsterilized manure because it can leach fecal wliform bacteria into t^ receiving waters. J 2. Soil or sod with a clay content of greater than 10 percent should be avoided. If there is concem for` con[amination of the undedying groundwater, the swale bottom should be lined with a Veavnent liner ' to prevent groundwater contamination. See Section 6.2A (p. 6-20) for details on Veatment liner opdons. ' Planting Requirements 1. Grass shall be established throughout the entire Veatment area of the swale. ~ a) Seeding is best performed in spring (mid-March to June) or fall (late September to October). For , summer seeding, sprinkler systems or other measures for watering the grass seed must be provided. ~ b) Seed may be applied via hydroseeding or broadcast application. installation if seeding occurs in spring or er followin the first su d du ti i i i I ri g mm re on s requ r ng c) r ga summer. Swales seeded in the fall may not need irrigatioa However, maintenance and defect financia] guarantee will notbe released unless a healthy grass cover is established. Therefore, site , planning should address ihe need for sprinklers or other means of irrigaqon. 2. Swale Veatment areas are subject ro both dry and we[ conditions, as well as accumulation of sediment and debris. A mixture of dry-area and wet-azea grass species that can continue to grow through silt ' deposits is most effective. Two acceptable grass seed mixes for the King Counry area are listed in Table 63.1.C (p. 6-43). The mixes should be applied throughout the swale in the treatment azea at a rate of 80 pounds per acre. As an altemative to these mixes, a horticultural or erosion control '- specialist may develop aseed specificadon tailored to the site. Table 6.3.1.D (p. 6-43) lists grasses or other plants particulazly;olerant of wet conditions. Some of these seed types, however, inay not be commercially available. '- 3. A newly constructed swale shall be protected from stormwater flows until grass has been established. T6is may be done by diverting flows or by_covering the swale bottom with clear plastic untll the grass is well rooted. If these acdons are not feasible, an erosion control blanket shall be placed over the freshly applied seed m'vc. See detached Appendix D, ESC Standards, for details on erosion control ~ blankets. 4. Above the design treatment etevation, either a typical lawn seed mix or landscape plants may be used. However, for swales also used to convey high flows, consideration should be given ro the soil ' ' '. able d binding capacity of the vegetation. Acceptable grasses aad groundcovers are presented in 63.1.E (p: 6-44). Plant material other than that given in the table may be used if [he swale is privately maintained and the plants selected will not spread into the swale treatment area. Ivy may not be used ~~ because of its tendency to spread. Native plant species (e.g., kinnikinnick) aze preferred. "'' f g ty area. If these designs are used in other areas, Note: These recommendatioru are or the Kin Coun local knowledge should be used to tailor these recommendarions to Loca! condirions. 5od may be used as a temporary cover during the wet season, but sodded azeas must be reseeded with ~16 ~ a. suitable grass seed mix as soon as the weather is conducive to seed germination, unless the sod is ~ro ., from a seed miz suitable for the wetter conditions of a biofil7ation swale. Sod must be 8 .,k~tt ~ ~' ~ ~ Sucface Water Design Manual 6-42 - _- 63.1 BASIC BIOFII.7RATION SWALES - DESIGN CRITERIA iemoved or rotodlled into the underlying soIl before reseeding. Criteria #3 above for seeding should befollowed. ,. _ , ,-~ , - , E ~ - . s .. . ~ . . ... . . ... _... _~ . a. ~ . _~ _~.. Mix i . , , r . ,. _ _ , _ ., .~. i . r . . . r a .. . . _ .. _ . . . . + ~~ Mix 2 75-80 percent Tall or Meadow Fescue 60-70 percent Tall Fescue ~ 0-15 percent Seaside Crreping Bentgrass or Colonial Bentgrass 10-15 percent Seaside Crreping Bentgrass or Colonial Bentgrass 5-10 percent Redrop 10-15 percent Meadow Foxtail 6-1b percent Alsike Clover 1-5 percent Marshfield Big Trefoil 1-6 percent Redtop Note: All percentages are by weighL f ~ ~4 N"°S§ 'f~gck"~` Y"JS"~es `~ s ~°{v~, ~ . ._ ~~il~~SSY~~.G ~~~ ut i` ~I~~..a y~ ~ ~ , q~ 4. ~ ~ e r ~ :k.~AP~~~j~ ~~~~K t'z'fM~ r.~~ ~'-^ .~F+r'.RiY ~ '-~'.~ ~. :Y.FS~n... Grasses ay +.yf-~~~ 2 ] ~ ~FK" C.a~x' +.'t +f~4'~'~Y+~~f .~~t`~,~-L~~ 2 ~~~[[~.. } h ry F~ i'~"`f G'n_""R' ~~~'kt'.~..~~ ~ lf~k~~~ ~~ h' 3' a.~E.~~ ~ ~K ~. Wetland Plants Water Foxtail Alopecurus geniculatus Sawbeak Sedge Carex stipata Shortawn FoMail Alopecurus aequalis Spike Rush Eleocharis palusfis Bentgrass Agrosits spp. Slender Rush Juncus tenuis Spike Bentgrass A. exarata Redtop A. alba or gigantea Co~onial Bentgrass A. tenuis or capillaris Mannagrass Glyceria spp. Westem G. occidentalis - • ° ~ Northem G: borealis Slender-Spiked G.leptostachya . Rough-Stalked Bluegrass Poa trivialis Velvet Grass Holcus mollis ~~1 ~! ( SurfaceWaterDesignManuaj caa August 1997 Draft ~ r ~" SECIION 6.3 BIOFILTRATION FACII,ITy DESIGNS ~ ~ ' r~ r ~ ' r- r ~ l ~ ~ ~ r - ,a` , 4`~' ,~~.~~ _: _ ~5r.~,'`- ~ .- :~y"``~, ,.Y • ,.. ~. ' `m. ,i^:~ Grountlcovers ~ . . ~ ~ ~_ ~ ~ ~ E ~ ~ ~£^ ~~~'. Kinnikinnick' A~tostaphylos wa-ursl Epimedium Epimedium grandiflorum - Euonymus lanceolata Strawberry' Fragaria chiloensis - Genista St. John's-Wort Hypericum sempervirens Broadleaf Lupine" LupinuslaGfolius ` °' " White Sweet Clover' Melilotus alba Creeping Forget-Me-Not Omphalodes vema - Rubus calycinoides White Lawn Clover Trifolium repens Yellow-Root Xanthorhiza simplissima Grasses (drought-talerant, minimum mowing) 8uffalo Grass ~ Buchloe dacryloides Tufted Fescue Festuca amethystina Tall Fescue Grass' Festuca aiundinacea Hard Fescue " Festuca ovina dunuscula (e.g. , Reliant, Aurora) Red Fescue' Festuca rubra Dwarf Tall Fescues Festuca.spp. (e.g., Many Mustang, Silverado) Blue Oatgrass Helictofichon sempervirens ' Native species. Notes • Many other omamental grasses which require only annual mowing are suitable. • Ivy is not permifted because.of its tendency to spread. Recommended Design Features The following features should be incorporated into biofiltration swale designs where site condi6ons allow: r r ~ ~mgust 1997 DreR Swale Layout and Grading 1. If the longitudinal slope is less than 1.5 percent (requiring the use of underdraihs along the swale length), the subgrade should contain 10 percent or more of sand (o promote infiltration of standing water. If sand is added ro promote drainage, amendment of the soillsand substrate with compost is still required. 2. Underdrains are also recommended for swales greater than 1 S% longitudinal slope on 61] soils, especially if it is likely that ttie swale will intercept groundwater. 3. The alignment of a biofiltration swale should avoid sharp bends_where erosion of the swale side slope can occur. However; gradual meandering bends in the swale are desirable for aesthetic purposes and to promote slower flow. F AA Surface Water Design Manual ~ ` I I '~'''' li \ `~ , ~'~y~t~, I t ~~ 1 ~ 63.1 BASIC BIOFII.,TRATION SWALES -DESIGNCRJTERIA Location and Landscaping 1. During seeding, slow-release fertilizers may be apglied [o speed the growth of grass. If the swale is located in a sensidve lake watershed, low phosphorus fertilizers (such as formulations in the propoRion 3: 1: 3 N-P-K or less) or a slow-release phosphorus formulation such as rock phosphate or bone meal should be used. A typical fertilizer applicadon rate should be 2 pounds per 1,000 square feeL If az~imal manures aze used in the fertilizer, they must be sterilized to avoid leacbing fecal coliform bacteria into receiving waters. 2. Consultadon with a landscape or erosion control specialist is recommended for project-specific recommendations on grass seed, fertilizer, and mulching applications to ensure healthy grass growth. The grass mix should be capable of surviving and remaining healthy under both dry and wet conditions with limited maintenance. 3. A grassy swale should be incorporated into the sitelandscape design. Shrubs may be pianted along the edges of a swale (above the WQ treatment level) proyided that exposure.of the swale bottom to sunlight and maintenance accessibility aze not compromised. Note: For swales used to convey high flaws, the plant m6terial selected must bind the soil adequately to prevent erosion. 4. Swales should not be located in azeas whece trees will drop leaves or needles that can smother the grass or clog part of the swale flowpath. Likewise, landscaping plans should take into consideration the probiems that falling leaves and needles can cause for swale performance and maintenance. Landscape plante~ beds should be designed and located so that soi] does not erode from the beds and enter a nearby biofiltration swale. Construction Considerations 1. If a biofiltration swale is put into operation before all construction in the drainage azea of the swale is complete, the swale must be cleaned of sediment and reseeded prior to acceptance by the County. The Gounty will not release financial guarantees if swales are not restored and vigorous grass growth established. 2. I[ is preferable to provide good erosion control before runoff enters a biofiltration swale. Swales aze designed to handle only modest sediment loads from stabilized sites. Maintenance Considerations The design criteria given previously have incorporated maintenance concems into swale design. However, the designer should }a~ow the type and frequency of maintenance anticipated so that altemative proposals can incorporate maintecianee activity. Typical swale maintenance includes routine mowing, sediment and debris removal, and repair of eroded or scoured channel secdons. 1. Grass should be mowed to maintain an average grass height between 4 inches and 9 inches, depending on the site situarion. Monthly mowing is•needed from May through September to maintain grass r'`= <`"Vigor. If a swale is not mowed at least annually, trees and brush will invade the•swale and inhibit grass growth, compromising the swale's perfomiance for water quality treatrnent. ~ ~ ~ 2. Grass clippings should be removed from the swale and composted on site or disposed of properly off site. ~ ~ ~ 3. Sediment deposited at the head of the swale should be removed if grass growth is being inhibited for more than 10 percent of the swale length or if the sediment is blocking the even spreading or entry of water to the rest of the swale. Annual sedimentremoval and spot reseeding will probably be necessary. 4. If flow channelization or erosion has occurred, the swale should be regraded to produce a flat bottom width, then reseeded as necessary. If the channel results from constant base flow, it may be better to install a low-tlow drain rather than ro regrade. Regrading should not be required every year. 5. For swales with underdrains, vehicular access to the swale bottom (other than grass mowing 1q, equipment) should be avoided because the drainpipe cannot support vehicle weight. Considecation ` should be given to providing wheel strips in the swale bottom if access is needed. Surface Wa[er Design Manuai Augus[ 1997 DraR ' ~- SECTION 6.3 BIOFILTRATION FACILITY DESFGNS . ^ FIGURE 6.3.I.A BIOFILTRATION.SWALE SCHEMATIC ' ' ~ r flow t , r ~ flow r ~ (recon C biofiltration swa (min. swale Iengt r r r~ , NOTE: Longitudinal slope 1-6%. Provide underdrain for slopes < 1.5%. ^ ` , , r August 1997 Draft ~,. ..~ sintenance access road rodular grid pavement ~rous pavement, asphalt, ~ncrete or gravel) for hicle access roadway length depends.on >wale area (see text) Outlet Surface Water Design Manual l~ I ' __ _ '~I, - .6.31 BASICBIOf7L.TRA170NSWALES-DES/GNCR/TER/A ~ FIGURE 63:1.B BIOFII.TRATION SWALE CROSS-SECTIONS ' ~ '~I ~ , ~I l ~ , -.. '~. swale divider for width >10 ft water quality design depth (Y) = 4" max. _ ~ (2" for frequently mowed areas) Y+1"~ „~~t~~;~sv. L1L~L=~[.L~ bottom width = 2" compost tilied into 6" native soil max. = 16ft + divider min. = 2ft TYPICAL SWALE SECTION ~ NTS ' ~ ~ ~ FIGURE 6.31.C BIOFII.TRATION SWALE UNDERDRAIIV DETAII, Underdrain tor Slopes < 1.5% sl ` ~ soil amended with compost swale bottom ~ ;~ y~ %~~ ~ " SECTION ~ NTS ' ~. -fiiter fabric wrap of top, sides and bottom 6" min. amended soil 6' min. over pipe pertorated pipe underdraln centered beneath swale perforated underdrafn pipe centered beneath swale 5/8" minus clean drain rock DETAIL A filter fabr(c ~ NOTE: Underdrain must infiltrate or drain. freely to an acceptable discharge point. _ ~I ,~ ~ ~.~ -Sudace Water Design Manual ~ `~~ August 1997 Draft ' SECfION 6.3 BIOFILTRATION FACILITY DESIGNS ' FIGURE 6.3.1.D BIOFII.TRATION SWALE LOW-FLOW DRAIN ' conerete sump ' lon itudinal slo e 1-6q, notch or holes I co ~ A PLAN VIEW 6" min. deep pea gravel ~ NTS , trench length, of swale ~: -... (see text for application) ' ' ~ FIGURE 6.3.1.E BIOFII,TRATION SWALE WHEEL STRIPS r desi n bottom width b= ~ b1+b2+b3 i~~~~' , b1 18° b2 18" b3 ', ~ ,~:. ~ ~ „~ - = ~ - - ~ ~'S~ `~ compost amended soil ~~ . . .. . 6" O.C. ~ modutar grid pavers on native soil or engineered fill per manuf8cturer's recommendations r SECTION NTS top notch opening no more than 5% of swale botlom width or use ~ weep hoies 1 ~ `~° T ~ swale grade SECTION A NTS \b~' ~ August 1997 Draft - 6-48 our~ace vraiec ucs~gn mm~um ~ ' r ~ KING COUNTY, WASHINGTON. SURFACE WATER DESIGN MANUAL 6.6 OIL CONTROL FACILITY DESIGNS : This section presents the methods, criteria, and details for oIl conffol facilities that aze not discussed in other sec[ions. Included aze the following facility designs: , • Catch basin inserts, Section 6.6.1 • Oillwater sepuators, Section 6.6.2 Other oii control facilities include wetvaults, with ininor modifications (see Section 6.4.2, p. 6-75), and linear sand filters (Section 6.5.4, p. 6-119): Non-facility options include puking lot washing with proper disposa) of wash water and compliance with a NPDES permit that already addresses oil control. More information on non-strucNral options canbe found in the High-Use menu, Secrion 6.1.5 (p. 6-13). 'I~e information presented for each facility is organized into the following two cafegories: l. Methods of Analysis: Contains a step-by-step procedure for designing and sizing each facility. Information used in the procedure is based on available li[erature, but clarified or modified where deficiencies were idenrified.~ 2, Design Criteria: Contains the details, specifica6ons, and material requirements for each facility. 6.61 CATCH BASIN INSERTS A catch basin insen is a device installed undemeath a catch basin inlet that treats stormwater through , filtration, settling, absorpdon, adsorption, or a combination of these mechanisms. Catch basins vary greaUy in form, some being rectangular, tray-like swctures, some more like oil absorbant bags or pillows. Figure 6.61.A (p. 6-132) presenks a schematic representation of a catch basin insert. Ki~g County, in conjunction with other local agencies, has tested several catch basin inserts and found performance and removal rates to be highlybariable, depending upon system configuration, pollu[ant - particle size and concentration, an8 maintenance frequency. Because peiformance varies widely among the different devices, King County has developed a set of performance criteria that the devices must satisfy to be used for oil control pursuant to Special Reqtirement #5. Table 6.6.1.A (p. 6-128) lis[s the performance criteria and describes the tests to be used to eyaluate whether a device meets the criteria. Water Quality Treatment Objectives The catch basin inserts manufactured to date typically have been configured to remove sediment,. pollutants adsorbed to sediment, and oil and grease. The inserts described here are intended to capmre total peiroleum hydrocazbons ('I'PI~ for use in new or redeveloped high-use sites (see Chapter 1 for information on high-use sites). Devices meeting the design criteria outlined in Table 6.6.I.A (p. 6-128) should provide oil and grease removals comparable to those of other high-use treaVnent oppons. However, catch basin inserts provide litUe if any spill protection and do not meet spill-containment requirements unless the catch basin in which they aze installed has a tee section. While the inseRS described here aze focused on trea6ng TPH, catch basin inseres can also be configured with other sorbents to remove specific pollutants. Owners proposing ro use catch basin inserts to treat specific pollutants shodld obtain assistance from King County's business outreach program or from another pollution control agency such as the Depaztment of Ecology. Catch basin inserts also may be used for sediment control during construction, as described in Appendix D. In some instances, particulazly for redevelopment projecis "at high-use sites, existing catch basins may firs[be equipped wi[h inserts for sediment control during construction and then be reconfigured (e.g., changing treatmenf inedia) to trea[ TPH following completion of constiuction activities. ~$°~ ~ ~ Such modifica9ons were often based on computer modeling using the King County Runoff Time Series (KCRTS) model. Less ~' - .frequently ibey were based on bench-scale studies. Back-up studies are listed in Reterence Sectton 4. - Surface Water Design Manual August 1997 Draft . , ~.. ~ '^ . ' '^ ' ,^ , ' , , ~ ' r r r~ ~ r r r- SECITON 6.6 OIL CONTROL FACILITY DESIGNS .Y s ~ ..~Y~'~~~~ °~-~ 'y'~~ ~`~iL".3? ~~ 'F° ~~r'J 3 5 ~~-c~~: °rl&+. ~~ ~,f~ ~ 4e . ~Ey ~ ~~~~~ ~ ~t~z~~3"~ {.. ~ ~ S.- '~} ~F.'~'. ~~~~~. ~"~';.~. ~q y .. `a~ '~ ~ ~ ~ ~' ' ~ R ~,t'~„+2., ' ~ r . L ~ ~~~ ~~ 5f~Jtf~.il . ~~ .2~.~~'e~ l/ ~~ ~ ~ ~ ~ ~~~~` ~3E~ ~ ~ k. if- . ^~,i.s „~ ." ~~ T, ~FF, ~ ..., e 5'~ ~ 33 ~zerv. _ . _ s" . `~'~§.~t.G.l .fd'S~ ~ ~x 1 ~,.~ ~w€~ .. ~'t Criteria Methods of Eveluation 1 Insert has ability to treat the water quality Subject the system to the maximum flow rate when new, and design flow for a minimum of 6 weeks under again after 4 and 6 weeks deployment. All flow must pass typical high-tra~c conditions (in the Seattle through the treatment area without short-circuiting or area, this flow rate is approximately 19 gpm for. bypass. a drainage area of 5,000 square feet). 2 Insert has abiliry to create a positive seal Install and observe unit under low-flow conditions. Ali (low around grate to prevent low-flow bypass. must pass through the treatrnent area. 3 Media system functions so that its surtace does Inspect media after 4 and 6 weeks deployment. If filtration not become blinded shortly after deployment rate as tested in Method #1 above has been compromised and cause stortnwater to bypass media before and media still can absorb oil, clogging is a problem. full use of inedia is realized. 4 Medium resists water saturation and maintains Examine media after 4 and 6 weeks deployment for signs of oil-absorbing properties for a minimum of 6 water saturaHon or degradation. Media in acceptable weeks under constantly wet conditions. condition should still absorb oil and iepel water. 5 Insert has means of preventing floating oil from Inspect the insert for the presence of an under-over weir at escaping the unR. This requirement will be the high-flow relief. If this or some comparable device waived for inserts designed to be used with a exists, it is assumed that free oils will be retained. tee section or down-turned eibow. 6 Insert has means of preventing oil-soaked When the insert is new, and again after 4 to 6 weeks media from escaping the unit. deployment, subject it to the peak fiow rafe (defined under Criterion #7) and observe whether media escapes. 7 Insert has ability to pass high flows without Blirid all filtration surfaces with plastic sheeting and subject causing excessive ponding; no ponding to the insert to the required flow. No ponding around the drain occurforthe 25-yearpeakflow rate (in Seattle inletshould occurforthe 25-yearpeakrate. this rate is approximately 43 gpm for a drainage area of 5,000 square feet). 8 Manufacturer provides complete installation Verity that instructions include information on the following: and maintenance instructions. . InstallaUon . • Creating an adequate seal • Removal (including safety consiiierations) • Cleaning and replacement • Decant and disposal of liquid wastes . . . Media disposal guidance Desirable Features Methods of Evaluation 7 Insert has 15igh-flow bypass to prevent Subject the insert to the flow rate calculated for Criterion #1, resuspension and washout. and then gradually increase the flow: Only the designed flow rate should pass through ihe treatment surfaces. 2 Service contract is provided. There is no method for evaluating service contracts. Service contracts are listed as a desirable feature because they may offer greater assurance of regular system maintenance and, consequentfy, treatment reliability. Note: The evaluation tests assume the usa of suita6le oil-absorbing/adsorbing media (see hlaterial Requirements,° p. 6-130). August 1997 DraR 6-128 Surface Water Design Manual `$~ 6.6,1 CATCH BASIN INSERTS Applications and Limitations Consult the water qualiry menus in Section 6.1 (p. 6-3) for Enformation on how catch basin inserts can be used to meet Special Require~ent #S. Note that catch basin inserts may not be used to satisfy Special Requirement #5 if they would be installed in a publieroad right-of-way which would be maintained by King County. This is because the County does not have the resources needed to maintain catch basin inserts as frequently as needed for effecrive operaHon. Catch basin inserts may be used to meet the oil control requirements for new or redevelopme~t high-use si[es. The minimal space requirements, planning and engineering needs, and implemen[ation [ime make catch basin inserts particulazly attractive for redevelopment projects. The initial cost investment may be much lower than that of comparabie oil treatrnent options. However, long-term costs associated with the more frequent maintenance required for catch basin inserts may offset some of the inifial cost savings. Applicanis considering catch basin inserts aze encouraged to investigate maintenance costs associated with a particulu device. Costs for maintaining catch basin inserts aze on the order of $10 to $100 per unit per month, assuming monthly media replacement. The use of a catch basin insert may be limited by drainage area, available space inside the cafch basin, availability of maintenance personnel or services, and access. Catch Basin Interior Space Pipe stub-outs, misaligned inlet frames, and shallow drainage systetns limit the use of catch basin inseds for redevelopment. Therefore, an applicant considering catch basin inserts for a redevelopment project inust ensure that the devices are physically compaGble with existing catch basins and will achieve the desired performance. Availability of Maintenance Staff or Services To be effective, a catch basin insert must 6e maintained at a frequency recommended by the manufacturer, but at least monthly (the cycle may be extended up to six weeks depending upon local conditions; see "Maintenance Consideradons" on p. 6-131). Because of the importance of regulaz maintenance, owners using catch basin inserfs will be required to keep a maintenance log that specifies when the facilities were cleaned or replaced; the log must be availahle for rediew by County inspectors. Commercial maintenaiice services for facilities like catch basin inserts aze increasingly available. Applicants intending to use catch basin inserts should include maintenance in a rou[ine program such as grounds maintenance or contcact with a commercial service. Applicants planning to use. a catch basin insert should also consider the weight of candida~e devices and whether the insert must be completely lifted out of the catch basin to be maintained. Some of the inserts currently produced are heary and may require two people or machinery, such as a forklift, to perform routine maintenance. 6.6.1.1 METHODS OF ANALYSIS Catch basin inserts require.li[tle design or analysis but must meet the design criteria listed in the following section: _ , . 6.6.1.2 DESIGN CRITERIA Figure 6.6.1.A (p. 6-132) illusVates the general configuration of a catch basin insert. Catch basin inserts must meet the criteria ouHined below. Unless otherwise stated, use of a catch 6asin with an insert must also meet the requirements bf Chapter 7 of the King Counry Road Standards (e.g., ca[ch basin spacing, unpiped runoff distances, etc.) unless the project is a redevelopment project and the drainage ne[work is already established. Catch basin inserts may not be used to satisfy Special Requirement #5 if they will be installed in a public road righbof-way and maintained by King County; another option from tf~e High-Use menu must be used instead. / igj~ Surface Water Design Manual ~ ~ ~ August 1997 Draft 6-129 SECI70N 6.6 OIL CONTROL FACILTI'Y DESIGNS r General 1. The total maximum tributary azea for catch basin inserts should not ezceed 5,000 squaze per unit for new developmeut projects. This limit is based on a target of treating 90 percent of the runoff volume. ~ For a 5,000 squaze foot impervious azea in the Seattle region; this flow is approximately 19 gallons per minute (gpm), or 0.04 cubic feet per second for the WQ design flow.40 The tofal inaximum h-ibutary area shall not exceed 7,000 square feet per unit for redevelopment projects. . ~ 2. If a manufacturer develops a catch basin inseR that is provea to effectivel'y treat flow rates higher than 20 gpm (0.045 cubic feet per second) without releasing previously trapped material (in accordance with Performance CYiteria #1, #5; and #6 listed in Table 6.6.1.A, p. 6-128), King County may allow specific catch basin inserts to drain areas lazger than 5,000 square feet. 3. A catch basin insert for a new development project shall be designed to 5t witli a standard grate, as specified in the King County Road Staridards (see KCRS Nos. 41 and 42). If t6e insert is installed in ~ an ezisdng catch basin, the insert shall be demonsirated to fit properly so that there is a positive seai azound the grate to prevent low-flow bypass. The maximum heiglit of tt~e grate above the top of the frame, with the insert installed, shall not exceed 3/16 inch, and the grate should be non-rceking. ~ 4. Catch basin inserts shall be accessible as needed for maintenauce and not limited by continuous vehicle parking. This may require eliminating a pazking stall for redevelopment projects. ~ Material Requirements 1. A catch basin insert mustbe fi[ted wi[h oil-absorbenUadsorbent filter media, to be changed at least monthly (October to June) and whenever t6e filter media surface is covered with sediment. ~ Acceptable sorbent media include wood fiber products such as Absorbent W or SuperSor6, whole fibrous moss (need not be sphagnum), or Peirolok; these media have been investigated by the County and found to retain capmred oil fairly effectively. StreamguardTM ~polymer (cuirently distributed by Foss Environmental) was also tested using [he same method established by the County a~d found to ~ achieve acceptable oil retention. Other products which absorb oil without significant release are also acceptabie." Other polypropylene-based products aze expected to be acceptable, although none but the StreamguardT"~ polymer fiave been investigatedto date. ~ 2. Unacceptable filter media. Cedaz Grove compost was tested and found unacceptable For oil retention. Compost from CFS Treatment Systems, Inc., who produce a patented leaf compost, was also tested. Although it performed fairly well, i[ did not retain oil as well as [he other products [ested. Therefore, ~ CFS leaf compost should not be used in catch basin inserts for oil control. Other materials that are unsuitable for use in catch basin inserts include Fuller's or diatomaceous earth and kitty litter. 3. To minimize the generation of solid waste and the consumption of natural resources, systems ~ constructed of or using recycled products are preferred. Reusable filter materials should be refres6ed according to [he manufacturer's instructions. ~ Recommended Design Features While no pretreatment is required with a catch basin insert, the use of the source control BMPs described in the King County Stormwater Polluaon Control Manual (available from DNR).will decrease ~ maintenance needs. Catch basin inserts may not be used in place of source control best management practices. ~ Construction Considerations 1. Installation of a catch basin insert for a new or redevelopment project shall follow the manufacturer's recommended procedures. The insert should be installed in the catch basin afrer the site has been ; i 40 Testing~ by King County indicates that few oi the devices tested could continue 1o meet Veahnent requirements at 9ow rates in I ~ ~ excess o( about 20 gpm. In addition, due to the very short contact time end potential for flushing prevfously trepped matarials, ~- treatrnent wouid be compromised at higher flow rales. ' 41 Criteria used tor acceptable absorbent malerials are that a complelely ofl-satureted sample oi the material dces rrot release 1 ~ ' _ more tban 10 mylL of total petroleum hydmcarbon in any two minule period when flushed with tap water (running at a rate oi ~ 0.3 to 0.5 gpm) tor 70 consecutive minutes. . ~• i August ]997 Draft - Surface Water Design Manuat ~`k- 6-130 '' ~~, - - _ - ~ . . . . 6.61 CATCH BASIN INSERTS ~' ~ paved or stabilized (for ~ew d'evelopment) or after completion of conswction (for a redevelopment site that is already paved). 2. If a catch basin insert is used for sediment control during conswcdon, it should be reconfigured in accordance with the manufacturer's recommendaeons. When used for sedimenE control, the insert should be inspected at least weekly and maintained if needed (see Appendix D for information on using the inse;t for sediment control). Maintenance Considerations 1. Catch basin insert systems require more frequent maintenance than ot6er oil treatrnent systems. While maintenance requirements of individual units may be relatively minor, the need for diligence and the potentially lazge number of units required in place of other more typical oil treatment systems make sound maintenance planning essential to the successful use of these devices. 2. A declazation of covenant allowing the County to inspect facilities and maintenance records shall be recorded for the project site per Core Requirement #6 (see Appendiz lOD for wording). 3. Maintenance needs vary from site to site based on. the type of9and use activity, implementation of source controls, and weather conditions. Catch basin inserts should be maintained at a frequency recommended by fhe manufactarer, but at least monthly during the wet season (October Uuough June) and once every 2 months during ihe remainder of the yeaz: Note: During the first wet searon, it is recommended that inspection be canied out every other week to determine whether a shorter maintenance cycle is needed for the panicular site. 4. Main[enance shall include full replacement or renewal of oil absorbenUadsorbent materiaL In addition, when maintaining the insert, the catch basin sump should be inspected for sediment accumulation. Sediment should be removed if the depth of sediment in the sump is greater than 0.5 feet_ An inspection and maintenance log shall be kept onsite and made availabte to County inspectors on an as- needed basis. At a minimum, the maintenance ]og shall inciude the following information: date, type of maintenance performed, names of persons performing the work, and signature: Persons conducting maintenance activities should weaz rubber gloves for health and safety pro[ec[ion while handling used filter media. 5. The opeiation a[id maintena~ce instructions from the catch basin insert manufacturer shall be kept with the maintenance log. Manufacturer's instructions should i~clude installation, removal (including safety instructions), cleaning a~d replacement (including a practical means of detemvning when the unit is in need of service), and media disposal guidance (including decanting of licjuid wastes). 6. Owners should follow_ the manufacturer's inswctions for dewatering filter media, which vary depending on the type of unit. Generally, catch basin inserts that drain by gravity can be dewatered in place during dry weather. If an owner is unable to perform monthly maintenance because there has not been sufficient dry weather, the maintenance period may be extended up to an additional two weeks: If by the end of the additional two weeks there has been insufficient-dry weather to allow dewatering, the owner shall make other arrangements for dewatering the filter media. Such anangements could include use of a commercial seryice, dewatering the insert in a watertight container, or other me[hods meeting environmental iegiila6ons. Me3ia sNall be disposed of in accordance with applicable ' regulations, including the Seatde-King County Depaztment of Public Health solid waste regulations (~tle 10) and State dangerous waste regulations (WAC 173-303). In most cases, dewatered filter media may be disposed of as solid waste. ,~~ Surface WaterDesign Manual August 1997 Draft 6.131 ' SEGITON 6.6 OII, CONTROL FACILITY DESIGNS ' FIGURE 6.6.1.A SCFIEMATIC OF CATCFI BASIN INSERT '^ Tributary area <_ 5000 s.f. . ~700~ S.f. If f8~ovolnnmcnt project replac ~ surface). ' t^ ~ . 1 , 1 1 t r r - r SECTION VIEW NTS r r r r r ~ Augusi 1997 Draft - ~ - ~ . 6-132 .~~~w >sorbent material lia) (see text) a housing ri of outlet pipe outllow ~ Surface Water Design Manual ~ ~ ; ~ ~~ , ~ ..._,__. ;.H:~ . ~ --. '~ ,~ ,~ ' '~ ~~ ~_ KWG COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL KING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE REQUII2EMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES . Section No. Subiect 1 Detention Ponds 2 Infiltration 3 Closed Detention Systems 4 Control Structure/ Flow Restrictor 5 Catch Basins 6 Debris Barriers 7 Energy Dissipaters 8 Fencing 9 Gates 10 Conveyance Systems 11 Grounds 12 . Access Roadsl Easements 13 Water ~uality Facilities A) Biofiltration Swale B) Filterstrips C) Wetponds D) Wetvaults E) Sand Filters . F) Leaf Compost Filters G) Infiltration Ponds , 14 Oil Control Facilities A) Oil/ Water Separators B) Catch Basin Inserts `~~ Surfaca Water Design Manual August 1997 Draft ~~ ' 1 ~ ' ,~ ~ '~ .,~ ~~: ,~ ~ ~ 1~ 1 ' +' '1 'l ~ 'L ~ , ~ i ,Y r APPENDIX A MAINTENANCE S.TANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL N0.1 - DETENTION PONDS Maintenance Defed Conditions When Maintenance Results Expected When - Component ~ ~ - - Is Needed ~ Maintenance I5 PeAormed ~ General ~ Trash & Debris ~ Any trash and debris which exceed 1 cubic toot Trash and debris cleared from site. - ~ ~ per 1,000 square feet (this is about equal fo the - ~ - ~ amount of irash ii would take to fill up one standard size o~ce garbage can). In general, there should be no visual evidence of dumping. ~ ~ Poisonous Vegeta6on Any poisonous or nuisance vegetadon which No danger of poisonous vegahetion . ~. may constitute ahazard to County personnei or where County personnei or ihe the public. ~ public might normaliy be. ~ ~ (Coordination witti Seattle-King ~ ~ CounTy Health Departrnent) PofluNon - Oil, gasoline, or other contaminants of one No confaminants present other ihan ~ - gallon or more or any amount found that could: a sudace film. (Coordination with~ ~ 1) cause damage to piant, animal, or marine life; Seattle/King County Health ~ . 2) constitute a fire hazard; or 3) be flushed Departrnent) . downstream during rain storms. ~ ~ Unmowed Grass/ It facility is Iocated in private residential area, When mowing is needed, ~ ~ Ground Cover mowing is needed when grass exceeds 18 grass/ground cover should be inches in height. In ofher areas, the general mowed to 2 inches in height. . - policy is to.make the pond site match adjacent Mowing of selected higher usa ~ ground cover and terzain as Iong as there is no areas ralher ihan ihe entlre slope interference with the tunction ot the facility. may be acceptable for some ~ ~ - situations. ~ Rodent.Holes Any evidence of rodent holes.if taciliry is acting Rodents destroyed and dam or , as a dam or berm, or any evidence of water berm~repaired. (Coordination wfth piping tlirough darn or bertn via rodent holes. SeattleMing County Health , . ~ ~ Departrneot) ~ Insects YJhen insects such as wasps and homeLS Insects deshoyed or removed.from _ ~ , fntertere~with~maintenanceactlviUes.. site. ~ . ~ Tree Growlh Tree gmwth does not allow maintenance axess Trees do not hindar malntenance - _ or interferes with maintenance activity (I.e., siope activitles. Selectivety cultivate trees -- - mowing, silt removzl, vactoring, or equipment such as alders for firewood. ~ movements). It trees are not fntedering with aceess, leave trees alona. ~ . Side Slopes.of.Pnnd: -..: Emsian Storage Area Sedimant Eroded damage over 2 inches deep where cause of darnage is stiil present or where there _ . , is potenttal (or continued erosion. Accumulated sediment that ezceeds 10 % of tha designed pond depth. Slopes should~be stabilized by ~ using.appropriafe erosion conVOl~ measure(s); e.g., rock reintorcement, planting of grass, compaction. Sediment cleaned out to designed pond shape and depth;~pond ~ reseeded if necessary to conVOl erosion. Pond Dikes ~ Setllements Any part of dike which has settled 4 inches lower Dike shouid be~bult back to the ~ . - than the design eievation, design elevation. . Emergency Rock Missing ~ Only one layer of rock exists above natlve soil in Aep~ace rocks to design standards. Overflow/Spiliwey area fiue square teet or larger, or any exposure of naNve soii at the top of out flow path df ~ spillway. Rip-rap on inside slopes need not be~ ~ ~ ~ repiaced. . . ~qo Sudace Water Design Manual A-1 August1997 Draft~ '^ APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELYMAINTAINED DRAINAGE FACILITIES ~ NO: 4- CONTROL STRUCTURFJFLOW RESTRICTOR Maintenance Defeet ~ CondiUon When Malntenance is Needed Results Expected When - CompoAent ~ ~ . . ~ ~ Maintenance Is Pertormed ~ l - General. - Trash~ em1 Debris Distance belween debris build•up and bottorti of All Vash and debris removed. . ~.(Includes SedimeM) orifice plale is less than 1-12 feet- ~ - - ~ . . Structural. Damage Structure ts notsecurety attached to manhole wall Structura securety ettacbed M~ ~ and outlet pipe sVucture should support at least wall end outlet pipe. ~ . _ i,0001bs of up or down pressure.- ~ ~ Shucture Is rrot in upright position (ailow up to SWCWre in correct position. ~ . . 10% from plumb).- . " ~ , Connections to outlet pipe ere not watertigh! end Connectlons to outlet pipe are ~ ,.~ ~ show signs of rust ~ , - water tighC, structure repaired or ~ iepleced and works as .,. .~._ . .. ,..,~.. :,, ...,: .. , ~.. designed. . . ~ ~ Any holes-other than designed holes-in Ne StrucNre has no holes other _ ~ siructure. ' - than designed holes. ~ ~ Cleanout Gate ~- Damaged or Missing Cleanout gate is not watedigbt or fs missing. . Gate Is watertight and works as ~ ~ ~ - ~ designad ~ Gate cannot be moved up end down by one Gate moves up and down easily . maintenance person. and is watertight. Chain leading to gate is missing or darnaged. Chain is in place and works as ' ~ . _ designed. ~ Gate is rusted over 50% of its suAace area. Gate is repelred or replaced to ~ ~ - meet des(gn standerds.. r Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place~artd works as _ missing, out of place, or bent oriflce piate. designed._ . ~ - - ~ Obstructions My hash, detiris, sediment, or vegetation Plate is free of eli obstrucfions ~ . blocking the plate. -~~ end works as designed. ~ Overtlow Pipe Obstructions Any trash or debds blocking (or having the. ~ Pipe is free of all obstructions potentlal of blocking) Ne overflow plpe. ~ and works as designed. Manhde -. ~ ~ ~ See'Gosed Deten6on Systems' Stendards No. 3 See'Closed Detention System5 - ~ Standards No. 3 Catch Basin ~ . See'Catch Basins' Standards No. 5~ See'Cfltch Basins' Standards . ' No. 5 ~ r r r r August 1997 Draft A-0 Surface Water Design Manual - ~a~ AEpENDIX A MAINTENANCE BTANDARDS FOR PRIV ATELY MAINfAINED DRAINAGE FACII.IT'~S ~ NO: 5 - CATCH BASINS Malntananca ~ Defect .~ Conditions~ When Ma(ntenance is Needed ~ Component' General Tresh & Debris = Trash or dabris of more than 7/2 cubiC toot which is ~ (Includas Sedimeni) located tmmediateiy in front oi the catch basin . opening or fs blocking capacity of the basin by . more lhan 70% . Trash or debris (in the b~sin) that~exceeds 1/3 the No trash or debris in the catch depth Irom the boriom ot bazin to invert tha lowest basin. pipe into or Qut of the basin. - Trash or debris in any fnlet or outlet pipe blocking ~ more than 1/3 of its beight ~ Dead animals or vegetatlon that could generate odors that couid cause complaints or dangarous gases (e.g., methane)• ~ . DeposiLS of garbage exceeding 1 cubic foot in - ~ vdume .. ~ ~ SVUCture Damage to ~ Comer ot irame extends mora than 3/4 inch past Frame:and/or Top Slab curb tace inlo the streef (If applicable). ~ Top slab has holes larger ihan 2 square inches or Top siab is free of holes antl cracks wider than 1!4 inch (intent is to make sure . cracks.- . all material is running into bazin). ~ ~ _ ~ r ~ r f ~ ( ~ ~ r' r , 1~ Frame not sitting 9ush on top slab, i.e., separation Frame is sitting Flush on top of more than 314 inch of the irarne from ihe top slab. - slab. Cracks In 8asfn Walls/ Cracks wfder than 1/2 Inch and longer Than 3 teet, Basin ieplaced or repaired to - Bottom - ~ any evidence ot soil partlcles entering caich basin - design standarcls. ~ ' ~ thiougfi cracks, or maintenance persori ~udges that - . ~ sirucNre is unsound. ~ . ~ ~ - - ~ - Cracks wWer than 12 inch and longer ihan 1~Toot No cracks more then 1/4~ inch - - -~-~ -~-- - ~ -~~ •--~ ~~ - ~ ~--•- , - ~ - - ~-~ at the Jofnt of any InIeU outlat pipe or any evidence- . ~ wide at ihe.jant ot inleUoutlat of soil partides entering catch basfn through ~- . pipe. ~ ~ ~ .. ~ crecks. . . - . . ~ _ . SedimenU ~ Basin has~ settled more than 1~Inch or has rotated Misalfgnment . more than 2 inches ou[ oi aGgmnent Results Eupacted When Mafntenance-IS peRormed No Trash or debris located immediatety (n front of catch basin opening. Inlet and outiet pipes free of . trash or debris. No d`ead animals or vegetation present within the catch basin. No condilion present which would attrad or support the breeding o~ insects or rodents. Frame is even with curb. Basin replaced or repatred to design standards. ~qv Sudace Water Design Manual e_c Avgust 1997 Draft ' . APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAWED DRAWAGE FAC7LITTE5 ~ , NO. 5 - CATCH BASINS (CONT/NUEDj - ~ Malntenence~ Defect CondRions Wheh~Maintenaneels Needed Resulfs Expected When ~ , Component . ~ ~ Malntansnee is pedormed . Fire Hazard ~- Presance of chemicals such as natural gas, dl and -~ - No flarnmable chamicals gasoltne. . . present . ~ VegetaUon ~ Vegetatlai growing acrags and blocking more than No vegetation blocldng opening 10% ot the basin opening. . ~ to basin. Vegetatlon growing in InieVoutlet pipe jolnts that is No vegetaHOn or root growth - ~ trwre than six.inches tall and less than six inches ~ presant. ~ _ ~ apart. t Poilution - . Nonflammable chemtcals o1 rtwre than 12 cubic (oot per three teel of basin length. ~ .- , - ~ . No polludon pregent oNer than surface film. ~ ~ ., ;:..:;. . .._ . .,...: . . . , ~ Catch Basin Cover Cover Not in Place ,:~...- . : _. ~ Cover fs missing or onty partially fn place. My opan - ~. - _. . .. .. . ._ . . Catch basin cover is closed - ~ ~ ~ catch basin re,yuires mafntenance. . ~ ~ ~ . ' Locking Mechanism . ' Mechanism cannot ba openad by on maintenanca . . Mechanism opens wiTh pmper ~ Not Working ~ person with proper tools, Bolts into frame have less . tools. " . ~ ~ ~ ihan 7l2 ineb of ihread. ~ ' . ~ Cover Difficutt to ~ One mafntenance person cannot remove Ifd efter ~ Cover can be removed by one Aemove appiying 801bs. ot Ilft; intent is keep cover trom . . malntenance person. ~ - ~ sealing ott access to maintenance. ~ _ _ ' Ladder ~ Ledder Rungs Ladder is unsafe due to missing rungs, misalfgnment,. Ladder meats design stendards - Unsafe rust, cracks, or sharp edges. . and allows maintenance person ~ MeTal Grates ~ ' - Grate with opening wider than 7!e inch. ~ sate access. Grata opening meets tleslgn ~ ~ (If Applicable) ~ ~ standarcls. , Trash and Debris ~ Trash end de6ris ihat is blocking rtwre than 20% ot . . Grate free of trash and deb~fs. ~ ~ ~ grete sudace. - . - ~ ~ ~ ~ ~ ~ Damaged or ~ ~ Grate missing or broken tnember(s) ot ihe grate. Grate is in place and meets Missing. - design standards. - ~ - - I NO 6 D S . EBRI BARRIER S (E.G.; TRASH RACKS) ~Meintenance ~ Defect . C . Conditlon When Malntenance fs Needed ~ ~Aesulb Expected Wben ~ omponents ~ ~ ~ - -Malntenan~e ls Performed.~ - General Trash end Debns Trash or debds that is plugging more then 20%ot Bartier clear to~ receWe capacity ~ ihe openings in the bariiec tlow. ~ Mefal ~ Damaged/ Missing ~ Bars are bent out ot shape more than 31ncAes. ~ Bars In place witl~ no bends rtwre - Bars. ~ . thad3/4 inch. . ~ ~ . . ~ Bars are missing or entire barrier missing. ~ - Bars tn place according to design. 8ars ara loose end rust is causing 50% deterloration , Repalr or replace barrier to ~. . ~ to any part of bartier. - design standards. .. . r ~- «,3 ~ August 1997 Draft A-6 surrace wata nu;gn trtanual. ' APPENDIX A MtlIN7ENANCE STANDARDS FOR PRNATELY MAINTAINED DRAINAGE FACILI'TIES , N0.12 - ACCESS ROADS/ EASEMEMfTS Maintenance Defect - - Conditlon When Malntenance la Needed Results Expeeted When ~ Component - Malntanance is Performed~ peneral Trash and Debris Trash and debris exceeds t cubic foot per 1,000 Roadway free ot debris whfch ~ . ~ square feet f.e., trash and debris xrould fill up , could damage tires~. ~ ~ ~ . . . . ' Btodced Roadway one standards size.garbage can. . . . Debris which could damage vebide tfres (glass - ~ - - Roadway free of debris which ~ ~ ~ or metal). . ~ - - could dama9a tires. . ~ ~ - My obstruation which reduces clearence above ~ Roadway ovarhead clear to 14 teet . ' road suriace to less than 14 feet high. ~ ~- - My obsWCtlon fg'StricUR~ 1Hfi aceess ta a 10 to Obshuction ramoved to allow at - 12 foot wgltn fbf ~ ilistence of more tban 12 feet leazt a 12 foot flceess. ~ or any poifi~ f45fficfin~ AdCess to less than a 10 foot width. ~ Road SuAace Settlement, Potholas, _ Mush Spots, Ruts When any surface detect exceeds 6 inches in - depM and 6 sq~are feet in area. In general, anY Road surtace uNformly smooth with no evidence ot sattlement, sudace~defect which hinders-or prevents poMoles, mush spots, or ruGS: -- " . maintenanceaccess. ~ . ~ - . - ~ - . Vegetation in Road Weeds growing In ihe road surtace Wat are Road surface free of weeds taller ~ SuAace more than 6 inches tall end less than 6 inches than~2 inches. tall and less than 6. inches apart witt~in a 400- ~ - . ~ square toot area. - ~ ~Shoulders aqd Erosion Damage Erosion within 1 foot of ihe roadway more lhan 8 Shoulder tree of erosion and Ditchas inches wide and 6 incties deep. matching the sunounding road. ~' ~ Weeds and Brush - Weeds and brush exceed 18 inches in heigM or hinder maintenanca access. Weeds and brush cut ro 2 inches in helght or cleared in such a way as to allow maintenance access. l N0.13- WATER QUALITY FACILITIES A.) Biofiltration Swale Maintenenee Defect ~ Condition When Maintenanee Is Needed Resutts Expeeted When . ~ Component ~ ~ Maintenanoe is Pertormed Biofiltration . Sediment Accumulation . Sediment depth exceeds 2-inches No sedmant deposits on grass on Grass Layer . ~ .. . laqer of tbe bio-swale, which would ~ ~ ~ ~ . . . -~, impede filtradon of YunoH. Vegetadon ~ When ihe grass becomes excessively tall Vegefation is mowed or nuisance (greater then 14fnches); when nuisance weeds yegmtadon is eradicated, such that ~ and ott~er vegetatlon starts ro take ovec . ~ 9ow rrot impeded. Grass should be ~ mowed to a~ beight between 4 Inches end 9~inches. ~ ~ ~ Inlet Outlet Pipe InIeV ouUet pipe clogged with sediment and! or de6ris. No dogging or blockege in the Inlet end oWet piping. Trash and Debris Trash and debris accumulated in ttie bio-swale. Trash and debris.removed from Accumulation - ~ ~ bioswale.- ~ ~ Erosior/ Scouring W here the bio-swale has eroded w scoured Biosvrale should be re-graded and - . . the bolrom due to flow channelization, or higher re-seeded to spedfication, to ~ Flows. eliminated channetad tlow. - , ~ .~ Overseeded when bare spots are ~ evident r ~ i;,:,* c. ~q~c August 1997 Draft A-10 SurFace Water Daign Manual APPENDIX A MAINTENANCE STANDARDS FOR PRNATELY MAINTAINED DRAIIVAGH FACII.ITIES N0.13- WATER QUALfTY FACILfIIES (CONTINUEi~ B.) Grasslined Fitter Strips Maintenance . Defect -. ~ Condition When Maintenance is Needad Results Expectetl When . Component, _ . - . _ ~ Mafntenance Is PeAormed - Fllter SMp Sediment Accumulahon Sediment depth exceeds-2 ~nChes. ~ No sediment dapasits on grass on Grass Layer ~ - . , tayer ot llie filter strip, whfch would , impede fiiVatlon runoff: ~ Vegete8on When the grass becomes excessively tali ~ (greatar tlian 10-inches); when nuisanca weeds . and other vegetatlon starts to take over. Trash and Debris Trash and deb~s accumuiffied on~the filter Accumulatlon ,. . : strip. - Erosion/ Scouring Where the filter sMp has eroded or scoured - ~ due to flow channelization, or higher Flows. Vegetadon is mowed or nuisance vegetatlon is eradicated, such ihat flow nvt impeded: Carass should be mowed to a height behveen 4 inches and 9 inches. Trash and Debris remwed from filter. Strip should be re-graded and re- seeded speciflp8on, to eltminate - channeled flow. Overseeded when bare spots are evident ~ ~ V-NOich Pipe Weir When the V-Notch pipe becomes darnaged or Cteaned and properly functioning ~ ~ clogged with sediment[ debris. . weir, such that Flows uniformly • . ~ " spread. ~ ~ C.) Wetponds Malntenanee Defect Condition When Maintenance Is Needed Results F~cpected When Component - ~ . ~ Maintenance Is Pertormed Wetpond ~~ Vegeta6on Vegeta6on~ such as grass arM weeds need to be Vegetation should ba mowed to ~ - mowed when il starts to impede aesthetics of pond. 4 to 5 inches in height. Trees ~ Mowing is genera0y requiied when height exceeds and busbes should be~removed 18-inches. Mowed vegeta8on should be removed where they are interfedng wifh ~ trom areas where it couid enter ihe pond, either - pond maintenance activities. ~ . , - wM1en the pond Ievel rises, or by rainfall runoH. ~ - - .. Trash and Debris Accumulation that exceeds 1 CF per 1000-SF of ~ - Tresh and debris removed from ~ pond area. ~ pond. ~ ~ InIeV OWet Pipe Inietl Outlet pipe clogged with sediment anN or ~ No dogging or blockage fn the . dabds material. _ Inlet and outlet p(ping. ~ . Sediment ~ ' Sedtment accumulations in pond bottom tliat ~~ Remaval of s~ment from pond - Accumulatlon in Pond exceeds the depth of sedment zone plus 6-inches, bottom. ~ - Bottom ~ ~ usually the flrst cell. ~ - . . ~ Oil Sheen on Water Prevalentand.yisible oil sheen. ~ Removal of sediment trom pond . .. .. ~ . ... bottom.. Erosion Erosion of the~pond's side Slopes and/ or scouring of Slopes should~be stabillzed by - the pond bottom, thal ezceeds 6-inches, or wbere using proper erosion contml '. . - ~ . continued erosfon is prevalent ~ . ~ measures, and repaft methods. - . SettlemeM of Pond ~ Arry part of these comPonents ihat has setlled 4- Dike/ berm is repaired to . . Dike/ Berm ~ inches or lower than fhe destgn elevation, or specificatlons. .. inspector detertrrines dike! berm is unsound. ~ . -~ . , Rock Window Rock window. ts clogged wi(h sediment - - Window is free of sediment and - - ~ ~ ~ ~ ~ debris. Overilow Spillway Rock is missing and soil is exposedat top of - Replace rocks to specifications. ~ spillway or outside slope. . ~~J Sudace Water Design Manual . , August 1997 DcaR A•11 I APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILTI'fES '~ N0.14 - OIL CONTROC FACILITIES (CONTINUED~. _ A.) Oil/ Water Separators (Continued). ~ Maintenance Defect Conditlon When Malntenance Is Needed Resulte Expected When ~ ~ Component . . : ~ . - ~ . - Malntenenee Is Pertormed ~ ~ Darnaged Coalescing Plate media broken, detormed, cradced and~or - Replace that portion ot media ~. . Plates . showing signs offailure. . pack orentire plate peck . ~ ~ ~ ~ . . . . depending on sevedry of fallure. ., . Damaged Pipas Inlet or oWet piping damaged or broken and in need . Pipe repaired and or repleced. ~ of repair. ~ ~ ~ ~ ~ ' Baffles . _ Baffles covoding, cracking, warping arid/ or showing Repair or repleca betfles to - signs nf failure as determined by maintenance! spedfirations. _ inspection person. . ~ ~ ~ ~ Vault Structure - ~ Cracks wider than 1!2•inch and eny evidence of soiF . Vault replaced or repafred to ~ Demage• Includes - partlcles entering the sWCture tfirough ihe cracks, design specifications: °~-~ ,_ Cracks in Walls,. or maintenance tnspection personnel determines . Boriom, Darnage to Nat the vault is not stmcturally sound. ~ ' ~ - Frame andl or Top ~ ' Slab - ~ . ~ ~. ~ Access Ladder Ladder Is conoded or delerioreted, not fimctioning Ladder replaced or repaired and ~- . Damaged propedy,-missing rongs, cracks, and misaligned, meets~spedficadons, and Is - - sate ro use as detertnined by - ~ ~inspectionpersonnel. ~ ~ ~ Cracks wider than 1/2-inch at tbe joint of any inleV ~ No cracks more than i/4-inch outlet pipe~ or any evidence ot soil particles entering wide at the Joint ot ihe inlef/ ~ the vault ihrough the walis. outlet pipe. _. ' B.) Catch Basin Inserts Melntenance ~ Component Defect Conditions When Maintenance is Needed - _ . Aesuits Expected When Malntenenee Is Performed Catch Besin Sediment " When sediment forms a cap over the insert media ot No sediment cap on the fnsert Accumulation ' the insert and/ or unit. media end IPs uniL Trash and Debris Tresh and debris accumulatas on insert unit creating Trash and debris removed from ~ Accumuialion a 6lockage! restridion. - insert unit. RunoN ireety Oows ~ . ~ Into catch basin. . Inspeclion Inspection oi medie insert is required. Effluent~water from media insert ~ is free ot als and has no WsIWe - sheen. . Media lnsed-Water ~ Catch basin Insert is saturated with water, whicF~ no Rertwve and replace media ~ Saturated longer has ihe capacity to absorb. insert . ~~ Media lnsert-Oil Media oil saturated due to petroleum spfll thet drains Remove and replace media Saturated into catch basin. inse2 - ~ r~ General Regular interval replacement due to lypical everage - ~Remove and replace media~at . ~ lite of inedia insert product regular intervals, depending on ~ ~ ~ irisert product. r . r r ~q6 ~ August ]997 DraR ~ . . . ' ~Sudace Water Design Mannal ~ A-20 ' ' APPENDIX D EROSION AND SEDIlVIENT CONTROLSTANDARDS ~ ~ K1NG COUNTY; WA,SHINGTON SURFACE WATER DESIGN MANUAL King County Depariment of Natural Resources Department of Development and Environmental Services August 1997 . c~~r~ \a~ I ' - KING COI1N'I'Y, SURFACE WATIIZ DESIGN MANUAL , D.4.3.3 VEGETATED STRIP ' 1N~ Code: VS Symbol: -~- ' Purpose To reduce the transport of coarse sediment from a construction site by providing a temporary physical ~ barrier to sediment and reducing the runoff velocities of overland flow. Conditions of Use 1. Downslope of all distuibed areas. '. 2. Vegetated strips are not intended to treat concentrated flows, nor are they intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the _ drainage system to a sediment trap or pond. The only circumstances in which overland flow can ~ be treated solely by a strip, rather than by a sediment trap or pond, is where the area draining to the strip is small (see introduction to this section) and the average slope is not more than 1.5H:1 V. i_ Design and Installation Specitications 1. The vegetated strip shall consist of a 25-foot wide continuous strip ot dense vegetation with a permeable topsoil. Grass-covered, landscaped areas are generally not adequate because the volume of sediment oyerwhelms the grass. Ideally, vegetated strips shall consist of undisturbed native growth with a welt-developed soil that allows for infiltration of runoff. 2. The slope within the striP shall not exceed 4H:1 V. 3: The uphill boundary of the vegetated strip shail be delineated with clearing limits as.specified in Section D.4.1 ~ ~ Maintenance Standards 1. Any areas damaged by erosion or construction activity shall be seeded immediatety and protected by mulch. 2. If more than 10 feet of the buffer width has had vegetation removed,.sod must be installed: 3. If there are indications that concentrated flows are traveling across the buffer, surface water controls must be installed to reduce the flows entering the 6uffer, or additional perimeter protection must be installed. ~~~ Sudace Water Design Manual ~ ~ D-17 ~ August 199'7 Proposed ' ' ' 1 , t ' ~ ~ r ~ r ~ Technical Note #30 from Waters6ed Protection Techniques. 7(3): 117-119 ~ Performance and Condition of Biofilters in the Pacific Northwest hat exaclly is a biofilter? Some would say Local govemments in the Puget Sound region of W ashington have huned to biofilters as wst-elFective ~ methods to treat urban stormwater runofl: T6ey aze passive, technically simple, and flexible methods of treating runoff in ~developing areas. Biofiltntiw is a process where stormwater is treated by contact with vegetation and soil sudaces along a long and broad grass swale. A cooperative team of reseazchers from several cities and aniversities has investigated the performance of biofilters over t6e ]ast few years. In addition, the researchers have gathered field data ro define some ofthe most critical variables for the design ofbiofilters. ~ it ts a gassed swale with class. More technically, it a swale [ha[ is explicitly desi~edto treat stom~waterrather [hanjust conveying it along. In the last few years, our Imowledge about biofilters has increased as a result of reseazch from the Pacific NoRhwest. The biofilter design process relies on an adaptation of Manning's fovnula of open channel flow for t6e su month, 24-hourdesign storm, using an iterativeprocess ~ con strained by a specified ma~timum veI o ciry and sl ope. Manning's formula for open channel flow expresses. the relationship amoag all of the principal biofilter desi~ variables, with the exception ofbiofiltet length. I[ is frequently e~cpressed as follows: Q=~(1.49/n) 3 A~ Ro.n a Sos where Q= tLe volvmehic flow rate, ft'/s n= Manning's coefficieni, accounting for boundary friction ~ A = cross-sec[ional azea, fl' R= hydraulic radius, tl~e ntio of cross- sectional area to wetted perimeter, ft s = channelslope(Rvertical/fthorizontal) Homer et al. (1988) have developed an iterative biofilter design procedure based on the capacity of the biofilter during t5e water quality design event and the stability (erosion potential) ofthebiofilter during more exheme events. Key design variables in Homer's pro- ce&ne include [he Manning's n value, swale shape, ma~cimum flow velocity for [he design storm, and resi- dence time in the biofilter (Seattle Metro,1992). To determine the pollutant removalperfom~ance of a typical biofilter, tl~e City ofMow~BakeTerrace (Wash- ington) constructed a test 200-foot long biofilter. T6e geomehy of the trapezoidal biofilter was as follows: 4%average slope, five-foo[bottom width, and 3i I(h:v) sideslopes. Average residence tune for Iunoff within the biofilter was computed tobe justunderten minutes. The biofilter was about two yeazs old, and was mowed [wice a year. The biofilter served a compara[ively large 15.5 acre wa[ershed, consis[ing of single family and multi-family residential homes, parks, and a major arterialroad.Totalimperviousnessinthecontriburing watershed was appro~cimately 47%. Duringthesecondphaseofthestudy,theupper100 fee[ ofthe tes[ biofilter was piped, [hereby effectively reducing its leugth by half. This modification enabled the researchers to test the perfmmance of biofilters designed for a shorter length and coiresponding resi- dence times (about five minvtes). Runoff iuflow and outflow from the 200-foot con- figuration wasmonitored during su storm events in the sum»ierand fall of 1991.Anadditionalsix flow-weighted composite samples were collected from tLe shorter 100.footbiofilterintheFalland Winterof I992. Removal rates were computed based.on the ehange in poltutant concenhation occnaing between tLe inflow and ouU flow from the biofilter. ConsequenNy, the sampling method did no[ measure the possible reduction in pollutant loads due to runoff infiltration within the biofilter itself. Intiltration, however, was very minor. The swale was on a glacial till notfazbelowthe surface, and the upper soil layer was observed to sahuate rapidly (<1 hour) after the onset of a stoim. ~ The 200 foot long biofil[er was found ro be reason- ~ ably effective in removing many pollutants contained in urban stormwater (Table 1). In general, high rates of removal were reported for sediment, hydrocarbons, and particulate trace metals, but nutrient removal was very modest Less than 30% of the total phosphorus entering the biofilter was removed, and the biofilter actually was a net exporter of nitrate. More encourag- ingremoval rates were observed forbiological(y avail- ablephosphorusfomis. Siuprisingly, thebiofiltertended to increase the level offecaLcoliformbacteria as runoff passed through i[. This inaease was thought to be due to pet droppings and possible bacterial multiplication , withintfiebiofilteritself. - ~~, ~q~, ~ r ~- r ~~ Pollutant . Suspended Sediment ~~ Turbidity ~ TPH (Hydrocarbons) Total Zinc Dissoived Zinc ~ Total Lead . . Total Aluminum ~ Totai Copper TotaIFPFiosphorus - ~ ~ Bioavailable P ~ ~ ~ Niirate-N Bacteria 100foot 200foot ~biofilter(°/) bio£Iter(°/>) 60 83 60 65 49 75 16 63 negative 30 15 67 16 63 2 46 45 . 29 72 40 negative negative negative negative , Asmightbeexpected,the100-footlongbiofilterdid not pedorm as well the longer version, although cleaz statistical dif}~erenws were only noted for two pollu[- ants. Removal rates for We shorter biofilter were also more inconsistent (higher standard deviation). The one exceprion to this pattem was the moderate to high removal observed for various forms of phosphorus. This result, however, may be a sampling artifact, as the j greaterremoval rates occuaed during storms thatpro- ~'~. duced very low phosphorus concentrations at the in- ' flowpoint . ~ Based on the monitoriag study, the reseazch team concluded that a five [o ] 0 minute residence~ time in a minimutrt 100-foot long biofilter would ensurereliable pollutaut removal, particularly for storms with signifi- cant rainfall peaks. The project site also allowed the researchers to compute detailedmeasurements ofactual Manning's n values under typical biofilter conditions. Three ind~ peudent methods were used to measure velocity of flow, and a range of n values were compufed for the biofilter(from 0.192 to 0.198, when ithadbeen mowed to a Leigh[ of su inches). Generally, the value of n did not vary with small changes in slope, but did vary with flow rate. The reseazch team recommended a standard Mannir~g's n value of at least 0.20 for stotmwater biofilter design. Unmowed, tailer grasses were com- puted to have higher Manning's n values during bigh~ flow-events (approximately 0.24). . One of the frequeutly cited concem s ab out biofilters involves howwell they aze constructed and maintained in the field Homer and his colleagues (1958) surveyed the condition of 44 biofilters in the field. The study - ~ ~ Characteristics Percentof biofilterssampled Vegetativetype Natural grass - ~ ~--27 Grass seed mix .41 Emergent wetlands 30 ~ Vegetativecover ~ _ Full 59 Some bare spots 30 Poor 11 Dry weather flow Dry 36 Standing water 38 Running water 17 InletType ~ Curb cut 18 Culvert pipe 63 Unchannelled 18 Soil infiltralion rate high 18 200 feet or longer 66 Slope less than 2% ~ 86 Had check dams 6 Sideslopes Gentie 30 Steep 70 Had been regutarly mowed 41 Had been maintained 50 ~Cross-sectional shape Trapezoidal 33 Parabolic 50 indicated that there clearly was plenty of room to improve inboth areas (Table2). Forexample, about four in 70 biofilters did not have the dease grass cover necessary to achieve effective filtration. Similazly, only 40%ofall biofilters were dryduringthe siunmermonths- the remainder had standing or running water. A high proportion of [he biofilters could be referred [o as "biocanyons," as they.had sideslopes in excess of 3:1 (h:v). Neaziy all the biofilters that received runofffrom c~b cuts had significant sed'unent deposi[ion at the edge of the biofilter that could impede the~entry of nmoffinto the system. Most si~ificantly, less than half ~ ' ~ ofallbiofiltershadeverbeenmaintainedaftertheywere constructed. Periodic grass mowing was the mainte- ~ nanceacfivitypedonnedmostoftea(41%). Based on both the monitoring and field experience, . the research team has suggested refined design cri[eria to improve the perfonnance of biofilters, which aze ~ summarized in Table 3. The biofilter does appeaz to be a promising technique to treat the quality of urban ~ srormwa[er, but will reqtire future improvements in design, maintenance and landscaping One particulaz designimprovementwo.uldbetoplacemorebiofilters ~ off-line.In this even[, they would only treat runofffrom ~ thewaterqualitydesignstorm,butwouldbypasslarger ~ stoim events that produce geater mnoff depths, aze more erosive and could possibly mobilize pollutants trapped in biofilter soils. ~ , ^ Geometry ~ Preferted geometry minimizes sharp cor- ners and has gentle slopes, parabolic or ~ trapezoidal shapes, with sideslopes no ~ grealer than 3:1 (h:v) ~ ^ Longitudinal slope Should be in the range of2 to~4%. Checkdams should be inslalled if slopes ~ exceed 4°/a and underdrains installed if slopes are less than 2°/a. ' ^ Swale width Should be limiled to no more than 8 feet, unless structural measures are used to ensure unifortn spread of Flow. ~ ^ Maximum residence time ~ Try to achieve a hydraulic residence time for the 6 month24 hour storm of about 9 ~ ~ or 10 minutes. - ~ ~ ^ Maximum runoff velocity No more than 0.9 fps for 6 month, 24 hour stortn, and no more than 1.5 fps for 2 year ~ - ~ storm event. ^ Mannings n value Recommend the use of a 0.20 vaiue in ~ design ^ Mowing Routine mowing is used to keep grass in ~ active growlh phase, and to maintain ~ dense cover. ^ Grassheight Normal grass height should be at teast ~ two inches above design tlow depth. ~References Homer, R. et al. 1985. BrofrltraNan SystemsjorStorm RunoffWaterQualityCon[rol. WashingtonDept. ofEcology.84pp. " Seattle MeVO and Washing[on Ecology. 1992: Biofilhation Swale Perjormance: Recommenda- tions, and Design Considera6ons. PubGcation No. 657. Washington Dept of Ecology. 220 pp: ^ Biofi/ter Soils A sandy loam topsoil layer, with an organic matter content of 10 to 20°~, and no more than 20% clay. If soil test indicates that the current soil does not meet these criteria, a surface layer topsoil amendmenl may be used. ^ Water table - Designer should check to detertnine the level of the seaso~ally high water table. If it is within a foot~of the bottom of the ~ biofilter, it may be advisable to select wetland species. ^ Plant sefection Seled grass species that produces a - unitortn cover of fine-haidy vegetalion that can withstand the prevailing moisture condi6on. Wetland adapted species such as Juncus and SGrpus may be utilized if drainage Is pooc " ^ Landscaping ~ Other plant material pn be integrated into a biofitter, but care should be taken to prevent shading or leaffall info swale. ^ Construction ~ Use of manure mulching or high fertilizer hydroseeding~to establish ground cover should be avoided during construction, as these can result in nutrient export. ~` ~~ , ' ' ~ ~ , ' ' ~ r- ~ ~ r r r ~ L~ ~ Technica! Note #96 from Watershed Protection Techniques: 2(4): 511-524 Performance of Dry and Wet Biofil#ers Investigated in Seattle iofilters are grass channels desi~ed to treat stortnwater runoff instead of inerely convey- ing it downstream. To remove pollutants, biofilters employ greater swale lengths, broadbottoms, gentle slopes, and dense grass huf. Together, these factors increase theresidence time ofmnoffthroughout the channel, allowing [ime for adsorption, uptake, set- tling and filtering and infiltration ofs[otmwaterpollut- ants. A monitoring study by Seattle METRO indicaYed that a 200-foo[ longbiofiltershowed promise in remov- ing many pollutants fouud in urban stormwater. Biofilters aze easy to design and construct and are extremely cost-effective in comparison to other piac- tices. For these reasons, [he wncept is gaining popu- lariry in the Northwest although the practice is not yet commonplace. Asmorebiofilteis azebeing cons Wcted, some nagging questions remain. First, t6e pollutant remQVa] capability ofbiofilters is derived from a single monitoring study. Ifmore biofilters aremonitored, will they confimt thepollutan[removal capabi]ity of[he firs[ study or show it to be a sampliug fluke? Second, field inspections have consistently shown t6a[ mos[ biofilters arc noi consW cted and maintained under the ideal test conditions that were followed iu the first monitoring study. Doespollutantremova] pedovnance decline in biofil[ersthat are in Fairorpoorcondition, and " by how much? - Two recent studies from the grea[er Seattle area explorethese questions in some detail.In the fuststudy, Jennifer Goldberg inves[igated the performance of a bio£Iterretrofitknown as the "Dayton Aveaue Swale." The origiual channel was a 600-foot long drainage ditch located in theright-of-way separating the backyards of a residential area: It was converied into a biofil[er by reshaping t6e dimensions of the channel, adding top soil over the glacial till soils, and re-planting a dense coverofgrass. The new dimensions ofthebiofilterwere a length of 570 feet, a base width of five fee[ and an average Iongitudinat slope of ]%. Figure I sLows a cross-section of the new and broader chaunel, with other site aud design data provided in Table I, . Goldberg sampled eight storm events at Dayton swaleduring 1991 to 1993. Samplecollectionwaslimited by "lost flows" (i.e., ana]ysis of the biofilter revealed that as much as 30 [0 80% of all incoming runof3~ infiltrated ioto [6e soil and never reached the down- stream end). Goldberg noted that downstream runoff was seldom observed unless t6e biofil[er soils were already saturated, and the rainstorm had at least mod- erate intensity and long duration. In addition, incoming sed'unent often dropped ou[ in the fust 50 feet of the biofilter, forming a small "hump° tf~at impeded the flow of stormwater and caused minor ponding. In general, the investigators found it difficult to main[ain a con- stant grade aloug t6e entire length of the biofilter. Investigators also discovered possible intemal sovrces ofpollution within the biofilter,.including a colony of mountain beavers [hat made tLeir burrows in the side slopes, pets that ioutinely used the biofilter [o defecate, and adjacent trees that dropped rottiag fruit inro the ~ swale. /~~ IS - A bio~lte~ has much broader and longer dimensions than a typical grass channel. ' ' ~ ' ' r r ~ '' , ~ ~~ r r r r ~ r r 16 Design charecteristic Drainage area ~ Length Slope Base width - Crosssection shape Vegetative condition Design criteria for two year 24 hourstorm event Maintenance Application No. of Storms Sampied Pollutant removal method ~ Dayton Avenue 90 acres, 20% Imperv 570feet 1 °h 5 feet Parabolic Full grass cover Maximum Velocity: 1.5ff/sec Max Runoff Depth: 9 inches Manning's 'n' : 0.07 Mowed se4eral times/year, clippings removed Retrofit of conveyance channel ~. 8 events ~ Change in upstream downstream. concentration Swale 17 acres 350feet 1.1°k 6.8 feet Trapezoidal Dense wetland cover, with some subchannels fortned Conveyance only Never mowed, trees growing on lower side-siopes New development 17 events Flow weighled change in wncentration Despite these lunitations, performance monitoring revealed that the Day[on biofilterwas reasonably effec- tive (Table 2). Suspended sedimen[ concentrations were reduced by 68°/a, atid turbidity dropped by a smalleramoun[(41%). W6ileremovalofto[alphospha rus was uegligble (5%), thebiofilterwas able toremove 30to 35%ofsoluble orbiologically-availablephospho- rus. in contrastto othermoni[ored biofilters, the Dayton swale showed a modest capability to remove nitrate (31 %). The biofilter reduced concentrations of fotal aluminum, copper and leadby 40 to 60%, but was only able to reduce soluble copper levels by 20%. Concen- trations of oiUgrease in the biofilter's outflow were ~ always below detection limi[s.1'he biofilter, however, did a very poor job in reducing fecal coliform bacteria. Bacterial concentrafions fromtheDaytonbiofilterwere about three times higher in the ovtflow than the inflow, ~ which is not surprising given the poten[ial intemal bacterial sources observed (e.g. pets aud beaver). Over- all, the perfortnance ofthe Dayton Avenuebiofilterwas generaliy compazable to that of the original MonHake Terrace biofilter site. Removal rntes for bo[h sites may be conservative since pollutants enhained in [he "lost flow" [hrough the biofiltet could not be accounted for in thepollutantremova( calwlations. While losing flow to infilhation makes monitoring a challenge, in£ltration can be a majorpollutant removal pathway forbiofiltets and indicates the practice is functioning property. TheUplandSwale The second study conducted in Kings County iuvolved a swale that could be termed an "accidenta( biofilter." Althovgli the Uplands Swale was originally designed as a conveyance channel, it was constructed tbdimensionstha[wereverysimilar[o abiofilter.Its350. foo[ long channel had trapezoidal shape, a base width of 6.8 feet, aud a longitudinal slape of 1%(see Table ] . for more site and design data). 7Le channel had been excavated to neaz or below the water table, and conse- quently, the swale had standing water and dense wet- land vegetarion. Clumps of soft rush (Juncus e/jusus) dominatedthewedandplantcommunity,al[houghsome. ~ dense stands of cattail (Typha Jatifolia) were also present Flow tended to chauneliu around [he cli~mps of soft msh, but spread more imiformly as it passed [hrough cattail stands. ~ Althoughinfiltrationclearlywasnotafactorinthis wet swale, it did appeaz ro store some runofffrom minor stoims (less t6an 0.3 inches ofrainfall) and, as a cons~ quence, runoff was seldom measured a[ the swale outflow during minor storms. Like many biofilters, the Uplands Swale had been neglectedpriorto monitoring. Poor past construction practices deposited perhaps as ~ much as a foot ofsedimenton tUefloorofthe swale.?.nd even though the upper slopes of the biofilter were mowed about once a year, a dense growth of young alders aud willows had become fully es[ablished along the lower side-slopes, and were starting [o shade the channel. '^ ~ W ' ' ' , r ' , r ~ r r-+~ I~, ~ r r r I ~ ' '~. TheUplandsSwalewasselectedformonitoringfor ~ asimplereason itwascharacteristicofmanybiofilters actually installed in the field--soggy, poorly main- tained, and with we[land plants replacing grass cover. As part of the study, King County staff also inspected the field condition of32 other biofilters. Field inspeo- tions found only 27% of biofilters in good condition with tmiform gass coverandno channelization, with an additiona140%ofbiofilters reporied to be in faircoudi- tion (some bare patches, minor channelization and ~ soggyconditionsunpairingpedormance).Theremain- ing 33%ofbiofilters were classi£ed as "poor" and were presumed to have little, if any, pollutant removal capa- bility (i.e., vegetation was absent and channelization was conspicuous). Major factors cited forpoorbiofilter - condition were, in rnnk order, poor initial vegetative es[ablishment, soil saturation or ponding, , channelization,shadingbyoverhangingtreesandsedi- ment deposition from construction activity. All of these faciors were prescnt to some extent at the Uplands Swa]e. Because prior monitoring had in- volved biofilters operatingunderrela[ively ideal condi- tions (Dayton and Mondake Terrace), the King County smdy focused on biofilters in fair condition. Seventeen storm events were sampled in the Uplands Swale from 1994 to 1995. Pollutant removal was calculated on the basis of upstream and downstream changes in flow- weighted event mean concentrations (EMCs). Asmightbe expected, the pollutantremoval perfor- mance of this wet swale was mixed (Table 3). On the positive side, the Uplands Swale reduced suspended sed'unen[ conceatrations by 67%, which is comparable to the perfonnance of a bioft][er in good condition (i.e., Dayfon). Reduction in total phosphorus concentra- tions through the wet swale was also notable (39%). On the other hand, the wet swale [ended to inaease the coaceatra[ion of soluble and biologically active phos- phorus, indicating that the swale's soils or vegetation was releasing these phosphorus forms. The grea[est release occurred during the non-growing season, whereas removal was often positive in the late spring and early smnmerwhenwetlandp]antgrowth wasmost vigorous. A similaz phosphotus removat pattem was observed in an earlier study of a Florida wet swale. A miuor reduction in nitrate (9%) and ammonia (16%)was noted inthe wet swale, whichmayhavebeen due to plant uptake or microbial action. Monitoring genemilyindicatedihatmetal concentrationswerelazgely unaffected during their transit t7uough the swale, al- though detection limit problems and quality control complicated the analysis. Little change was noted for total lead (6%) and total zinc (-3%), and a net release of total copper was computed. The effect of the wet swale on dissotved metals was even more equivocal, with vutuallyno concenhation changerecorded during most storm events, and more importantly, very little change with respect to aquatic toxicity thresholds. Pollutant Removal Rate ~ Inflow Conc. Suspended Sediment 67.8 Turbidity 44.1 Total Phosphorus ~ 4.5 Soluble Reactive Phosphorus 35.3 Bio-active Phosphorus 31.9 Nitrete-Nitrogen 31.4 Total Lead 62.1 Total Copper 41.7 Dissolved Copper 20.9 Fecal Coliform Bacteria -264 OillGrease not detected Removal Rate Pollutant (%) Suspended Sediment 67 TotalPhosphorus 39 Sol.-Reactive Phosphorus (-05) - Bio-active Phosphorus (-31) Nitrate-Nitrogen 9 Ammonia-Nitrogen 16 Total Copper (35) TotalLead 6 Total Zinc (-3) Although the pol(utant removal capability of [he Dayton Avenue and Uplands swales weie.no[ as great as other stormwaterpractices, they do appearto play an unportant role in groundwater recharge. T6eBiofilterGap When considering biofilters, watershed managers need to close the gap between the potential shown at testsitesandthe'vrealworld'nnplementation. Asbiofilters become more popular, it appears that the gap may 47 31 0.228 0.136 0.133 124 0.037 0.011 0.006 ~,725 org/100 ml no[ delected (below 0.5) Inflow Conc. (m9~~) 30.3 0.13 0.04 0.06 0.345 0.352 o.ooss 0.0023 0.025 ~ r ~, r ~- r r r r '-- r ~ ' LJ r ~ r r r r r actuallybewideningratherthanclosing. Whenthe1995 King County field survey iscompared to an earGer 1987 survey by Homer, it is evident that the field condition ~ ofbiofiltershas actuallyworsened. Forexample,Homer reported that 59% ofbiofilters that he surveyed were in "good" condition in contrast to the most recent snrvey, wLich found that only 27% could be so classified. King County's study concluded that in a typical subwater-~ shed, the poor design, construction and maintenance of biofilters cuts potential downstream pollutan[ reduc- tion potential by half. . Clearly, biofilter perfortnance can only be improved if more effort is placed on construction inspection and maintenance enforcemenL Given the poor experience with biofilter implementation, it seems reasonable to requue pedormance bonds for bio5lters to ensure that they are cotrectly installed, vegetated, and protected from construction sediment As good prac[ice, the perfoimance bond wotild be released after a satisfac- rory field inspection two years after initial constcuction. In most cases, reinforcement plantings, sediment re- moval,regradingandotherspotrepairs wouldbe ~eeded before final acceptance. Soil testing is anoWeruseful requirement to confum soil permeability and fertility and the distance to the water table. Such data should be submitted prior to actual design to detertnine whether [he biofilter will ultimately be dry or wet, and consequently, what spe- cific conshvction methods and vegetative stabilization techniques are needed.Iastly, maintenance agreements should clearly assign theright ofinspection and correc- tive maintenance to local govemments, so that they have an enforcement mec6anism to compel routine maintenance. - Basic biofilter design cri teria are continualty evolv- ing. Based on recent monitoring studies and field expe- rience, several additional design refinements seem ap- pmpriate: Limit biofilter lengt6 to no morethan 200 feet fm individual units (although designers need to con- sider local conditions such as rainfall and various intended uses of the biofilter). • Requireapoolorotherfoanofpretreahnentatthe upper end of a biofilter if it receives concentra[ed: inflows (to prevent a sediment buildup at the top oftLe swale). • Limitlongitudinalslopesto]%orgeateyunless it is inten6onally designed as a'~veP' biofilter. • Develop more specific design criteria for'~vef' biofilters that govem ponding, wetland stabili- zation, check dams and other criteria. • Requiremorestringentgeo-technicaltesringprior to design and coashuc[ion. Lastly, as Arnold (t997) notes, it is esseutial ro properly train public works crews on the best techniques formaintaining the long-tean perfor- manceofbiofilters. -TRS References Amold, G.M. 1997. StormwaterQualityMaintenance Management: Maintenance Practices and StaJJ Educafion. Resources Management Branch, Se- attle Public Utili[ies.58 pp. Goldberg,J.1993. DaytonAvenueSwaleBiofiltratian Study. Seatde Engineering Depaihnent. Seattle, WA. 67 pp. Homer, R., et a1.1988. Biofiltralion SystemsforStorm- waterRunofjWater Quality Conbol. Washington Dept. Of Ecology. 84 pp. KingCounty.1995.EvaluadonojWaterQualityPondr ~ and Swalu in thelssaquah/EastLakeSammamish Basins. KingCountySurfaceWaterManagement and WashingtonDepartrnen[ofEcology. Seattle, WA. 75 pp. Reeves,E.1995. "PerformanceandConditionofBiofilters inthePacificNorthwest "TechnicalNote30. Wa- tershed Pra[ection Technigues 1(3): I 17-119. r Lg DRAFT STORM WATER POLLUTION PREVENTION PLAN for RORIPAUGH RANCH MASS GRADING ACTIVITIES Temecula, California Prepared for: ASHBY DEVELOPMENT COMPANY, INC. 470 East Harrison Street Corona, CA 92879 Phone: (909) 898-1692 Prepared by: DAVID EVANS AND ASSOCIATES, INC 800 North Haven Avenue, Suite 300 Ontario, Califomia 91764-4915 Phone (909) 481-5750 August 23, 2001 ~6 Table of Contents Section i Project Description ...............................................................................................................1 Site Description ....................................................................................................................1 BMP Objectives ...................................................................................................................2 Section 2 Best Management Practices (BMPs) ..................................:................................................9 Section 3 Inspection and Maintenance Responsibility .......................................................................14 Section 4 Storm Water Sampling and Monitoring ..................::.........................................................16 Section 5 Storm Water Pollution Prevention Plan (SWPPP) Worksheet ..........................................18 Appendices: A - BMP Details B - SWPPP Site Plan C - Erosion Control Plan D- San Diego Basin Plan Water Quality Objectives ~~ '1 ., ' Section 1 ' Site Description ~ The project site of the Roripaugh Ranch Specific Plan consists of approximately 809.7 acres of land located in the City of Temecula and the County of Riverside. The northeastem section of the project site (covering 185.7 acres and referred to as the "Panhandle") is located at the northeastern ~ edge of the City of Temecula. The rest of the site (634 acres) is located within the County of Riverside, just east of Temecula. The majoriTy of the project site is used for dry farming, with ; limited sand and gravel extraction activities, vacant lands, an abandoned airstrip, hangars, storage sheds, and residences. Figure 1 shows the location of the project site. ; Based on the Phase 1 ESA, there aze no significant levels of agricultural chemicals on the site. There aze tires, old equipment, pipes, and dntms and containers on the centrai section of the site which contain waste oils, fuel, and paint. In addition, there aze fuel tanks and aboveground tanks ; at various locations. Small areas of petroleum staining were also observed at scattered locations neaz the airstrip and at the central section of the site. All above ground debris, wastes, equipment, and tanks would be removed and disposed at an approved waste facility. Remediation of identified ' soil stains would also be made in cooperation with appropriate regulatory agencies, prior to any grading activities within these azeas. ; Project Description The proposed development for the project site would include 1,721 residential units, an elementary ~ school and middle school, neighborhood commercial and institutional uses, a fire station, parks, and open space. The Roripaugh Ranch Specific Plan provides guidelines and standards for ihe development of these land uses on the project site. ~ The development of Roripaugh Ranch would require mass grading of the project site, prior to more ~ precise grading plans for various tracts and pazcels. Areas designated for open space, azeas for preservation azound Santa Gertrudis Creek, and those located within the 100-yeaz floodplain of Long Valley Wash would not be subject to mass grading activities. The existing residences at the ~ northem edge of the site would also be retained and the immediately surrounding azea would not be graded. Ali other structures would be removed and the azeas subject to mass grading. No paved azea or buildings aze proposed as part of mass grading acrivities ~ Materials and Equipment - Materials that would be brought to the site would include gravel, water tank, fuel tank, soil binders, hydroseed, sandbags, fencing materials, and pipes. Equipment and ~ vehicies that would be utilized would include graders, bulldozers, dump trucks, water hvcks, and scrapers. ~ Loading and Access - Construction materials would be transported to the site and unloaded. Materiai unloading and access azeas aze located at various locations on-site, as shown in SWPPP Site Plan. All construction materials will be delivered to and stored on pallets in designated ' storage azeas on site. ~ 1 ~p~ ' i~ u ' Equipment Storage and Maintenance - Equipment will be stored at various locations on-site, as , shown in SWPPP Site Plan. Equipment fueling, cleaning and maintenance will take place within designated staging azeas. Major equipment overhauls or repair would take place off-site. Sanitary facilities will be maintained and treated regularly. ~ Materials Storage and Disposal - Materials will be stored on pailets in designated storage areas until use. Wastes will be placed in dumpsters at designated waste containment areas and emptied ; weekly. Excess excavated soils and construction waste materials will be temporarily stockpiled on site, prior to disposal offsite into an approved waste facility. ' BMP Objectives This Stormwater Pollution Prevention Plan (SWPPP) has been developed in accordance with the ' requirements of the Califomia State Water Resources Control Board and the City of Temecula, and in compliance with the National Pollutant Dischazge Elimination System (NPDES) General Permit ' for Construction Activity. The SWPPP identifies erosion, sedimentation and pollution control measures that would be implemented durine mass gradine activities of the project site for Roripaugh Ranch, and seeks to minimize the discharge of pollutants into the stormwater and ' existing drainage channels to the maximum extent practicable. Figure 2 shows the existing drainage pattems through the site. Figure 3 shows the off-site areas that drain into the site. ~ Figure 4 shows the proposed mass grading plan for the site. It is estimated that 8 million cubic yazds of cut and 7 million cubic yards of fill materials would be needed for mass grading activities. As discussed above, the various activities or substances utilized during mass grading of the site ~ could result in pollutants, other than sediments, entering the storm water dischazges. These include loose soils, sediments, organic materials, wastes, equipment/vehicle fluids, construction materials, soil amendments, and other materials brought to the site. Measures to prevent poilutants from ~ entering the storm drain system aze discussed below. The owner and coniractor aze responsible for taking the steps necessary to minimize or prevent any dischazge in violation of the NPDES General Permit. Thas, it will be of critical nature that the contractor and owner are educated in the BMPs, ~ to ensure their implementation. ~ ~ ' r ~ ' 2 ~~ VICINITY MAP N.f.4. Figure 1 VICIlVITY MAP Paa~cr ~ocanoN Z~v 3 ~ ~ ~ ~ 1 ' ' r ~ , : ' , ~ ' r ' r r ~ ~ ~'•~ ~ ~o ,.`:..-.....' r- / - I ~ ~~ ~-~ °o ~. ~ ~~ ~~...~ .~ ~,~ I iN ' /. ~\... ;~ , ~ " "i , ~ O'NY \ • ~ \ 0 e ' `_ ~ . ~ ~ ~, ' \ ' ] ~ ` , \ ' •'~ . ' ~ '.\ ~~~~ ~ ~~ .~ ~ •• \' ~~~~'~ N r~ °g~ ~ ~ ---~~- ~z - ~ i ~., ~ i . A c~ ~ z ~ : ~ ~ ~ ~~ ~ w ~~ . -••\ m I :U /j I I ;~ '~~. i i~ ~~ . / . I •\ ~ ` \ N N 7 O V. N ~. m D ~ lLL ~ C C N UJ •K 'x W W ` g ~ m$ ~ a 4 2`~ ~f I ,' ~ !I r~ ~~ ~' 1~ 1~ , ~ ~ , , r r ~ r ~ ~ , ~ , ,, :.>>.. ~,: ~,-~~ ,:a ,, M ,r "~ ~ ~a wo x ~ ~ ~ z 0 ~ ~ ~ 2~v 5 ~i , ~ ~ I ~ ~ ~ ~ ~ ~ , ~ r r r r r r ~ ~ V J z UJ uj ~J o ~'1 ~ LL > ¢ O LL V zz ~ ~a ~~ U W ~ W ~~ a U ttl ~ ~~-~ z~ , ~ ~ ~ ----- ~ ~ I O ~ Z . . . . F- .~~~. ~•.~•z~r,~ . ~, . . . . . . . SS~ .~. . . :;;:::::::- .~.~. . ~ . . . ... ~~~~~........ :~:~. : . ::.. .F:; i- •~•~. . . . . . •,~-~ : ~ : i: : . . . . ., .su~. .I.: . . . . . .~~1 . :;: ~• . t . ~ i : ~, . ~,.~:~ r. , ly i z O.~ ~ i ~~~`_' ~ W ~ ~:~: ' -~~i{ s ~.,~:' ~ :n~l.~A 1 ~=~• 3 • 4'•1~lT i -~~ ~_~ ~ ~~ ; .~.~~ ~ t~= ~ , ~_, ~ Figure 4 MASS GRADING PLAN ---i------i ~ ~ ~ ~ ( ~ i . . . . . . . I ...n.~.F y. . . a, ~ . ..~'~i.i. . . .~i' i ~~ ~. ~.~::::;~ ~I ... _~ :`: . --~) ~s~ . I ~~ ~ .~-. ._ ~ °~ 1. .~ ::~~. z .~ . ~. _ . ~ _ .i~. ._ `°i •r• a .I~ . Z) :~ :: W, ~ :~ ~~ ~ . i .. a I , _~ n J Q (.3 6 2~3 i ,~ '' In order to minimize the possibility of introducing loose soils, debris, pollutants from construction ~ materiais and equipment, or vehicle wastes into the existing drainage channels and storm drain 'j system, the following general provisions will be implemented: + 1. All construction materials will be stored in designated azeas outside of any drainage path. ,! 2. All equipment will be fueled and maintained in a designated area away from existing or .~ proposed watercourses. The designated azea will be bermed to contain accidental spills. 3. The following additional BMP objectives will be observed: ^' • Good Housekeeping: Maintain a clean, orderly project site by putting construction wastes, demolition wastes, and trash in its proper place and avoiding fuel spills. '~ • Disturbed Areas: Cleaz land that will be graded within the. near term (within next six to 12 , months) and minimize new land disturbance during the rainy season. '~ • Stqbilize Areas: Provide temporary stabilization of disturbed soils after mass grading and ~~ permanent stabilization during finish grading and landscaping of the site. • Protect S[opes: Avoid disturbing steep and unstable slopes and natural channels. Safely ~ convey runoff from top of slope. Stabilize temporary and permanent channel crossings as ,~ quickly as possible and ensure that increase in runoff velocity does not erode channels. ~ • Wind Erosion: Graded areas will be watered regularly or stabilized at the earliest time possible ~ in order to minimize wind erosion. Stockpiled soils shall not be left on site for long periods of time. ' ~ • Sediment Contro[ Practices: Runoff from the site should be free of excessive sediment and ~ other pollutants. Detention basins shall be provided at various locations. Sandbags and silt fences will be installed in the nearby streets and along on-site drainages to reduce the amount of silt that could potentiaily enter the existing drainage courses on site and the inlets located at ~ the surrounding area. • Road Trackoff.• In order to reduce sediment h-acking onto the adjacent roadways, access to the ~ site will be restricted and on-site construction roads stabilized. • Sweeping: Sweeping of dry solids from paved areas exposed to precipitation or runoff. Operate street sweeper on paved roads adjacent to project construction azea on a regular basis, ' as necessary, and before any storms. '! • Upstream Runoff.• Divert azound or safely convey through the site. Diversions must not cause ~ downstream property damage or runoff diverted into another watershed. '~ • Vehicle and Equipment Washing: Will be done within the azea where berms are installed to collect wastewater and keep it away from the storm water system. l ~ '! 7.~°r r~ . ~ • Materials Storage: Protect construction materials by covering them with a tarp when storms ~' aze expected. Cover areas where liquids or solids in containers are stored. Anchor these tarps and cover with rocks or stakes. All potentially hazazdous materials will be collected properly ~ and stored in designated azeas on site prior to the disposal by owner or contractor at an authorized disposal site. ; • Outdoor Storage: Store containers, drums, and bags away from direct traffic routes to eliminate accidental spills. Designated azeas shall also be located away from drainage channels. ' • Waste Containment: Dispose wastes in designated azeas and keep storm water from flowing ~ on or offthese azeas ~ , ' r ~ i i r r r r r r r 8 . 2~~ , 1~ ~ ~ ~~ Section 2 Best Management Practices (BMPs) The following Best Management Practices (BMPs), in accordance with the California Storm Waste Best Management Practice Handbook and the City of Temecula guidelines, are applicable to this project. They will be utilized to prevent or reduce the potentiai for contamination of storm water during mass grading activities proposed on the project site. i 1. Non structural BMPs ~ The following non-structural BMPs shall be practiced on-site during mass grading activities: ~ BMP 1.1- Education of Crew Prior to the mass grading activities, the contractor and owner will provide educational materials ~ and training for construction crew who will be responsible for general housekeeping practices to protect stormwater quality. They wiil distribute the BMP fact sheets from this SWPPP (Appendix A) to all site personnel. Training would be provided at start of grading activities. ; The training subjects will inciude appropriate storage practices, trash disposal procedures, and the correct methods for vehicle and equipment fueling and maintenance. ; BMP l.2 - Existing Vegetation Areas that would not be g~aded shall not be cleazed of existing vegetation. These areas include ateas to be preserved as open space at the western, southem and northeastem boundaries of the ~ panhandle, the azea surrounding the existing residences at the northern central section of the site, the 100-yeaz floodplain of Long Valley Wash (approximately 218-feet wide corridor along the wash), and the habitat conservation azea at the northeastem section of the site, traversed by ~ Santa Gertrudis Creek. These azeas shall be left undisturbed. BMP I.3 - Scheduling ~ The contractor shall phase grading to minimize the amount of exposed azea at one time. Areas should not be cleazed until grading is scheduled to begin. Exposed azeas should be stabilized ~ as soon as grading is complete. Grading shall be minimized during the rainy season (October to April), to the extent possible. ~ BMP 1.4 - Liner Contro[ ~ Existing trash and debris found on the site would be wllected and disposed prior to any grading activities. This includes tires, drums, containers, trash piles, abandoned equipment, tanks, wood, pipes, concrete, as well as demolition wastes from abandoned buildings and storage ' structures. ~ During grading, trash and solid wastes will be coliected into covered dumpsters and routinely disposed off-site to reduce the potenrial for pollution of drainage water. Wastes shall be stored in designated areas and shall not allowed to remain on-site for over two weeks. A street ~ sweeper shall be used on paved roads adjacent to project construction azea on a regulaz basis, as necessary, and before any storms. y,(o 9 ' ' ~ ~ BMP l. S- Slope Protectian Any slopes with disturbed soils or denuded of vegetation must be stabilized within two months of final grading completion, so as to inhibit erosion by wind or water. Stabilization shall , include planting, use of chemical soil binders/stabilizers, blankets, netting, fiber rolls, temporary seeding, use of mulch, gravel, decomposed granite, or wood chips, temporary vegetation, permanent seeding, or other acceptable methods. Oil treatment or use of sodium ~ chloride is not acceptable. Exposed slopes would also be terraced to slow down runoff and allow sediment settlement. Trackwalking, raking, and disking along the slope would slow down runoff. ~ BMP I.6 - Graded Areas Graded areas shall be subject to daily surface watering to reduce fugitive dust and wind ' erosion, until temporary or permanent stabilization is provided. ~ BMP l.7 - Hazardous Materials Hazazdous wastes present on-site shall be collected and disposed in accordance with existing regulations. Any soil remediation activity shall be conducted in coordination with regulatory , agencies and in compliance with pertinent regulations. Any hazardous material used for the mass grading activities at the site shall be transported, ~ stored; used, and disposed in accordance with existing regulations. BMP l.8 - Truck Circulation ~ Vehicle, equipment, and truck access shall occur only at designated access roads, with material loading and unloading within designated staging azeas on the site. Trucks hauling soils and wastes shali be covered when leaving the site. , BMP 1.9 - Fueling and Maintenance Vehicle and equipment fueling, washing, and maintenance activities sha11 be conducted within ' designated azeas. Crew shall be instructed to avoid topping off of fuel tanks and shall use secondary containment, such as drain pan or drop cloth to catch spills, when fueling. The contractor shall comply with federal and state regulations regazding . construction, use, and ~ maintenance of fuel tanks. Major equipment overhauls or repair would take piace off-site. BMP I.10 - Stockpiles ' Stockpiles of excavated soils shall not be stored for extended periods of tiine. They shail be covered with tarp, stabilized through vegetation or chemical means, or transported for off-site ~ disposal. BMP I.11 - Sanitary Facilities , Sanitary facilities shall be weli-maintained and wastes treated or disposed in accordance with State and local requirements. Regular service and disposal for these facilities should be provided. ' 2~~ , io , ,~ ~ ~ ~ ' i ~ ~ ~ ' ~ ~ ' r r r ' ~ ~ r BMP 1.12 - Accidental Spi11s Where pollutants have been released on-site by accident, maifunction, leakage, or spill, the pollutants shal] be immediately contained and properly cleaned up prior to a storm event. 2. Structural BMPs These structural BMPs shall be provided on-site, as shown in the SWPPP Site Plan in Appendix B and the Erosion Control Plan in Appendix C. BMP 2.1 - Access Roads Designated access roads shall be designated and cleazly signed. The contractor shall stabilize all consttuction entrances and on-site access roads would be gravel paved. BMP 2.2 - Staging and Storage Areas Staging areas for on-site equipment and materials storage shail be designated at specific locations on the site, which are located away from access roads, d'uect traffic routes, and drainage channels. These azeas shall be bermed to prevent runoff from entering or flowing across these azeas. All equipment and materials shall be stored in this azea, and vehicle fueling, washing, and maintenance shall be confined to these azeas. Fuels~ hazardous materials, and other pollutants shail be stored on water-tight containers or buildings or under a water tight roo£ Conshvction materials shall be stored on pallets and shall be covered with tarp when storms are expected. These tarps and covers shall be anchored with rocks or stakes. All potentially hazazdous materials will be stored in designated areas on site and collected properly prior to the disposal by owner or contractor at an authorized disposal site. Similariy, waste storage azeas shall be designated on-site and bermed to prevent runoff from flowing in or through them. BMP 2.3 - Clearing Limits L'units of grading shall be mazked along azeas preserved for open space, the 100-yeaz floodplain of Long Valley Wash, and the azea along Santa Gertrudis Creek to prevent disturbance by grading activities. In addition, temporary limits shall be placed around small azeas of petroleum staining that were observed at scattered locations near the airstrip and at the central section of the site. Remediation of identified soil stains would also be made in cooperation with appropriate regulatory agencies, prior to any grading activities within this azea. BMP 2.4 - Inlet Protection In addition to sand bags, inlet protection shall be provided for azea drains and curb inlets near the project site (downstream of site). These may consists of a filter fabric fence, block and gravel filter, gravel and wire mesh filter, sand bag barrier, or excavated drop inlet sediment trap. ~~ ~~ ' ' BMP 2.5 - Temporary Detention Basins Temporary detention basins would be located at various locations throughout the project site , and constructed at the start of grading activities. These basins would be located within the relatively same area as the proposed permanent detention basins and would be located neaz ; existing drainage channels and in azeas that would collect sediment and debris from runoff prior to entering the drainage outlets off-site, as well as serve to reduce runoff velocities. Basin outlets shall be provided with protection to prevent erosion and scour of the embankment and ; channel. BMP 2.6 - Runojf Diversions ~ Offsite runoff that enters the site at the southeastern comer neaz Butte~eld Stage Road and at the northwestem section of the site at Pouroy Road and Murrieta Hot Springs Road shall be diverted to flow along the southem and northem site boundaries, respecUvely. This diversion , ' would prevent runoff to flow across graded azeas on the site. This diversion shall be temporary until storm drain lines are installed along Murrieta Hot Springs Road and along the extension of Calle Chapos and Butterfield Stage Road. The runoff from the nahual watershed azea ~ located east of Tract 29353 and the site will be intercepted by sedimentation basins before discharging into Long Valley Wash. , BMP 2.7 - Channel Crossings Channel crossings shall be provided at Santa Gertrudis Creek and Long Valley Wash to allow ~ equipment and vehicles to cross the creek for on-site soil movement. The crossings shall be marked and all equipment and vehicle drivers informed of their locations. One crossing would be located at the azea where Santa Gertrudis Creek crosses the proposed Nicholas Road ~ extension and a second crossing would be located where Long Valley Wash crosses the proposed Butterfield Stage Road extension. ; BMP 2.8 - Sandbags Sandbags will be installed around storm drain inlets located along designated access roads, and neaz the site boundaries (downstream of the site) to reduce the amount of silt that could ~ potentially enter. the inlets located in these azeas. Also, sandbags will be placed along the edge of the channel crossings to minimize the amount of silt entering Santa Gertrudis Creek and Long Valley Wash at these areas. BMP 2.9 - Slope Drains ' ~ Slope drains shall be provided at various locations throughout the site in azeas where mass grading leads to the creation of steep slopes. These slope drains shall collect runoff from the top of slopes and convey the stormwater to the bottom of the slopes, without causing erosion , along the slopes. , BMP 2.10 - Earth Dikes ~ Earth dikes shall be provided throughout the site to divert runoff from directly entering the existing drainage courses on-site. ~ BMP 2.II - Silt Fences ; iz Z~0. ~j ,I Silt fences shall be provided along the grading limit line, to prevent sediment and silt from entering the designated habitat azea at the northeastem section of the site. The silt fences aze 'i proposed along Butterfield Stage Road (on the west) and the boundary of the habitat azea and the northernmost tract boundary (on the south). 'I BMP 2.12 - Outlet Protection Outlet protection shall be provided where on-site stormwater discharges off-site. These are ' located along the boundaries of the site at Long Valley Wash, Santa Gertrudis Creek and other ~ drainage washes. Outlet protection shall consists of a rock splash apron, grouted riprap, or concrete rubble at the point of discharge and would be designed to reduce flow velocities and ~ prevent the scouring of soils at the adjacent properties. I More specific discussion of these individual BMPs is provided in Appendix A. ,I Erosion and sediment control ESC measures should be installed as soon as reasonabl ( )~ y practicable ~ following construction crew mobilization and site clearing, and shall remain in place until fine 'j grading, planting, and paving of project construction site is complete. An erosion control plan with details has been prepared and included in this report and shall be implemented by the contractor as ~,. necessary. Since this SWPPP has been developed for mass grading activities only, it does not include ~ construction or post-construction BMPs. Permanent unprovements along Long Valley Wash, '~ Santa Gertrudis Creek and other on-site drainages are also not proposed at this time, except for the temporary detention basins which would be converted to permanent detention basins at a later date. ~ ~ ~ ~ I~ ~ ~~ 13 7~" 1' ; 1' Section 3 '~ Inspection and Maintenance Responsibility for BMPs The following procedures will be performed in order to determine the performance of the '~ previously outlined Best Management Practices and ensure that they aze being implemented. , I l. Site Inspections The owner and the City of Temecula will perform site inspections required by the general permit. , The purpose of the inspection is to determine the effectiveness of existing BMPs to analyze the need to add, delete, or modify any BMPs and to determine maintenance required to keep any shuctiual BMPs functioning properly. A written record of the inspection results will be kept, '~ including the date of the inspection; the person(s) who performed the inspection, the observations, and the actions taken. Forms have been provided at the end of this SWPPP for the inspection ~ i reports. Specifically, the following activities would be made: ~ • Examine integrity of containment structures and BMPs I • Verify adequacy oftrash receptacles ,I • Verify waste disposal praclices • Look for evidence of spills and resulting clean-up procedures ,~ • Examine sediment accumulation at BMPs ' • Look for evidence of escessive downstream sedimentation , • Look for evidence of construction materials washed off-site '~ Initialiy, an inspection shall be conducted after site cleazing is complete and erosion and sediment control measures have been installed. After which, inspections shall be conducted before and after ' storm events (rainfall of 0.5" or more) and once each 24-hour period during extended storm events. Pre-storm inspections will ensure that pre-storm BMPs are properly installed and maintained. ' Post-storm inspections would ensure that BMPs have functioned adequately. Repairs and design changes shall be implemented as soon as feasible depending upon field conditions. Equipment, materials, and workers must be available for rapid response to BMP failures and emergencies. All ,i corrective maintenance to BMPs shall be performed as soon as possible after tkie conclusion of ( each storm, depending on worker safety. ,~ If the inspector observes improper construction measures or pollution, the inspector shall inform ~ site personnel of proper or correct way along with follow up inspections and further training. 2. Repair and Maintenance The following activities shall be conducted after inspections for repair and maintenance of the '~ BMPs: , • Sediment will be removed from sandbag barriers and iniet protection when sed'unent '; reaches 1/3 oftotal available depth. ~ ~ ~ 14 '' ~~ ; ~ ~ ~ , ~ r ' ~ r ~ ~ ~ 1 r r r i r • Sediment shall be removed from detention basins when sediment reaches 1/3 of total available capaciry. • Sediment and silt shall be removed from silt fences after major storm events. • Stabilized areas that aze eroded shall be reseeding or mulched. • Any damaged or disrupted BMP will be replaced or repaired within 48 hours of discovery. 3. Cert fcation of Compliance Based on the results of the inspections, compliance with the requirements of the NPDES General Permit and this SWPPP will be certified annually and completed by July 1 of each yeaz. If the inspection indicates non-compliance, actions to be taken to achieve compliance, and a time schedule in which compliance is to occur should be provided. 4. Record Keeping Records of all inspections, compliance certifications, and non-compliance reporting, and registered Professional Engineer certifications, as required, will be retained on-site during the enfire duration of mass grading activities and for three years after the date the reports aze generated or after project completion. In addition, records of maintenance acrivities, as well as material spills and clean up actions, will be kept by the owner. 5. Plan Review and Modifications This pian will be revised if an inspection indicates a need to drop an ineffective BMP, add a new BMP, or modify an existing BMP. If there is a new, deleted, or relocated activity, the plan will be modified if the change significantly affects the amount of contaminants in the storm water. 15 ~~ i ' 1 '~ Section 4 ~! Storm Water Sampling and Monitoring ~ Stormwater sampling and monitoring shall be conducted, as required under tl~e California State ," Water Resources Control Board's NPDES Generai Permit for Construction Activity. The project site for Roripaugh Ranch does not discharge directly into a water body ]isted in Attachment 3. ~ Therefore, this SWPPP does not include procedures for sampling sedimentation, siltation, and '! turbidity. The majority of the site is used for dry farming, with small areas of residential use, storage, and airstrip. Based on the Phase 1 ESA, there aze no significant levels of agricultural chemicals on the site. There are tires, old equipment, pipes, and drums and containers on the central section of the site, which contain waste oils, fuel, and paint. In addition, there aze fuel tanks and aboveground tanks at various locations. Small areas of petroleum staining were also observed at scattered locations near the airstrip and at the central section of the site. All above ground debris, wastes, equipment, and tanks would be removed and disposed at an approved waste facility, prior to grading activities. Remediation of identified soil stains would also be made in cooperation with appropriate regulatory agencies, prior to any grading activities within the identified areas. Heavy equipment and vehicles would be brought on site for use during grading activities. Oil, grease, and petroleum hydrocazbons from these equipment aze potential stormwater pollutants. ' Construction materials would also be stored and used on-site, and could pollute the stormwater. ~ 1. Stormwater Monitoring During mass grading activities, stormwater sampling will be conducted to verify the presence or absence of non-visible pollutants in the storm water. Runoff samples will be collected from at ' least two storms during the wet season (October 15 to April 30), Samples will be taken at the storm drain outlets (dischazge points) during the first two hours of dischazge during a rainfall event, with safe access to the site and sampling locations ensured. The sampling locations ' correspond to the points on-site which dischaige on-site tunoff into off-site facilities, as shown in the SWPPP Site Plan. The samples will be analyzed for pH; total dissolved soils, specific ~ conductance, biological oxygen demand, nitrates, and oil and grease. Sampling and stormwater analysis shall be conducted by trained personnel. Samples will be ~ coilected and preseryed in accordance with Method 1060 of Standazd Methods for the Examination of Water and Waste Water (20`~' Edition). Sampling wouid generally involve the following tasks: ' • Monitor weather forecasts and alert saznpling crews when probability of rain exceeds 70 percent during the next 24 hours and is likely to create a sampling event. ^ Samples aze to be taken during first two hours of dischazge and collected from discharges that ~ occur during grading operations in daylight hours and when preceded by at least three working days without stormwater discharge. ^ At start of sampling event, disperse sampling crews to designated outfalls with sample kit ; provided by the environmental labotatory. r,q.?7 !/' ' 16 ~i ~~ . Sampling crew shall collect manual grab samples. To collect samples, place sample container with open-end facing upstream directly into the stream of water. Be sure not to contaminate ,~ the inside of container. Do this for each container in the kit. ^ Once samples aze collected, sampling crew will complete test sample log and chain of custody 1 report (provided in Appendix D). ': • Sample crews will deliver samples to SWPPP manager. SWPPP manager will assure delivery of samples to designated environmental laboratory within 24 hours of sample collection. ,! Z. Monitoring of Spills In addition, other dischazges that aze idenrified through visual monitoring to be potentially ,~ contaminated by pollutants shall also be sampled and monitored. If a pollutant spill cannot be fully ~ contained and cleaned prior to a rain event, stormwater sampling shall be conducted. When the leak occurs during a rain event, sampling shall be conducted at that time. Sampling shall occur at ,~ the point that drains the contact areas, within the first two hours of discharge (runof~ from rain events, and during the daylight hours (sunrise to sunset). However, no sample is required if the sample location(s) cannot be safety accessed. ' In addition, a location that is not affected by the poilutant shall be selected for collecting an ' uncontaminated sample for comparison purposes. This may include outlets that collect runoff from '~ undisturbed azeas on-sife, from area where run-on from offsite azeas are diverted around the site, or where there aze no activities that couid contribute to pollutants in the runoff. Test results will be kept on file at the site until filing of the Notice of Termination. ~ 3. Corrective Action ~ Corrective actions shall be initiated where stormwater sample test results indicate site runoff may cause or contribute to water quality exceedance, based on comparison of the test results with water ~ quality objectives of the receiving water body (as contained in the Comprehensive Water Quality Control Plan for the San Diego Basin). Appendix D provides excerpts of the Basin Plan which contain these water quality objectives. Corrective acrions may include repair of the existing BMP, ~ use of an alternative BMP, or implementation of additional BMPs (cover and/or containment) which further eliminate contact between stormwater and pollutants at the site or which retain polluted stormwater on-site for treatment prior to off-site release. ~ ~ ~ ,~ ~ '~ 17 i ' ~ ~ ~ ' r ' ~ ' ~ ' r ~ ' ~ ~ ~ ~ ~ ~ SCCt10II 5 Storm Water Pollution Prevention Plan (SWPPP) Worksheet California Construction Ceneral Permit REVISIONS DATE NOI attached? [ ] Yes [X ] No Worksheet 1. Project Information Project Name: RORIPAUGH RANCH Project Location: Street Address (or Equivalent): Adjacent to northeast corner of the City of Temecula CiTy: Temecula Courity: Riverside Zip Code: 92591 Project Owner: ASHBY USA, LLC Contact Person: JUSTIN ASFIBY Phone No. (909) 898-1692 Owner's Mailing Address: Street Address (or Equivalent): 470 EAST HARRISON STREET City: CORONA County: RIVERSIDE Zip Code: 92879 [/] Identify responsible personnel: [/] Implementing and revising the SWPPP: Justin Ashby [/] Inspecting equipment: Justin Ashby [/] Regulaz inspections of BMPs: Justin Ashby [/] Training employees about BMPs affecting their job: JusHn Ashby [/] Stormwater sampling and monitoring: Justin Ashby List all Contractors and Subcontractors responsible for implementing SWPPP for the project: NAME CONTACT PERSON ATE WORK BEGINS DATE WORK ENDS Ashb USA, LLC Justin Ashb October 2001 October 2002 18 v ~ ~ ' ' ~ ~ ' ' Worksheet 2. Project Site Map Requirements Please Check the Boxes, and provide supporting information as requested: [/] Topographic Base Map Attached? Map shows: [/] An area extending one-quarter mile beyond the property boundaries of the construction site: See Figure 1- Vicinity Map [/] The boundary of the construction site. Construction Area = 809.7 acres. See Figure 4- Mass Grading Plan and SWPPP Site Map (Appendix B) [/] Nearby surface water bodies, including watec courses, wetlands, springs and wells: See Figure 2- E~cisting Drainage and SWPPP Site Map [/]. The location(s) where storm water drains onto or off of the property. See Figure 2- Existiag Drainage and SWPPP Site Map [/] Boundary of off=site areas that drain into the construction site. See Figure 3- Regional Hydrology , [/] Site map(s) attached? Maps show: [/] Temporary storm water structures used during consWction. ~ See Erosion Control Plan (Appendiz C) (/] Areas use to store soils and construction waste. See SWPPP Site Map. , [/] Areas of cut and fill. See Erosion Control Plan ~ ~ ~ ~ ~ ' ~ ~ ~ ' [/] Drainage patterns and slopes anticipated after major grading activities, including the location of storm water structures to be constructed on the property (e.g., storm drains, detention ponds, channels). See Figure 4- Mass Grading Plan and Erosion Control Plan [/] Areas of soil disturbance. See Erosion Control Plan [/] Locations of potential soil erosion requiring BMPs during construction. See Erosion Control Plan [/] Existing and proposed paved azeas and buildings. No paved area or buildings are proposed as part of mass grading activities Existing Area; 0_0 percent of site Proposed Area: 0_0 percent of site [/] Estimated runoff coefficient beFore construction: 0.65 afrer construction 0.76 (See the local municipality for approved runoff coefficients for your community). [/] Locations where storm water structures and controls will be built to control storm water pollution after construction is complete. See SWPPP Site Map [/] The boundary of the drainage azea upstream of each location where storm water leaves the property. See Figure 3- Regional Hydrology [/] Any vehicles storage and service area. See SWPPP Site Map [/] Areas of existing vegetation. The existing vegetation on-site is shown in Figure 5 below. 19 ~ I '' 1 '~ , I '~ 1~ '' , i '~ '~ f '~ ~ ~ ~ r i M r r a ~~ i 1' o% ~ ~ (B 2 ~ cfl r- Q I ' ~ ,~~' ~ ~ _`\~ ~ ~ ~~ ~~ ~ T ~ ~ ~ ~ ~~ ~ I ~ ~ ~ I m 0 U ~ ` c U v ; ~o ~ ~ i ~ ~o ~ ~ ~ a I~ Z 9 I U /- I ~ ~ O Y ~ ~ `\\~ ~ _ _c ~ ~ ~,-~ - . ~~_ ~z LO a~n ~ . ~" F W ~ ~ z ~, ~ w zo `~~ i, '' 'I Worksheet 3. Inventory of Contractor's Activities ~ and Special Conditions '' Provide a description of contractor's activities that could result in the discharge of pollutants in the storm water ~ runoff for the site. In addition, provide a description of special site conditions that may impact pollutants in '~ storm water dischazges. ' Contractor's Activities '~ [/] Dascribe toxic materials that are known to have been stored, disposed, spilled, or leaked in significant ~' quantities onto the construction site: See Section 1, Site Description ''i [/] Describe construction materials, equipment, and vehicles that come in contact with storm water: See Section 1, Project Description [/] Describe construction material loading, unloading and access areas/ activities: See Section 1, Project Description ~ [/] Describe equipment storage, cleaning, and maintenance areas/activities: See Section 1, Project Description [/] Describe storage and disposal of construction materials (on-site and off-site): See Section 1, Project Description ' Special Site Conditions ~ (/] Describe storm water structures and controls on the site prior to construction and how these structures/ controls will be integrated into the SWPPP to reduce sediment and other pollutaats in storm water ~ discharges: No storm water structures or controls exist on the site. Temporary detention basins would be ~ located at several locations on-site. These basins would be converted to permanent facilities as part of future site development. ~ (/] List materials/ waters other than storm water which will flow from the site during dry weather, the approximate amount of flow, and methods for preventing other dry weather flows: ~ No dry weather flows wi11 be generated on site by this project. ~ ~ 21 ~ Ll , ~ 1 ' 11 ,~ U I Q L I ~ ~ L ~ iy ~ C W ~ ~ v v N ' L x ~ ~ ~ r ~ ~ ~ ~ ~'~.. ~ .. ~ ~a a ~U v ~ ~ U v ~ ti N y h a V ~ ~ ~ Ca ~' o ~ ~ ~ i. y O y w ~ . w M ~ N O y .~ .c ~a x ~ O w 3 .5 N y y ~ v 4 ~ a ~? o r, ~~ G a^.+ ~ ~ H ~ O ~ ~ ~ ~ N ~ ~ ~ N " U 3 w 'l7 p, ~ H R ~+ N •y ~' w ~ Y 'n 0 ~ 6 ~~ _~ a~ m Q U ~ /\ N ~ f.n ~ o ~~ P ~F•°~ ~ ~ ~ .~ v~i ~ U y ~ ~ ~ ~ ~ U a„ ~ U ~ O 4.. ~ ~ 0 O ~U ~ ~ ro ~ v o w° a •~ y > ~i a G. P~ ,-. vi ~ w ~ V1 y ~ m ~ C u 'b a; ^ a~ ~p R + ~ ~ L c3 ~ o c a ~' y o°0 ~ ~ ~ o A+ ~ ^~ y ~ L a+ m ~ W ^ Y ~ ~ 4+ ~ i+ p 7~ N 'n ~ a ~ ~ N V cC ~ p ~ y'i'~ y m b ~ • • ~• r~i d o . ~ ~ •N ~- ~~ t3 „ ~ p R~ e7 . C c7 ~ O ~ G ~ ~ ~ 4y ~ iJ ~ ~ ~ U ~ ~' [RI ~ C I U F a ~C M ~ ~ U G ¢ W 5 r~ 4 ~ U w , ~ y W ,~ m 5 m ~ ~ ~ ~ U w ~ ~ m s ~ ~ q ~ ~ U 2 L V ~ ' > U ~fy ~ L U ~ W ~ ~ r, ~ ~ ~ o '~ 3 ~ U S ~n N ~ ~ ~ ~ = ~y ~ ~ ~ V ~ G ~ ry Q~ N 3 ~ ~ I~V O q ~ ~ ~ 3" ~ >C N Q ~ ~ N O ~J~, '` y ry 1~ ~`1 1~ IY G `~ ~ U c~ .. . ~ ~ .F ~ ~ ti V V o >C >C DC p ~ R ~ U ~ ~ o ~z~ v = o yC DC SC DC ~AN U ~~ [ ~ ~' N a+ ~ U ^ ~. g s y ~ U °' o p . U ~ U 3 0 N ~ bD . ~ O 4 ~ ` , c~t % G. ;~ b y O y ~ ~'' ~I. ~' 'a fi .L'i tR F' N ~ U .y •~ ' ~~ ~ N ¢ ~' ~~ ° ?~~3 ~ ~'' ~~ ~. ~° ~ ~ ~y y E ~ ° ~ G ~ ° ° ? ° '-' " ti o x o o ~ 2 ~, . Y - ~' ~ Y . ~ ~ y y ~ o a•c q`° ~ ~ a o ~ ~a y o . . . ~ ~ ~ N • ~ y a~~1 ~ O~ o cd ' C~ ~ `~ N Q. y N o n' ^ ~'O o F~ v E a~3 ° 3 ~ 7 ~ ~`a w o `a E v~ ~'o ° 6~ ~ U N ri ~ vj N N ~ ; '' Worksheet 5. BMPs for Erosion and Sedimentation Control ~~ [/] Describe the source and composition ofthe existing soil and fill material ~ (Soil Report Attached? Yes X No _~ ~ No fill materials are required for this project. Only native soils available on site will ; be used for fill. Existing soil is sandy loam. ' [/] Provide a site map showing locations where BMPs for erosion and sediment control aze placed. This map should be updated when BMPs are revised to meet evolving construction conditions. Provide a brief description of BMP selected, and, if ; appropriate, attach modified fact sheets or additional information for erosion and sedimentation control BMPs. , ' ' ' ~ ' ~ , ~ ~ r These BN1Ps are discussed in Section 2 and suromarized in the table below. / DESCRII'TION OF BMPs FOR EROSION & BMPs SELECTED SEDIMENTATION CONTROL (ESC) SITE PLANNING CONSIDERATIONS ~ Scheduling BMP 13 Grading will be phased to minimize azea graded at one time. / Preservation of Existing BMP 1.2 ~ Vegetation Vegetation within areas proposed for open space will not be disturbed. SOIL STABILIZATION / Seeding and Pla~ting BMP 1.5 Steep slopes and graded areas will be stabilized after grading. Mulching PH1'SICAL STABILIZATION Geotextile and Mats ~ Dust Co~trol BMP 1.4 and 1.6 Regular watering of graded azeas, street sweeping of adjacent streets. ~ Temporary Stream Crossing BMP 2.7 Channel crossings at Santa Gertrudis Creek and Long Valley Wash would be rovided. ~ Construction Road Stabilization BMP 2.1 On-site construction roads wiil be gravel paved. / Stabilized Construction Entrance BMP 2.1 Access roads would be gravel paved to reduce vehicular sediment trackin onto roadwa s. ; 23 ~ i '~ 'i ~' ~ ' ~ r r ' 1 ~ ~ r ~ r ~ ~/ DESCRII'TION OF BMPs FOR EROSION & BMPs SELECTED SEDIMENTATION CONTROL DIVERSION OF RUNOFF / Earth Dike BMP 2.10 Earth dikes would be provided to redirect runoff flows Temporary Drains and Swales ~ Slope Drain gMp 2,9 Slope drains would be provided to direct runoff from the top of slo es to the bottom, without causin erosion. VELOCITY REDUCTION / Outlet Protection gIvip 2,12 Outlet protection shall be provided where stormwater discharges off- site to reduce velocities and revent scourin . Check Dams ~ Slope Roughening/ Terracing BMP 1.5 Steep siopes would be terraced and rough graded. SEDIMENT TRAPPING/ FILTERING ~ Silt Fencing BMP 211 Silt Fences would be provided along grading limits around Habitat area Straw Bale Barrier ~ Sand Bag Barrier BMP 2,g Sand bags would be placed at inlet structures near the site to trap sediment alon ex osed flowlines and alon the channel crossin s Rock or Brush Filter / Storm Drain Inlet Protection BMP 2.4 Inlet protection shall be provided at catch basins near the site to revent sediment from enterin inlets Sediment Trap ~ Sediment Basin BMP 2.5 Detentio~ basins would be provided atseverallocationsto trap sediments, to allow for geater ground percolation of runoff and to reduce runoff velocities. 24 , ~~ i ,' ~~ ~ , ' r r r ' r ~ ' ~ ~ ~ ~ ~ ~ Worksheet 6. Post-Construction BMPs Provide a site map locating control BMPs which will be constructed as part of this project to reduce storm water pollution after construction is complete. Selection of these and other post- construction BMPs may be guided using the Municipal BMP Handbook, and must consider site- specific and seasonal conditions. Provide on the worksheet below the BMP selected, the responsible party for maintenance and operation, and source for funding the operation and maintenance. / BMPs SELECTED MAINTENANCE RESPONSIBILITY FUNDING SOURCE FOR O&M TREATMENT CONTROL BMPs See Cha ter 5, Munici al Handbook) Infiltration Wet Ponds / Constructed WeUands To be provided affer permits from resource agencies are obtained Vegetated Swales and Strips ~ Extended Detention Basins Maintenance agreement between Owner, City and RCFCWCD Media Filtration Oil/ Water Sepazators and Water Quality Inlets Multiple Systems SOURCE CONTROL BMPs See Cha ter 4, Munici al Handbook Describe other measures which will be employed on the project site to control storm water pollution after construction is complete, and steps to be taken by the current owner to ensure that these measures are conducted. Temporary detention basins would be converted and maintained for long term use. Other post- . construction BMPs would be installed at a later date. 25 ~y 1~, Worksheet 7. Monitoring, Inspection and Maintenance Plan '1 / [ ] Describe maintenance/ repair efforts to ensure BMPs are in good and effective condition: ~ '' See Section 3, Inspection and Maintenance [/] Describe inspection procedures and record keeping efforts: '' S ee Section 3, Inspection and Maintenance Attached inspection forms are to be filled out. i ~ [/) A lI i nnua nspect on: ~ See Section 3, Inspection and Maintenance ~ ~ [/] Pre-storm Inspection: See Section 3, Inspection and Maintenance ~ [/] Post-storm Inspection: ~ See Section 3, Inspection and Maintenance ,' [/] Describe training program/ material for site personne] responsible for installing, inspecting, and maintaining BMPs: , See Section 2, BMP 1.1 ' ' ~ ~ • ~ ' r ' 26 2~' ; i ~ '1 ~ i ~~. ~ ' ~ ~ ~r ~ ' , ~ , ~ ' ~ , ' CeRification I certify under penalty of law that this document and all attachments were prepazed under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering the information, the information submitted is to the best of my knowiedge and belief, true, accurate, and complete. I am aware that there a~e significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name Signature This S WPPP was prepazed by: Name Signature 2001 Title Date Title Proiect Eneineer Date Aueust 23, 2'~ z~ ,I i '~ 'i ,~ i I '! '~ '~ i '' ~ ~ , r r r ' r r i Construction General Permit Inspection Checklist [ ] Regular Inspection Inspected By: Project: Date: YES NO Location Are the BMPs called for on the SWPPP installed in the proper location and according to the specifications for the SWPPP? Are all operational storm drain inlets protected from sediment inflow? Do any structural practices require repair or clean-out to maintain adequate function? If yes, indicate which ones: Are construction on-site traffic routes, parking, and storage of equipment and supplies restricted to areas specifically designated for those uses? Are locations of temporary soil stock piles or constrvction materials in approved areas? Do any seeded or landscaped areas require maintenance, imgation, fertilization, seeding, or mulching? Is there any evidence that sediment is leaving the site? Is there silt buildup in downstream storm dtains? Is there any evidence of erosion (i.e., rills and gullies) on cut or fill slopes? Is there any evidence of sediment, debris, or mud on public roads at intersections with site access roads? Is there any evidence of non-visible pollutants (oil, grease, fuel, etc.) or debris (construction materials or wastes) entering the storm drain system? If yes, explain. Does the SWPPP require revisions? If yes, explain: ~ ~8 [ ] Rainfall Eve~t Inspection (Before) [] Rainfalt Event Inspection (After) Rainfall _ Inches Construction General Permit Inspection Checklist [ ] Regular Inspection [ ] ~~ Inspected By: Project: Date: YES NO Location Are the BMPs called for on the SWPPP installed in the proper location and according to the specifications for the SWPPP? Are all operational storm drain inlets protected from sediment inflow? Do any structural practices require repair or clean-out to maintain adequate function? If yes, indicate which ones: Are construction on-site traffic routes, parking, and storage of equipment and supplies restricted to areas specifically designated for those uses? Are locations of temporary soil stock piles or construction materials in approved areas? Do any seeded or landscaped areas require maintenance, irrigation, fertilization, seeding, or mulching? Is there any evidence that sediment is leaving the site? Is there silt buildup in downstream storm drains? Is there any evidence of erosion (i.e., rills and gullies) on cut or fill slopes? Is there any evidence of sediment, debris, or mud on public roads at intersections with site access roads? Is there any evidence of non-visible pollutants (oil, grease, fuel, etc.) or debris {construction materials or wastes) entering the storm drain system? If yes, explain. Does the S WPPP require revisions? If yes, explain: `(~' Rainfall Event Inspection (Before) Rainfall Event Inspectio~ (After) RainFall Inches 29 ~ ~ r ' , , ' ~ , ~ ~ ~ ~ ~ r Construction General Permit Inspection Checklist [] Regular Inspection [) Rainfall Event Inspection (Before) [ ] Rainfall Event Inspection (ARer) Rainfall Inspected By: Project: Date: Inches YES NO Location Are the BMPs called for on the SWPPP installed in the proper location and according to the specifications for the SWPPP? Are all operational storm drain inlets protected from sediment inflow? Do any structural practices requue repair or c[ean-out to maintain adequate function? If yes, indicate which ones: Are construction on-site tra~c routes, parking, and storage of equipment and supplies restricted to areas specifically designated for those uses? Are locations of temporary soil stock piles or construction materials in approved azeas? Do any seeded or landscaped areas require maintenance, irrigation, fertilization, seeding, or mulching? Is there any evidence that sediment is leaving the site? Is there silt buildup in downstream storm drains? Is there any evidence of erosion (i.e., rills and gullies) on cut or fill slopes? Is there any evidence of sediment, debris, or mud on public roads at intersections with site access roads? Is there any evidence of non-visible pollutants (oil, grease, fuel, etc.) or debris (construction materials or wastes) entering the storm drain system? If yes, explain. Does the SWPPP require revisions? If yes, explain: ~~~ ~ 30 Construction General Permit Inspection Checklist [] Regulaz Inspection [] Rainfall Event Inspection (Before) [] Rainfall Event Inspection (After) Rainfall Inches Inspected By: Project: Date: YES NO Location Are the BMPs called for on the SWPPP installed in the proper ]ocation and according to the specifications for the SWPPP? Are all operational storm drain inlets protected from sediment inflow? Do any structural practices require repair or clean-out to maintain adequate function? If yes, indicate which ones: Are construction on-site tra~c routes, parking, and storage of equipment and supplies restricted to areas specifically designated for those uses? Are locations of temporary soil stock piles or construction materials in approved areas? Do any seeded or landscaped areas require maintenance, inigation, fertilization, seeding, or mulching? Is there any. evidence that sediment is leaving the site? Is there silt buildup in downstream storm drains? Is there any evidence of erosion (i.e., rills and gullies) on cut or fill slopes? Is there any evidence of sediment, debris, or mud on public roads at intersections with site access roads? Is there any evidence of non-visible pollutants (oil, grease, fuel, etc.) or debris (construction materials or wastes) entering the storm drain system? If yes, explain. Does the SWPPP requue revisions? If yes, explain: 2'~ 31 Construction General Permit Inspection Checklist I t' ~ ' ~ , ' ~ ~ ~ ' r ~ ~ [] Regular Inspection (] Rainfall Event Inspection (Before) [] Rainfall Event Inspection (After) Rainfal] Inches Inspected By: (Name and Signahire) Project: Date: YES NO Location Are the BMPs called for on the SWPPP installed in the proper location and according to the specifications for the SWPPP? Are all operational storm drain inlets protected from sediment inflow? Do any structural practices require repair or clean-out to maintai~ adequate function? If yes, indicate which ones: Are construction on-site traffic routes, parking, and storage of equipment and supplies restricted to areas specif3cally designated for those uses? Are locations of temporary soil stock piles or construction materials in approved areas? Do any seeded or tandscaped areas require maintenance, irrigation, fertilization, seeding, or mulching? Is there any evidence that sediment is leaving the site? Is there silt buildup in downstream storm drains? Is there any evidence of erosion (i.e, rills and gullies) on cut or fill slopes? Is there any evidence of sediment, debris, or mud on public roads at intersections with site access roads7 Is there any evidence of non-visible pollutants (oil, grease, fuel, etc.) or debris (construction materials or wastes) entering the storm drain system? If yes, explain. Does the SWPPP require revisions? If yes, explain: 32 ~ ~' ~ , ' 1 ~ ' r r r ~ ~ r ~ ~ ~ ~ ~ ~ Test Sample Log Company Name: Project Name: Project Locatio Sample No. Sample Location Date and Time Sample Collected Sample Method Preservation Method Custody Transfer Date and Time Notes Sample No. is assigned for tracking purposes. Use number to identify specific test sample in all test sample records. Samp[e Location is based on SWPPP Site Plan, which shows location of sampling sites. Chain of Custody Log below should be completed by both parties at time of transfer of test sample. Chain of Custody Log Company Name: Sample Na Sample Date and Time Preservation Method Relinquished by: Relinquis6ed to: Date and Time Notes ~ 33 i ' 1 '! i ' ~ i ,I 'I i '! ,' ,~ ,i ~ ~ ~ ' r , ~ ~ ~ ~ ~ ' Test Sample Log Company Name: _ Project Name: Project Location: Sample No. ~ Sample Location Date and Time Sample Collected Sample Method Preservation Method Custody Transfer Date and Time Notes Sample No. is assigned for tracking purposes. Use number to identify specific test sample in all test sample records. Sample Location is based on SWPPP Site Plan, which shows location of sampling sites. Chain of Custody Log below should be completed by both parties at time of transfer of test sample. Chain of Custody Log Company Name: Sample Na Sample Date and Time Preservarion Method Relinquished by: Relinquished to: Date and Time Notes ~ v\ 34 Test Sample Log Company Name: _ Project Name: Project Location: Sample No. Sample Location Date and Time Sample Collected Sample Method Preservation Method Custody Transfer Date and Time Notes ; Sample No. is. assigned for tracking purposes. Use number to identify specific test sample in all test sample records. Snmple Location is based on S WPPP Site Plan, which shows location of sampling sites. ; Chain of Custody Log below should be completed by both parties at time of Vansfer of test sample. r , ' ' ~ ~ ' Chain of Custody Log Company Name: Sample No. Sample Date and Tiroe Preservation Method Relinquished by: Relinquished to: Date and Time Notes ' 35 ?~~' i '' 1~ '', ~! ~ ~ ( '~ ~ ~ Test Sample Log Company Name: Project Name: Project Locatio Sample No Sample Location Date and Time Sample Coltected Sample Met6od Preservation Method Custody Transfer Date and Time Notes ' Sample No. is assigned for tracking purposes. Use number to identify specific test sample in all test sample records. Sample Location is based on SWPPP Site Plan, which shows location of sampling sites. Chain of Custody Lng below should be compieted by both parties at time of transfer of test sample. ~ ' ~ Chain of Custody Log ' , ~ r r ~ , ~~ ~~ Company Name: Sample No. Sample Date and ,r~me Preservation Method Relinquished by: Relinqui5hed to: Date and Time Notes 36 2°`3 1~ i 1! Test Sample Log Company Name: _ 'i P roject Name: ~ Project Location: ~ ~ ~~ ~ ~ Sample No. Sample Location Date and Time Sample Collected Sample Method Preservation Method Custody Transfer Date and Time Notes ~ Sample No. is assigned for tracking purposes. Use numlier to identify specific test sample in all test sample records. SampleLocation is based on SWPPP Site Plan, which shows location of sampling sites. ' Chain of Custody Log below should be completed by both parties at time of transfer of test sample. Chain of Custody Log ' r r r r, ~ Company Name: Sample No. Sample Date and Time Preservation Method Relinquished by: Relinquished to: Date and Time Notes ~i 3~ ~ ~ ~~ ~ ~ 0 ~ ~ r L~~ ~ r r ~ ~ ~ APPENDIX A BMP DETAILS 2°~ ~~ i r ' ' ' , ~ r , ' ' ' , ~ r ~ ~ ' , BMP: TEMPORARYSTREAMCROSSING Objectives ~ ~ • Housekeeping PracGce ~ . ~,; ~ ' ~ ~ ~, ~• Contain Waste ... ~_ ~ ~ i µ• ,.i: ~ inimizeDistur6edArea Y ~ ;,,: :'.'..'::.' .~ ~\ '1 v . ~~~ '~'~`"~'" ' bili Di d .. ......;. •.~\ .....: a ze sturbe Are ~ . .• +. ~, ,i.; ~ ~ ~~ ~~•. ~~: %? f •, " ~ rotect Slopes/Channe \~ '~'~. ' C l Si ` •i ~/ , 4i ontro te Penmeter ~` Y ~' ~~ Controllntemal Erosion GENERAL DFSCRIPI'ION Targeted Pallutants A temporary access sveam crossing is a temporary culvert, ford or bridge placed aQOSS a ~ Sediment watcrway to provide access for conswction purposes for a period of less than one yeaz. ~ Nutrients Temporary access crossings aze not intended to be used [o maintain traffic for the general pubGc. ~ Toxic Materials Q Oil & Grease SUITABLE APPLICATIONS Q Floatab/e Maferials Temporary stream crossings should be installed at all designated crossings of perennial C ~ Olh t ti and intemtittent sveams on the constcuction site, as well as for dry channels whic6 may be er ons ruc on signiFicandy eroded by construction traffic. Weste IIVSTALLATION/APPLICATION CRITERIA ~ (1kaly to Have Requires la~owledge of sveam flows and soil svength and should be designed under the Slgnitlcant Impact b bl C ~ P d'uecaon ~of a Califomia re istered en meer wit6 laiowled e of bo~ h drau6cs and 8 8~ g Y ro a e ow or Unknownlmpact conswcdon loading requiremen~s for swcaues . Implementation RE UIREMENTS Q P.equirements Maintenance - Inspect weekly and after each significan[ rainfall, including assessmen[ of 0 Capita/ Costs foundations. Q O&M Costs - Periodically remove silt from aossings. 0 Maintenance - Replace lost aggregate from inlets and ouUeCs oF culverts. Q T i i Cost ra n ng - CalTrans Conswction Cost Index for temporary bddge crossing is $45-595 per ~ Suitability for squaze feet Slopes>5'S: LIMITATIONS May be an expensive for a tempocary improvement Requices other BMPs to minimize soil disturbance during installation and removal. Fords should only be used in dry weather. ~ High 0 Low ESC22 Best Managemen Prectices Construction Aandbook 5-30 March,l993 2~,~ 1 ~~ ,' '! ~ tl '~ ~ '! ~ ~ r r r r r r ~ ~ Additional Information - Temporary Stream Crossing A temporary access sveam crossing is a culvert, ford, or bridge placed across a waterway to provide access for conswc- tion for a penod of less than one year. Temporary access crossings aze not intended to be used for general pubtic vafCic. "Ibe purpose of ~his BMP is to provide a safe, erosion-Cree access across a sveam for construction equipment Minimum standards and specificauons for the design, conswcuon, maintenance, and removal of the structure shouid be established by an engineer regis~ered in CaliFomia Temporary sveam crossings may be necessary ro preven[ conswcdon equip- ment from causing erosion of the sveam and tracking sediment and other pollutants inm the stream. Temporary sveam crossings are used as access poinrs to conswcaon sites when o~er detour rou~es may be too long or burdensome for the conswction equipmenc Often heavy construcdon equipment must cross streams or cree~and detour routes may impose too many constraints such as being too nazrow or poor sofl svengtti for the equipment load- ings. Additionaily, the contractor may find a temporary stream crossing more economical for light-dury vehicles to use for frequent aossings, and may have less environmental impact than conswcaon of a temporary access road. Inctalla~on/Apnli a ion Temporary access stream crossings should be sized and installed according tn the diainage design criteria of We local municipality. Design criteria s6ould be based on standard engineering pracuces for culvert design with provisions for minimizing impacts on diswrbed crossing azeas. TLree types of tempotary access stream crossings may be considered: Temrxir rv A ss ~Iv rt~ A temporary access culvert is effecdve in convoDing erosion but will cause erosion during installation and removal. A[emporary culvert can be easily constructed and allows for heavy equipment loads. Tem[tc~rarv Accet~ Ford- A tempotary access ford provides little sediment and erosion conVOl and is ineffective in controlling erosion in the svearn channel. A temporary ford is tbe least expensive stream aossing and allows fo~ maximum load limits. It also offers very low maintenance. Fords are more appropriate during the dry season and in arid areas of Califomia ~• Witb the appropriace materials and designs, a temporary access bridge causes the least erosion of the stream channel crossing during its installation and removai. During the long summer conswction season in California, rainfall is infrequen[ and many streams are dry. Undu these conditions, a tempoiary access ford may be sufficienG A ford is not appropriate if conswction will continue Wrough the winter rainy season, if summer thunderstorms are tikely, or if the stream tlows during most of the year.1'emporary access culvens and bridges should [ben be considered and, if used, s6ould be sized [o pass a significant design storm (i.e., az least a lQyeaz storm).1'he temporery stream crossing should be protected against erosion, both ro ptevent excessive sedimentation in the stream and to preven[ was6out of t6e crossing (and, consequendy, cosdy conswction delays). Spe~a~re must be taken when crossing an environmentally sensitive watenvay. Oils or other poten[ially 6azardous materials shall not be used for surface trea~ents. Street nmoff should na be allowed to spill down crossing sideslopes. Conswction in watercourses should be at or near the naturel elevation of the sveam bed to prevent any potential flooding upstream of tbe crossing. In addiuon, [!ie following liuutauons may apply: I ESC22 I ~ Construction Handbook 5- 31 March, ]993 ~~ ~ ' , ' ' II Additional Information - remporary stream cross~~9 • May be ezpensive temporary cost • Increased soil disturbance upon installation and removal • Temporary culverrs need regular maintenance and can cause erosion if the wlvert becomes clogged. • A temporary ford offers Gttle if any erosion control in flowing streams and c.an often make erosion wocx. Fords should only be used in tbe dry season on dry streams. Consirucdon in watenvays is subjec[ w addidonal pecmit requirements. Contact the local municipal storm water agenty for additional information. ~ , ~ ~ t ' ~ ~ ~ ~ ~ ~ REFERENCES Bank and Shore Praecaon, CalTrans - November 1970. Best htanagement Practices and Frosion Convol Manual for Consvuction Sites, Flood Control District of Maricopa Coimty, Arizona, September, 1992, ~ ESC22 I ~ Construction Handbook 5-32 March, 1993 2~~' i ~ 'I I ; ~! ~ ~ ~ 1 1 1 1 , ~ ' ' , , ~ , , ~ 1 Additional information - Tempo~ary sUeam cross~n9 ~ ~- ~ = ~~' e ~ ~h ~~_ = .:~ ~/ (~~,~ , ~ /~ ~~ ~; ~ ~~:: ~~ ~ ~,~`~d ~ ~ / - t.y- SURFACE FLOW i ~ OIVERTED BY S' ~ _ ~~~ -.~ _ ~. . ~~ ~ , = ~~ ~~~ - l = ~~ ~ : _ ~-. ~ ~' f ~ ~ ,~ AGGREGATE BED OYE ~ ~_ FILiER CLOTH AOGREGATE APPROACH 5~ I MAXIMUM. SLOPE ON ROAD SURFACE F~OW OIVERTE~ BY SWALE WATER LEVEL ~~~ ~• SURFACE FLOW DIVERTED~ BY SWALE ucw ROAD ~ AGGREGATE-~ ` - - J ~ORIG~NAL STREAM BED FILTER CLOTH TEMPORARY ACC SS FnRn Construction Handbook 5-34 ~ ESC22 1 March, 1993 2Qa ~ , '~ ~ ' ~ ~ ~ ~ ' ~ r r ~ ~ ~ BMP: CONSTRUCTION ROAD STABILIZATION objectives ousekeeping Practic Contain Waste inimize Distur6ed Are tabilize Disturbed Area rotectSlopes/Channe Control Site Perimeter Control lnternal Erosion GENERAL DFSCRIPTION Targeted Pollutants Accessroads,subdivisionroads,parkingare~s,andotheron-sitevehiclevansportationroutes ~ S di should be stabilized immedia[ely after grading and frequently maintained to prevent erosion e ment and convol dusL ~ Nutrients 0 Toxic Materia/s SUTfABLE APPLICATIONS Q Oi!& G • Temporary conswction vaffic. rease • Pbased conswction projects and off-site mad access. Q Floatable Materials • ~~p~ ro~. ~ Other Construction • Conetxucuon during wet weather. Waste INSTALLATION/APPLICATION CRI1'ERIA • Road should follow topographic contours to reduce erosion of the roadway. • 'ILe roadway slope should not exceed 15 percent • Gravel roads should be a minimum 4-inch tbick, 2-3 inch coarse aggregate base applied immediately after grading, or as recommended by soils engineer. • Chemical stabilizers or watu are usually required on gravei a dirt roads to prevent dus[ (see Dust Convol ESC 21). REQUIREMENTS • Maintenance - Periodically apply additional aggregate on gravel roads. - Active dirt conswction roads aze commonly watered th~ee or more times per day during the dry season. - Inspect weekly, and after each rain. - Repair any eroded areas immediately. • Cost - Gravel construction roads aze moderately expensive, but cost is often balanced by reducaons ia conswction delay. - No addiuonal costs for dust control on conswc6on roads should be required above that needed [o meet local ait quality requirements. LIMTTATIONS • 'Ibe roadway must be removed a paved when conswction is complete. • Certain chemical stabiliaation methods may cause storm water or soil polludon and should not be used (see Dust Control ESC 21). • Managemen[ of conswcaon traf6c is subject to air quality control measures. Contact t6e local air quality management agency. ~ Llkely fo Have SlgnlRcantlmpaef Q Probab/e Low or Unknownlmpact implementation Requirements Q Capital Costs Q O&M Costs Q Maintenance Q Training Q Suitability lor Slopes>SY. ' I ~ High ~ Law ~~ ESC23 Best Managemen Prectices 'i Construction Handbook 5• 35 March, 1993 (r- ~ ~' ~ Additional Information - Construction Road Stabifization ~~ Areas which are graded for conswction vehicle transport and parking purposes are especially susceptible to erosion and , dust T'he exposed soil sudace is conunually disturbed leaving no opporcunity for vegetadve stabiliTauoa Such areas i also tend to collect and nansport runoff waters along the"v surfaces. During wet weather, they often becpme muddy ' quagmires which generate signitcant quanuties of sediment that may potiute nearby streams or be vansponed off-site on ~he wheels of constiucuon vehicles. Dirt roads can become so unstablC during wet weather that they are vinually ' unusable. '' ECficient conswcuon road stabilizauon not only reduces on-site erosion but can significan0y speed on-si[e work, avoid '{ instances of immobilized machinery and delivery vehicles, and generally improve site efficiency and wor4:ing conditions ' during adverse weather. ~ . . . . . '~ Where feasible, atrerr~auve routcs should be made for conswction traffic; one for use in dry condiuon, [he other for wet conditions which incorporate tl~e meazures lisred for Uiis BMP. Pecmanent roads and h ~ as possible after grading. As an alternarive where conswcdon wi11 be A ~~g ar~ should be paved as sop~ ' I stabilization may so~ve poren[ial erosion and stabiGt roblems. Tem rP ~~e early applicauon of gravel or chemical ~ ~~Y ~ason and/or on slopes greater tban 5 y P ~O ~ g~~el madway should be considered during ihe percenc When gravel road is needed, apply a minimum 4-inch coursa of 2 tp 4~nch crushed rock, gravc~ base, or crushed surfacing ', basecourseimmediate~y~'~rgradingorthecompletionofuuliryinstallauonwithintherig6t-of-way.ChemicalstabiG~ation may aLso be used upon compacted native sub-grade (see the Dust Convol BMP ESC 21). Thesc chemica! convols should ' i be applied per the manufacturer's directions. i Temporary roads s6ould follow [he concour of the natural te7rain to the maxiuium extent possible. Slope should not exceed IS percent Roadways should be carefullygraded to drain transversely, Provide drain9ge swales on each side of theroadway in the case of a crowned section, or one side in the case of super=elevated section. Simple gravel berms without a trench can ~~ also be used. ~ I Installed inlets s6ould be protected to preventsediment-laden water Crom entering the stotm sewer system (see "S[orm Drain Intet Protecuon" ESC 54). REFERENCES ! Best Management Pracuces and Fiosion Control Manual for Construcuon Sitcs, Flood Control Disuict of Maricopa '~ Counry, Arizona, September1992. ' Maziual of Standards of Erosion and Sediment Controi Measures, Associaaon of Bay Area Govemmenrs, June1981. ~ S[ormwater Management Warrs for tl~e Puget Sound Basin, Washington State Departmen[ of Ecology, T'he Technical ~ Manual - Feb~uary 1992,.PubGcadon # 91-75. Vitginia Erosion and Sedimentation Control Handbook, V'uginia Depar~ent of Conservauon and Recreadon, Division ~ of Soil and Water Conservation, 1991. Water Quaiity Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Tahce Regional Ptanning Agency - November 1988. ~ ~ I ESC23 1 '~ Construction Randbook 5 - 36 ~ t March, 1993 ~ 1~ ,M I~ BMP: STABILIZED CONSTRUCTION ENTRANCE '1 ~ ' LJ ~ r ~ 0 ' GENERAL DFSCRIPTION TLe consauction enttance practice is a stabilized pad of aggtegaze underlain with filter cloth located az any poin[ where traffic will be entering or leaving a constmction site to or fmm a public right-of-way, street, alley, sidewalk or parking area. Stahalizing tha conswction entrance signiFicantly reduces the amount of setliment (dus4 mud) hacked off-site, especially if a wash~ack incmporated for removing caked on sediment. SUTTABI,E pppLICATIONS • All points of construction ingress and egress. • Unpaved azeas where sediment hacking occucs from site onto paved roads. INSTALLATIONlAPPLICATION CRITERIp • Construct on level gro~md wherc possible. • Stoces s6ould be 1-3 inches. • Minimum depth of s[ones should be 6 inches or as recommended by soils engineer, • Length should be Safoot minimum, atid 30.foot minimum width, • Arovide ample nuning radii as part of enhancc. REQU7REMENTS • Maintenance - Inspec[ monthly and aRer each rainfall. ga - Replace g~avel material wheu surface wids are visible. - Remove all sediment deposited on paved roadways witLin 24 houts. - Remove gavel and filter fabric at comple6oo of construction • Cost Avcage annual cost for installation and maintenance (Source: Epq, 1992) - Without Wash Rock: $1500 each. - With Wash Rock: 52200 eac6. LIMTTATIONS • Requues periodic top dressing with additional srones. • Should be used in conjimcdon with street sweeping on adjaceat public rightof-way. Objectives ousekeaping Practice Contain Waste Disturbed Protect Slopes/Channels ntrol Site Perimet Control lntema/ Erosion Targeted Pollutants Q Sediment Q Nutrienta Q Toxic Materia/s Q Oil3 Grease ~ Fhatsb/e Mate~ia/s 0 Other Construcfion Watte ~ Uks/y W Havs . SJpn/Reant/mpset Q ProbabMLowor Unknown /mpact Implementation Requirements Q Capital Catts Q OSM Coata ~ Maintenance 0 Treining Q Suitability /or Sbpea>5`K ~ High Q Low ESC24 ~St Managemen Practices ~ Construction Handbook 5• 37 March, 1993 ~ ~ ~ Additional Information - Stabilized Construction Entrance ~ A stabilized conswction enuance is a pad of aggregate underlain with filter cioth located at any poin~ Wheie uaffic will ' be entering or leaving a cons Wction site to or from a public right-of-way, street, alley, sidewalk or parking area. The Qurpose of a stabilized constxuction entrance is to ~educe or eliminaze ihe vacking of sediment onro pubGc rights-of-way or streets. Reducing treckout of sedimenrs and other pollu[anrs onto paved roads helps prevem deposition of sedimenrs ; into locai storm dcains and producuon of airbome dust. Where treffic will be entering a leaving, a stabilized conswcuon enuance should be used at ail poincs of consaucdon ; ingress and egess. NPDES pe~its requ'ue tbat appropriaze measures be implemented to ptevent vxkout of sediments onto paved roadways, which is a significant soucce of sediments derived from mud and dirt cazryout from the unpaved roads and const:uction sites. ; Stabilized consWCtion entrances are modecately efFective in removing sediment from equipment leaving a conswction. s~re• The enaance should be build on t6e level groimd. Advantages of tLe Stabilized Conswction Ennance is tl~at it does remove some sediment hom equipment and scrves to channel conshuction traffic in and out of the sitc at specified ; ~oca[ions. Efficiency is greatly increated when a washing rnc1; is included as part of a stabilized conswction entrance. TLe aggregate for a stabilized conswcdon envance aprons s6ould be I to 3 inches in size, washed, well-greded gravel or ~ cYUSl~ed rock. Minimum apron dimensia~s of 30 f~ x 50 ft and 6 inches deep is adeyuate for two-way ingress/egress tcaffic. 7Le ena~ance must be properly graded to prevent runoff from leaving the constxuction site. ; W6en wash areas are provided, washing is done on a reinforced conaete pad (if'significant wat6ing is cecessary) or in an area stabilized with cnuhed stone which dcains inro a pmperly cpnstn~cted sediment trap or basin (FSC 55 and 56). Sediment barrie~ are provided to prevent sediments hom entering inro the stormwater sewer system, ditch, or waterway. ~ ~Con~,sWtt on level ground, S[abilized consWCtion enaances are rdther expensive [o constrvct and when a wash iaclc is inc[uded, a sediment trap of some kind must also be provided ro collect wash water mnoff. 1' Requues periodic top dressing with additional stoces. • Should be used in conjimction with sprect sweeping on adjacent public rightof-way. ~ REFERENCES Best Management Practices and Frosion Control Manual for Consm~cdon Sifes, Fipod Control District of Maricopa ~ Co~mty. Arizona. September 1992. Manual of Standards of Ecbsion and 5ediment Control Measures, Assoc~a~ion of Bay Area Govecnmenrs, ~ June 1981. Proposed Guidance Specifying Management Measutes for Sources of Nonpoint Polludon in Coastal Wate~s, Work Group Working Paper, USEPA, April, 1992. ~ Stormwatcr Managemrnt Water for the Puget Sound Basiu, Wachingtnn State Dep,a~ent of Ecology,lbe TecLnical Mannat - Febtuary 1992, Publication # 91-75. ~ V'uginia Erosion and Sedimentation ConWl Handbook, V'uginia De~armient of Conxrvazion and Recreadon, Division of Soil and Water Conservaaon, 1991. ~ Wa~er Quality Management Plan for tbe Lake Tahce Region, Volume II, Hanclbook of Management ESC24 Practices, Tahce Regional Planning Agency - November 1988. e..~ ~ Rtlloti ; Construction Handbook 5 - 38 March, 1993 .~~ ~: ~, !r , ~ ~ ~ ~ ~ ~ ' ' r ~ r i ~ ~ ~ 1 ~ , ' ' ~ Additional Information - Stabilized Construction Entrance / , ~ • / - ~~~/ ~ ~ ~~ ~ ~ ~ `~ /~ ~ VEHCLE LENGTH DITCH 70 CARRY WASH WATER TO SEDIMENT BASIN OR TRAP WASH RACK . ,.' , ` .. Q a . ~ . "_~_ I , ~DRAIN SPACE ~ REINFORCED CONCRETE CHANNEL/DITCH BOTTOM WASH RAGK (SCFIEMATIC) ~ R20' '`. METAL BAR . FILTER FABRIC--~ / ~ 1" TO 3" COARSE -~ Z AGGREGATE ~ io ST R D ONSTRUGTiON hTRAW^~ 1 ESC24 1 Construction Handbook 5• 39 Dlarch, 1993 !i' i '~ ~1 I '' ,i ,i 1~ ,~ i '~ ~ ~ ~ a ' r ~ , r ~ i , BMP: EARTH DIKE objectives Nousekeeping Prac6ces Contain Wast • - Minimize Disturbed Areas _ ~ Stabilize Disturbed Areas rotectSlopes/Channe ~ - ontrol Site Perimete ontrol lntemal Erosio GENERAL DFSCRIP'TION Targeted Pollutants 'I'hetemporaryearthdikeisatemporarybeimorridgeofcompactedsoil,usedtodivertrunoff ~ S di or cLannel water [o a des'ved locaflon. e ment Q Nutrients SUTTABLE APPLICATIONS Q Toxic Materials Earth dikes are typically used w divert concentrated runoff tLrough disturbed azeas into Q Oil & G another BMP (e.g., sediment baSins), to diven runoff away from disturbed or unstable slopes, rease to diveR runoff Crom of6si[e and undisturbed areas around disturbed areas, and as a ~ Floatabfe Materials containment forconswcuon materials and wastes. 7'he dikes should remain in place unul ihe 0 Othe~ Construction diswrbed areas are permanently stabilized.'I'he dikes mus[ be on-site and must safely convey Waste anticipated Oood flows. ~ ~ Uke/y to Have INSTALLATION/APPLICATION CRITERIA S1gnlilcant ~mpact All dikes should be compacted by earth-moving equipmen~ ~ Probab/e (.ow or All dikes should have ositive draina e to t bili A l Unknown ~mpect p g a s a ze out eG Top width may be wider and side slopes may be [latter az aossings for construcdon Implementation ~~'~' ` Dikes should ditect sediment-laden runoff into a sediment vapping device, Requirements Dikes should be stabilized wiih vegetation, chemicals, or physical devices. Q Capita/ Casts REQUIREMENTS ~ O&M Costs • Main[enance 0 Maintenance Inspect periodically and after every significant reinfall; repair as necessary. ~ Training • Cos[ Q Suita6iliry for - Costrangesfrom$iStoS55perfootforbothearthworkandstabilizationanddepends Slopes>59'. on availability of mazerial, site location, and access. LIMTTATIONS Dikes s6ould not be used for drainage azeas greater tban 10 aczes, or along slopes greater tLan IOpercent Forlargerareasmorepermanrntdcainageswcturesshouldbebuil~ Alldrainage swctures should be built in compliance with toca! municipal requiremen~s. ~ High 0 Low Earth dikes may aeate more disaubed azea on site and become barriers to conswction i C C r Q O ~ equ pment. V V V Fanh dik s m t b bili d i e us e sta ze mmediately, which adds cost and maintenance concems, Diverted storm water may cause downsveam t]opd damage. • Dikes should not be conswcted of soils which may be euily eroded. • Regrading tLe site to remove the dil:e may add addiuonal cos~ Best ' Managemen Practices Construction Handbook 5-40 March, 1993 • ~ ' , ' ' r ' ' , ~ ' t , ~ ~ ~ ~ ~ Additional Information - Earth Dike 'Ibe temporary earth dike is a berm orridge of compacted soil, located in suc6 a manneras ro diverts[ocm waterto a sediment trapping device or stabilized ouUe4 ~~eby reducing the potenaal forerosion and offsite sedimentation. Earth dikes can a]so be used to divert:unofF from off-site and from undisturbed azeas away from disaubed areac, and to diven sheet flows away from unprotected slopes. An eanh dike dces not itself control erosion or remove sediment from runoff; a dike prevents erosion by d'uecting runoff to an erosion control device such as a sediment trap or d'vec[ing runoff away from an erodible a~ea Temporary diversion dikes should not adverscly impact adjacent properties and must confmm to local tloodplain managemen[ regularions, and should not be used in azeas with slopes steeper tLan 10%. • TLe advantages of the temporery eartL dike include the ability to handle flows from large drainage areas. • Oncesrabilized,eazthdikesrequirerelatively6[demaintenance. Additionally,theearthdikesazeretativelyinexpensive to install since [he soil material required for conswcrion may be available on-site, and can be conswcted as part of the initial grading operdtions, while the equipment is on-site. • Uses on-site materials. installation/AQpli ation .ri[ ria Temporaryearthdikesareapiactical,inexpensiveBMPusedtodivertstormwaternmoff. Temporarydiversiondikesshould be installed in ~he following manner: 1. All dikes should be compacted by earth-moving equipmenL 2 All dikes should have posidve drainage to an oude~ 3. All dikes should haye 2:1 side siopes, 18 inches minimum height, and a minimum top width of 24 inches. Top widt6 may be wider and side slopes may be t7atter az crossings for consUUCtion vafFic. 4. The oudet from the earth dike must function with a minimum of erosion. R~moff should be conveyed [o a sediment tmpping device such as a sediment trap (ESC 55) or sediment buin (ESC S~when either the dike channel or the drainage aiea above the dike arc not adequately stabilized. 5. Temporary stabilization may be achieved using seed and mulching for slopes less than 5°l0, and either rip-rap or sod for slopes in excess of 5%. In eitLer c~se, stabiliaadon of the earth dike should be completed immedia[ely afterconsaucdon or prior to the fi~[ rain. 6. If riprap is used to stabilize the channel formed along the tce of the dike, the following typical speciticabons apply: CHANNEL RIPRAP 'RAn - CTAA~ON 0.5-1.OY6 4" Rock 1.1-2.046 6" Rock 2.1~.09b 8"Rock 4.1-5.0~ 8-12" Riprap 7. TLe stone riprap, recycled conaete, etc. used for stabilization should be pressed into the soil witb construction equipmenL 8. Filter cloth may be used [o cover dikes in use for long periods. 9. Construction activiry on the eacth dike should be kept to a minimum. REFERENCES Best Management Prac6ces and Frosion Convol Manual for Construcdon Sites, F7ood Convol District of Maricopa Coimty, Arizona, September 1992. "Ihaft - Sedimentation and Frosion Control, An Inveotory of Current Pracdces", U.S.E.P.A., April, 1990. I ESC30 1 ~ Construction Handbook ' S• 41 March, 1993 ~ i '~ 'I ~ '~ + ~ , ,I ,I ,f ~+ ~ r ~ r i ~r , ~ ~ Construction Handbook 5-42 Mareh, 1993 • l/'"~ , '~ '' ~~ ~ ~' ~' '~ ' ' 'i 'I ~ ' '~ 'S t~ 'i ~~ ~1 ; '+ I '' Additional Information - Eartn ~~ke B COMPACTED FILL 2 : 1 SLOPE OR FLATTER. ~~'~~ ~ I~I I I- a ~~~ R~ - BOTH SIDES I I~ I~ I I- ~ I~~ I I_\ o ' GRA~E LINE I CTI- ~~ I I~ ~ I~I~IC ~~~~L\ ~~ ~\~~\\~~`~ ~~~~~ ~ -~ II~I~II~:'- -- - ~ = •- c „~ ~y\/\~j\~j\~\/ ~~~ ~ ~~~~\~~~\~~~ ~~~ ~/~~~~ . R U ~ SLOPES EX AVATE TO PRO VIOE RE~URED FIOW WIDTH AT FLOW DEPTH REQUIREMENTS BASED ON UPSTREAM DRAINAGE AREA ~IKE 1 DIKE 2 (5 ACRES OR LESS) (5-10 ACRES) A-~IKE HEIGHT 18" 36" B-DIKE WIDTH 24" 36" C-F~OW WI~TH 4' 6' D-FLOW DEPTH 8" 15" TEMPORARY DIVERSION DIKE ESqO Construction Handbook 5-43 March, 1993 ~ 1i, ~' I ' ~ ~ 11 ~ ~ ' ' r r ~ ~ , ~ BMP: TEMPORARY DRAINS AND SWALES objectives Housekeepinq Practices . . Contain Waste . ' Minrmize Distur6ed Areas . Stabilize Disturbed Areas rotectSlopes/Channe - Control Site Perimete ontrof Internal Erosio GENERAL DESCRIPTION Targeted Pollutants Temporuy Mdins and swales aze used to divert off-site runoff around the construction site, ~ Sediment divert runof[ from stabilized areas around dismrbed areas, and direct runoff into sediment basins or traps. ~ Nutrients . ~ Toxie Materials SUTTABLE APPLICATIONS Q Oil 6 Grease Temporary dcains and swales are appropriate for diverting any ~pslope runofF around unstabIIized or diswrbed areas of ihe conswcaon site: ~ Floatabfe Materials Prevent slope failutes. Q Other Construction Prevent damage to adjacent property. Waste Prevents erosion and transport of sediments into water ways. IncTeases We po[ential for infiltration. ~ Ukety to Have Diveru sediment-laden runoff into sediment basins or traps. srgn;ncanr Impact ~ ~ Q ProbableLowor INSTALLATION/APPLICATION CRITERIA Unknown Impact Temporarydcainageswaleswilleffecrivelyconveyrunoffandavoiderosionifbuiltproperly: ~mplementation Size cemporary dcainage swales using local drainage design criteria Requirements A permanen[ drainage channet must be designed by a professiona] engineer (see the local drainage design crneria for proper design). Q Capital Costs At a minimum, rbe drain/swale should confom~ to predevelopment drainage pattems Q O&M Costs and capacities. Cotuwct Ihe drain/swale with an unintertupted, posiqve grade to a stabilized ouUeL ~ Mainrenance Provide erosion protecdon or energy dissipation measures if the flow out of the drain ~ Training or swale can reach an erosive velocity. Q Suitabilify for S/opes ~5Y REQUIREMENTS Maintenance - Inspec[ weekly and after each rain. - Repair any erosion immediately. - Remove sediment whic6 builds up in the swale and resuicts ics flow capaciry. • Cost ~ High ~ Low - The wst of a dcainage swale increases with drainage azea and slope. Typical. swales for controlling intemal emsion aze inexpensive. ~ e(~~ i V L/ 1 LIMITATION S Temporary drains and swales or any other diversion of runoff should not adversely impact upsrream or downsveam propenies. Temporary drains and swales must conform to local tloodplain management require- ments. Best Managemen Practices ~ Construction Handbook 5- 44 March, 1993 'L~ i ~; ~ , '~ ~ i , i ~ ~ ~ '' i '' ~ r r ~ ~ ~ r r ~ ~ ~ Additl0t131 It1fOC1118tI0t1- Temporary Drains and Swales ~3:1 OR FLATTER -~ . 18" (MIN.) ~-~ ~~-~~ .~~~ ~~~~ ~ ~~~ i~l i r~, ~i II~I~" I~~i ~ I'_ _I 2' (MIN.) STABILIZATION LEVEL ~ROSS SECTION O.Sx OR STEEPER. DEPENDENT ON TOPOGRAPHY STABLE OUTLET REQUIRE f~FLOW ~~FLOW PLAN TEMPORARY DRAINA~E SWALE E5q1 ~ q.Gb. Construction Handbook 5- 46 March, 1993 ~:. ~: ~ ~ ~~ ~ ~ ~ ' ~ ~ r ' , ~ r ~ ~ ~ ~ ~ r ~ ~ '~ Additionai Information - Temporary Drains and Swales ~I Slopes tha[ aze formed during cut and fill operaaons should be protected from erosion by runoff. A combination of a temporary drainage swale and an earth dike (see ESC30) at the top of a slope cac~ safely divert nmoff to a location where it can safely be brought to the bottom of tt~e slope (see Pipe Slope Drain ESC32). A combination dike and swale is easily conswcted by a single pass of a bulldozer or grader and compacted by a second pass of the tracks or wheels over the ridge. Diversion structures should be installed when the site is initially graded, and re¢tain in place imtil post-construcaon BMPs are installed and/or the slopes aze stabilized. Diversion prutices concentrate the volume of surface runoff, increasing its velocity and erosive force. 'Chus, the flow out of tLe drain orswale must be directedonto a stabilized azea or into a grade stabilization st:ucaue. A swale should be stabiliud using vegetation, chemical treaunen4 rcek rip-rap, matting, a other physical means of stabil'vation, if significan[ erosion will occur. Any drain or swale whic6 conveys sediment-laden cunoff must be diverted into a sediment basin or traQ before it is discharged from the site. Tns al a inn/Anplication rit ria DiversiondrainsorswalesareonlyeCfectiveif~eyareproperlyinstalled. SwalesaremoreefFecdvethandikesbequsethey tend to be more stable. The combinatlon of a swale with a dike on the downhill side is ~e most cost-effecdve divecsion. Standard engineering design criteria for small open cLannel and closed conveyance systems should be used (see the loca! dcainage design manual). Unless local dcainage design criteria state otherwise, drains or swales should be designed as follows: • No more tLan 5 xres may drain [o a temporary drain or swale • Place the drain or swale above, not on, a cut and fill slope • Swale bottom width should be at least 2 ft • Depth of the swale should be at least 18 inches • Side slopes should be 2:1 or tlazter • Drain or swale should be layed at a grade of at least 1 percen4 but not more than 15 peccent • 'Ibe swale must not be overtopped by tbe 10-year, 24Lour stocm, icrespective of tbe design criteria stated above • Remove all vees, stumps, obswctions, and other objectionable material from the swale when it is built • Compact any fill material along tLe path of the swate • Stabilize all swales immediatcly. Sced and mulch swales at a slope of less chan 5 percen4 and use rip-rap or sod for swales with a slope between 5 and I S percent • Do not operatc constiuction vehicles aaoss a swale uNess a stabilized aossing is provided. • 'ILe cost of swates and otLer diversion devices is generally included in the earthwork cos4 ~ a sepazate item under tLe grading budget of the project conswcfion contrecc. Best Management Pcacdces and Erosion Control Manual for Consmxtion Sires, Flood Control Disvict of Maricopa Coimty, Arizona, September 1992. "D~aft- Sedimentation and Erosion Control, An Inventory of Cuirent Prx6ces", U.SEP.A., April, 1990. Manual of Standards of Erosion and Sediment Control Measutes, Associadon of Bay Area Govemmencs, June 1981. Stotmwater Management Water for ~he Puget Sound Sasin, Washingtnn State Depaivnent of Ecology, T3e Technica! Manual - February 1992, Publication # 91-75. ESC31 Water Quality Management Plan for tl~e Lake Tahce Region, Volume II, Handbook of Management ~ Prectices, Tahoc Regional Planning Agency - November 1988. ~ Construction Handbook 5- 45 March, 1993 ~ , ; '' '~. I '' i '~ i ~ ~ ~ ,f ~ ~ r r r r r ~ BMP: SLOPE DRAIN Objectives Housekeeping Practices ~ Contain Waste Minimize Disturbed A~eas Sfabilize Distur6ed kreas ~ rotect Slopes/Channel Control Site Perimeter Control lnternal Erosion GENERAL DFSCRIP'CION Targeted Polluta~ts A temporary pipe or lined channel to drain the top of a slope to a stable disc6arge point az the ~ Sediment bouom of a slope wi~hout causing erosion. ~ Nutrients SUTTABI,E APPLICATIONS ~ Toxie Materials Where concentrated tlow of surface runoff must be conveyed down a slope in order to ~ Oi! & Grease prevenc erosion. Dcainage for top of slope diversion dikes or swales. ~ Floatable Materials Emergency spillway for a sediment basin. ~ Other Constructian Drainage for top of wdfill slopes where water can accumulate. Wasre The [ypes of slope drain can include: ~ Ukaly to Have Pipe drops. Slgn!/Ieant lmpaet Flexible dOwndrains. ~ Pro6abls Low or S ~ Unknown Impact ectionat downdrains. Lined terrnce drains. Implementation Requirements INSTALLATION/APPLICATION CRITERIA Secure inlet and surround with dikes to prevent gully erosion, and anchor pipe to 0 Capita! Cosfs slope. Q O&M Costs Size to convey at least the peak of a 10-year,lA-hour storm (See lxal flood control Q Maintenance agencyforrequirements). Q T i i • Stabilize oudet ra n ng Q Suitability for Q RE UIREMENTS Slopes>5Y. Maintenance - Swcture must be inspected regulazly and after storms. - Inlet must be frce of undercutting and no water should cucumvent tLe enuy. - Ou~et should not produce erosion; velociry dissipators must be mainrained. - Pipe anchors must be checked to ensure that the pipe remains anchored to the h 0 Low ~ Hi slope. g c~s~ - CalTrans Cost Sc6edule gives regional cost ranges. ESC32 LIMTTATIONS Maximum drainage area per slope dcain is 5 acres. (For lazge azeas use a paved chute, rock lined channel or addiuonal pipesJ Clogged stope drains will force water around the pipe and cause slope erosion. Dissipaaon of high flow velocities az the pipe outle[ is required to avoid downsveam gest emsion. Mana emen 9 • Failure can result in tloodine and severe erosion. PrdCtices Construction Handbook 5- 47 March, 1993 '~02 ~ ~ ~ ~ Additional Information - Slope Drain ~ '['be slope drain may be a rigid pipe, such as conugared metal, a tlexible condui4 or a lined terrace drain with the inlet placed on ihe top of a slope. The drain conveys concenvated runoff down to the bottom of the slope. The BMP typically is used in ~ combination with a diversion control, such as a temporary dike orswale, at the top of the slope, and serves as a temporary BMP [o reduce or eliminate slope erosion unul pertnanent BMPs are insralled and the slope is stabilized. ~ Thestopedrainisapplicableforanyconswcuonsitewhereconcenvatedsurfacerunoffcanaccumulateandmustbeconveyed down tLe slope in order to prevent erosion. The stope drain is effective because it prevents the stonnwa~er From flowing ti directlydowntheslopebyconfiningalltberunoCfin[oanenclosedpipeorchannel. Duerothetimelagbetweengradingslopes and installauon of permarient storm water cotluuon systems and slope stabiliTauon measures, temporary provisions to intercept runoff are sometimes necessary. Particularly in steep tetrain, slope drains can protect anstabiGzed areas from erosion. Typical uses include: ~ Emergency spillway for a sediment basin. Lhainage for top of cudfill slopes where storm water can accumula[e and must be conveyed down ihe slope. , Inctalla inn~An2ication rit ria Temporary slope drains are highly effective in eliminating slope erosion. Installation and maintenance requiremen ~s are small, especially when tlexible pipe is usecl. General criteria: r Gullyerosionisthemajorproblemwithslopedrains.Inletstructuresmustbesecurelyenvenchedandcompactedtoavoid severe gully erosion. Tbe drain must be securety anchored to the slope and mus[ be adequately sized to caRy the capaciry of che design stortn , and associated forces. The ouflet must be stabilized with rip-rap, concrete or other type of energy dissipator, or directed into a stable sediment ~ uap or basin. A debris rack is recommended at ~he inie4 and shouid be encouraged for larger pipes and at the oudet as a safery device to prevent small children from entering the pipe. Materials: Material selection and criteria for the pipe slope drain is often established by the local municipality. Soil type, rainfall • pacterns, conswcuon schedule, and available supply are some of We facrnrs to be considered. The followiog types of ~ slope drains are commonly used: ' B1Pld-PIDC~ ~is type of slope drain is also I~own as a pipe drop, 1'pe pipe usually consists of cociugated metai pipe ~ orrigid plastic pipe. TLe pipe is placed on undisturbed orcompacted soil and secured into the slope. One foot minimum cover is required on the pipe, and concrete thrust blocks must be used when required by tbe municipali[y or wairanted by t~e catculated thnist forces. Collars should be properly installed and secuced with metal sUappings or watertight collars. ~ • ~exible Pi~; qye f7exible pipe slope drain consists of a flexible conduit of 6eavy duty marerial. The conduit ma[erial is securely anchored into the slope and connections are watertigt~L 'I'Le conduit should be securely fastened to the metal inlet and outlet conduit sections with metal svappings or wazer tight collars. , ~ Secrionalp~~~~in~•'~e~ctionaldowndrainconsistsofpre-fabricated,sectionalconduitofhalf-ioundorth'vd-round material. The sectiona! downdrain performs similar to a IIume or chute. The pipe must be p~aced on undisturbed or compacted soil aqd secuted into the slope. • Concr t-1in d T rra Dnin• This is a concrete channel for draining water from a teirace on a slope to t6e next Ievel. , 'Ibese drains are after permenant structures which should be designed according to locai drainage design criteria ~ ESC32 r L ~~ '~>n<t~uction Handbook 5- 48 March, 1993 ~~~ ' iL l '~ ~ ~ ~ ' ~ r ~ ~ ' ~ ~ ~ ~ Additional Information - Slope Drain Design: Uniess specified by the local municipality, the capariry for temporary drains should be suff cient to handle the peak nmoff from a 10-year, 24hour rainfall event. The pipe size may be computed using the Rational Metbod or a method established by the local municipality. Higher flows must be safely staed or routed to prevent any offsite concentrabon of flow, and any erosion of We slope. ~ As a guide, temporary pipe slope drains should not be sized smaller than shown in tbe following table: MINIMUM MAXIMCJM PIPE DIAMETER DRAINAGE AREA (ACRES) 12" 0.5 18" 1.5 21" 2S 24" 3.5 30" 5.0 Peimanent improvements must be desigred and installed if the drainage azea is greater tLan S acres. 77~e following additional design criteria should be considered: Corutiua the pipe slope drain entrance of a standard flared end section with a minimum 6-inch metal tce piate to preven[ runoff from undercutting tlie pipe inlet. TLe slope of the entrance is usually az least 3 percent~ Thoroughly compact the soil around and under the pipe and envance section, Securely fasten the slope drain sections together, have gasketed wate:tig6t fittings, and securely anchored inro the soil. Secure t6e flazed inlet section to the slope drain and Lave watertight connecting bands. Use interceptor dikes rn direct runoff into a slope drain. 1be height of ~he dike shoutd be a[ least 1 foot higher at all points than the Wp of the inlet pipe. • If the pipe slope drain is conveying sedimen[-laden water, direct all flows intn a sediment vap (ESC55) ot sediment basin (ESCS~. Unless t6e pipe d'uectly enters a sediment trap/basin, stabilize the area below the ouilet with a riprap apron. [.imitation5 . Installafion is criacal for effecave usc of the pipe slope dcaiu ro minimize poten6al gu-ly erosion. Mazimum dtainage area per pipe slope drain is 5 acres. For larger areas use a paved chute, rock lined c6annel or addidonal pipes. (See the local municipality for drainage requicements) During large srorms, pipe slope dcains may become clogged or overcharged, forcing water around tbe pipe and causing extreme slope erosioa S Wc[ures for dissipation of high flow velocities az the pipe outlet must be constructed to avoid downsveam erosion. • Failure of this type of temporary swctuce may result in flooding and sevece erosion. If the secaona! downdtain is not sized correcdy, the runoff can spill over the dcain sides causing gully erosion, and po~enaal failute of the svucmre. ESC32 ~ R~cUe~ ; Construction Handbook 5- 49 March, 1993 ~~ i ~' '~ Additional Information - Slope Drain ~' REFERENCES i Best Management Pracaces and Erosion Convol Manuat for Construcdon Sites, Flood Control District of Maricopa ' County, Arizona, September 1992. + "Dnft - Sedimenta6on and Erosion Convoi, An Inventory of Cucrent Pracuces". U.S.E.P.A., April, 1990. ~ Sto~mwater Management Water for the Puget Sound Basin, Wathin ton State De 8 partrnent of Ecotogy, 'Ibe Tuhnicai ~ Manual - Febmary 1992, PubGcauon # 91-75. ~ Water Qualiry Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regional Planning Agency - November 1988. ~ ' ~ ~ ~ ' ~ ~ ' ~ ' ~ ' II ESC32 ~ ~ L ~ ~~.` ; truction Handbook 5- 50 March, 1993 ~~ ; ,! ~' '! i ~ 1 1 ' ~ i ' ' , ~ ~ ~ ~ ~ ' ' Additional Information - stoPe orain 11' ` EARTH ~IKE ~ ,, ;, ~ =~~ RIPRAP APRON SIDE SLOPE = 2:1 EARTH OIKE CORRUGATED- METAL PIPE ~~ ~IIi~"lil~~~lll~~~lll~~~~ ~ I 1=1 ! I-, I 1=! I 1= ' . 111,-,1-1, i~~- :111,;.~~~_ ~ STANDARD FLARED ~ ENTRANCE SECTION ~ MIN. INLET SLOPE 3x MIN. . p,12- (DJ 6D Construction Handbook 4' MIN. ~ AT ~ESS THAN 1z SLOPE 0 ~ 3D+2 RIPRAP SHOULD CONSIST OF 6" DIAMETER STONE PI.ACED AS SHOWN AND SHOULD BE A MINIMUM OF 12" IN THICKNESS. PIPE SLOPE DRAIN (RIGID) ESd2 5- 51 March, 1993 2`~ ~ r , ' , r r r ~ ' ' , ~ ~ ~ ~ ~ ~ B M P: OUTLET PROTECTION Objectives Housekeeping Practices ~~. ;~ ~ ~~" `~° Contain Waste ~ ~ ~~ . , ~ • ', ~ ~ ,y ~, Minimize Disturbed Areas ~• „ .i . i r ~ ~ - Stabilize Disturbed Areas .~-_... T~ ~ ,, t v , ~~ ~ ro ect Slopes/Channe ~ '~ ~ \ ~ Contro! Site Perimeter ~~ Controllnternal Erosion GENERAL DFSCRIPfION Rock ouUet protecuon is a physica! device composed of rock, grouted ri prap; or concre[e Targeted Pollutants rubble which is placed at the outlet of a pipe to prevent scour of the soil caused by high ~ Sediment pipe flow velociues, and to abso~b Dow energy to produce non-erosive velocities. ~ Nutrients SUTCABLE APPLICATIONS O Toxic Materials Wherever discharge velociues and energies at the oudecs of culvens, conduit~ or ~ Gi/ B Grease channels are sufficient to erode the nezt downsveam reac6. ~ Floatable Materials Rock oudet protecuon is best suited for temporary use during conswction because it is usually less expensive and easier to install ~an c ~ Other Construcfion onaete a rons or ener dissipators. P gY Waste A sediment vap below the pipe oudet is recommended if runoff is sediment laden. ~ Llkety m Havs • PernL3nent rock riprap protection should be designed and sized by the engineer as part Stgnlncant Impaer of tbe culven, conduit or channel desiga . ~ Proba6le Low o~ • Grouted riprap should be avoided in areas of fr d h Unknown lmpac7 eeze an t aw because cbe grou[ will break up. Implementation INSTALLATION/APPLICATION CRITERIA Requirements Rock outlet protecuon is effecflve when the rock is sized and placed propedy. When this 0 Capita/ Costs is accomplished, rock oudets do much to limit erosion a[ pipe outlets. Rock size should be ~ O&M Costs increased for 6ig6 velocity flows. General recommendations for rock size and IengW of Q Mainten oyUet protecUon mat are presented in the additional information shee4 Best results ue ance obtained when sound, durnble, angularrock is used, CalTtans S~andard $pecifications or ~ Treining the local municipality can pravide addiuonal specificauons for construcdng ouUet prorec- ~ Suita6ility lor uon ddvices. Slopes ~SY. REQUIREMENTS Maintenance ~ - Inspect after each significant iain for erosion and/or disrupuon of the rock, and i repa r immediately. ~ - Grouted or wire-ued rock ri prap can minimize maintenance re i H~9h ~ Low qu rements. • Cost - CalTtans Cost Schedule gives regional cost ranges. E S V 4 0 LIMITATIONS • Large stocros oFten wash away the rock outlet protection and leave the azea suscep- tible w erosion. • Sedimen[ captured by the rock outlet protection may be difficult to remove without BeSt removing tf~e rock Managemen • Oudet protecuon may negauvely impact the channe] habitat. PI'eCtICeS Construction Handbook 5- 53 March, 1993 (/`1 '~ ~ ~~ ,! L~ ~ ~ ~ ~ ' ' ~ r ~ ~ i ~ ' Additional Information - outiet Protect~on Outlet protution is needed where discharge velocities and energies at the outlets of culverts, conduits or channels are suCficient to erode the immediate downsveam reach. 7'his pracuce protuts the inlet or oudet Gom developing small eroded pc~ols (plange pools), and protuts against gully erosion resulung from scounng at a culvert mouth. Rock ouUet protection is usually less expensive and easier to insiall tban concrete aprons or energy dissiparors. It also serves to trap sediment and reduce flow velocities. As with most channel design proju~s, depth of ilow, roughness, gradient, side slopes, discharge rate and velociry should be considered in the outlet design. Compliance to locat and state regulations should also be considered while working in emironmentally sensiuve streambeds. General recommendauons for rock size and Iength of oudet protecuon mat is shown in the rock oudet protecuon figure. Best resuits are obtained when sound, durabie, anguiar rock is used. Rock depth and oudet protecuon IengW aze govemed by che discharge pipe size, bu[ hydraulic calculauons and velociues should be used to determine lengih. Your locai municipality or CalTrans should be consulted for appropnace sizing criteria in your area. REFERENCES Bes[ Management Practices and Erosion Convol Manual for ConsWCtion Sites, Flood Convol District of Mariposa County, Arizona, September 1992. County of Sacramenco Improvement Standards, Sacremento County - May 1989. Environmental Criteria Manual, City of Austin, T'X, 1989. Erosion and Sediment Control Handbook, SJ. Goldmv~, K. Jackson, T.A. Burszrynsky, P.E., McGraw Hill Book Company, 1986. Handbook of Steel Drainage & Highway Construcaon, American Iron and Steel Insuwte, 1983. Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Govemments, Jun 1981. Sto~mwater Management Water for the Puget Sound Basin, Washington State Departrnent of Ewlogy, The Technical Manual - Febcuary 1992, PubGcaaon # 91-75. I ESC40 1 Water Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Pracuces, Tahce Regional Planning Agency - November 1988. ; Construction Handbook ' S- 54 March, 1993 ~pC! f '' 'I ~ ~' i ,~ r ~ ~ ~ , ' ~ ' ~ ~ , ~ r Additional Information - Outlet Protection ~ n ~ ~ Lo ° ~O~ ~O ~ FILTER FABRIC SECTION A-A PIPE OUTLET TO FLAT AREA WITH NO ~EFiNE~ CHANNEL FILTER FABRIC~ ~ECTION 8-8 PIPE OUTLET TO WELL-DEFINED CHANNEL I ESC40 I ~ Construction Handbook 5• 55 March, 1993 ~ ' I v La = LENGTH OF APRON do = INSIDE PIPE DIAMETER w = APFON WIDTH d = APRON THICKNESS NOTES 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, OR CONCRETE 2. PIPE DIAMETER, APRON DIMENSIONS, AND AVERAGE ROCK SIZE FOR RIPRAP ARE BASED ON THE DESIGN F~OW R,qTE AND VELOCITY. La AND ROCK SIZE MUST BE SEf TO SIOW THE FLOW TO NON-EROSIVE VELOCITIES (e.g., LESS THAN 10 fps). SEE CALTRANS AND LOCAL AGENCY DESIGN CRITERIA FOR APPROPRIATE SIZING CRITERIA. 3. d= 7.5 TIMES THE MAXIMUM ROCK SIZE DIAMETER BUT NOT LESS THAN 6 INCHES. ~ ~ ~ ' ~ r ~ , ~ ' r ~ ~ ~ ' ' ~ ~ ~ ~ ' BMP: SILTFENCE objectives Housekeeping Prectlces -_- _ _ - _ _ _ Contein Wasie - - - - - Minimize Distur6ed Areas - - = - - _ Stabilize Disturbed Areas - ~ Protoct Slopes/Channels ~ - ~ ' ontrol Site Perimeter ~ ~ ~ ontrollnteme/ Erosio i GENERAL DFSCRIPTION Targeted Pollutants A silt fence is made of a Filter fabric whic6 has been entrenched, attached to suppocting ~~~~~t poles, and someumes backed by a wire fence for support The silt fence detains sedimena t i ~ N t laden water, promodng sedimentation behind the fence. u r en s ~ Toxic Matena/a SUTTABLE APPLICATIONS ~ Oil S Grease . Along the perimeter of We site. t b/ ~ F/ M i / Below tbe IQg of a cleared stope. oa e e eter a e Along streams and channels. ~ Other Cansirvciion ~~~ ~~ porary spoil azeas. W~ta Across swales with carchmenrs less than 1 acre. ~ Llks/y tv Hsvs Below other small cleared azeas. • Stynrflcanr Imp.er ~ Probeb/s Low or INSTALLATION/APPLIC Unknownlmpaet ATION Use principally in areas where sheet flow occurs. Impiementation Insrall along a!evel conm~r, ~ water dces not pond more than 1.5 feet at any point Requirements No more than 1 acre, 100 fe, or 0.5 cfs of concentreted flow should drain to any point along tbe silt fence. Q Capita/ Coata Tum ends of fence uphill. ~ Q OdM Coata Provide area behind the fence for mnoff ro pond and sediment to seale (approz. 1200 ~~~R~enance sq. fc per acre draining to t6e silt fence). Select filter fabric which retains 85% of tlie soi1, by weight, based on sieve analysis, ~ Training but is not finer tLan an equivalen[ opening size of 70. ~ Suitability /or Slopea >5'X REQUIREMENTS Maintenance - Inspect wetkly and afrer each rainfall. - Repair wherever fence is damaged. - Remove sediment when it reaches 1/3 tLe height of the fence. • Cost (souice: EpA, 1992) ~ High Q Low - Avecage annual cost for installation and maintenance (ass~es 6 month useful life): $7 per linea! foot ($850 d i ESC50 per ia nage acie) LIMTTATIONS Do not use w6ere 85% of the soil, by weight, passes tlwugh a No. 200 sieve because the fIIter fabric will dog. Do not place fence on a slope, or across any contour line. Do not use in sueams, channels, or anywhere flow has concentrated Best . Do not use in locaflons w6ere ponded wazer may cause flooding. Managemen p~CtiCes ; Construction Handbook 5• 62 March, 1993 ~~ ; '' '' ~' ~ ~ ' r r r ' ~ ~ ' r , ~ Additional Information - s~it Fence A silt fence is a temporvy sediment bamer consisting of filter fabric stretched across and attached to supporung posts, entrenched, and, depending upon the atrength of the fabric used, suppoReA wi[h wue fence. Silt fences t:ap sediment in two ways: (1) by intercepdng and deraining tmall moim s of sediment from dis[urbed areas during consiruction opera- [ions in order tD promote sedimentation behind the fence; and (2) by decreasing the vetocity of low flows (up to 0.5 cfs) in swales. Siit fences may be used for perimeter control, placed upstream of the point(s) of dischuge of s6eet tlow from a site. 'Ibey may also be used as interio~ controls below disturbed azeas w6ere nmoff may ocas in the form of sheet and rill erosion, and pecpendicular to minor swales or dicch 6nes for up to one acTe conuibuting drainage azeas. Silt fences are generally ineffective in lceations where the tlow is concentra[ed and are oNy applicable for sheet a overland tlows. In~ta l la tion~Annli cadon Planning: Silt fences are generally most effuuve when the following placement aiteria ace followed • Limit [he upsveam drainage area ro 1 acre or less w6en used alone or in combination wi~h sediment basin in a larger site. • 'ILe maximum slope perpendiculaz to the fence line should be I:1. • Limit the maximum sheet or overland Ilow path IengtL tn any point along t6e fence to 100 feet • Limit the concentreted flows reaching the fence to 0.5 cfs. Silt fences are preferabie to straw bazriers in many cases. Laboratory work at tbe Virginia Highway add Transpoctation Reseatch Council has shown that sIIt fences can trap a muc6 higher percentage of suspended sediments ihan can straw bales. While the failure rate of silt fences is lower than that of strnw bacriers, there aze many instances where silt fencrs have been impmperly installed. The following installation metl~ods can improve perfocmance and should be followed: • Consavtt tl~e silt fence along a level conrour. • Silt fences should remain in place until ihe disdubed area is pe~manendy stabilized. • Provide sufFicient coom for runoff tn pond behind the fence and tn allow sediment removal equipmen[ to pass between the silt fence and tces of slopes or otbu obstructions. About 1200 sq. f~ of ponding azea s6ould be provided for every acre draining ro the fence. • Tum the ends of the Filra fence uphill tn prevent stotm water from flowing around the fence. • I,eave an undisturbed or stabilized area immediately downslope from the fence. • Do not place in live streams or intermittently flowing channels. Design: Selection of a filter fabric is based on soil conditions az tbe consuvcdon site (which affect the equivalent opening size (EOS) fabric specificaaon) and cha+~*~<dcs of the support fence (w6ich affect the choice of tensile strength). T6e designer should specify a filter fabric that retains tbe soil found on the constxuction site yet will have openings large enough to permit dcainage and prevent clogging. Tl~e following criteria is rernmmended for selection of the equivalent opening s've: 1. If 50 pe~cent or less of the soil, by weigh4 will pass the U.S. standard sieve No. 200, select the EOS ro retain 85 percent of the soil. 'ILe EOS should not be finer than EOS 70. 2. For all otha soil types, the EOS should be no larger tban tbe openings in the U.S. Staadard Sieve No: 70 [0.0083 in. (0.21 mm.)] ezcept where d'uut dischazge to a stream, lake, or wedand will occur, then the EOS should be no larger tban Standard Sieve No. 100. ESC50 1 Construction Handbook 5- 63 March, 1993 ~~ 2 , r ' , ' ~ ~ , ' r ~ , , r r r ~ r i Additional Information - Silt Fence To reduce the chance of clogging, it is preferable to specify a fabric witL openings as lazge as allowed by tbe criteria. No fabric should be specified with an EOS smaller tban U.S. Standard Sieve No. 100 (0.0059 in. (0.15 mm.)j. If 85 percent or more of a soil, by weig64 passes through the openings in a No. 200 sieve [0.0029 in. (0.074 mm.)J, filter fabric should no~ be used. Most of the panicles in such a soil would not be retained if the EOS was [oo Iazge, and they would dog We fabric quickly if the EOS was small enough to capture ihe soil. iLe fence should be supported by a wiie mesh if ihe fabric selected does not have sufCicient strength and bursting sttength cbazacterisacs for the planned application ( as ruommended by the fabric manufacturer). Filter fabric material should contain ulrreviolet cay inhibicors and scabilizeis to provide a micumum of siz montLs of ezpecced ~sable consvuc- uon life at a temperanue range of 0° F. to I20' F. Installadon Guidelines: Flter fences aze W be constructed on a level conrour. Sufficient area should ezist be6ind ~e fence for ponding ro occur without tlooding or overtopping the fence. Posts s6ould be spaced a maximum of 6 feet apazt and driven securely into the ground a minimum of 30 inches. A trench should be excavated appmximately 8 inches wide and 12 inc6es deep along the line of poscs and upslope from tl~e bazrier. When standard strengtl~ filter fabric is used a wue mesh support fence s6ould be fastened securely to the upslope side of the posu using heavy-duty wire staples az least 1 inc6long, tie wires or hog rings. 'Ibe wire should extend inro the trench a minimum of 4 inches. 'ILe standard suength filter Cabric should be stapled or wired to tbe fence, and 40 inches of the fabric should eztend in[o the trench. When extra-strength Filter fabric and closer post spacing are used ~~e w'ue mesh support fence may be eliminated and tLe filter fabric stapled or wired direcdy to the posts. Avoid the use of joints. TLe filtec fabric should be purchased in a conanuous roil, then cut tn the length of the barrier: When joints aze necessary, filter cloth should be spliced togelber only az a support post, with a'minimum 6 inc6 overlap, and both ends securely fastened [o [he post 'ILe trench should be backfilled with compacte~ native material. Reanimm n e Maintenance: Inspect monthly during dry periods and immediately after each xainfall. Repair as necessary. Sediment must be removed w6en it reaches approzimately one th'ud ~he height of the fence, upeciatly if heavy raias are ezpected Filter fenccs should not be removed until the upslope area has been pem~anendy stabilized. f.imi ation¢ ~ • Filter fences will creaze a temporary sedimentation pond on the upstream side of ihe fence and utay cause temprxary flooding. Fences not constructed on a level contour will be overtopped by concentrated tlow resulting in failuce of the filter fence. • Filter fences aze ~ practical wheie ]arge flows of water are involved, hence the need ro restrict the'u use to dreinage areas of one acre or less, and flow cares of less [han 0.5 cfs. • Problems may azise hom inco~rect sclection of pae size andlor improper instalJation. • Do not allow water depth ro ezceed 1.5 f~ at any point • Improperly installed fences are subject to failure from undercutting, overlapping, or collapsing. I ESC50 I ' Construc[ion Handbook 5- 64 March, 1993 Z~y 1 , I ,; Additional Information - s~it Fe~ce ~ REFERENCES , I Best Management Practiccs and Frosion Convol Manual for Construcaon Sites, F7ood Control Disuict of Maricopa Coimty, Arizona, September1992. + Environmental Action Manual, City of AusUn, Texas, 1989. ~~ . Manual of Standards of Erosion and Sedimwt Control Measures, qssociation oF Bay Area Governments, Jun 1981. ~ Proposed Guidance Specifying Managemen[ Measuies for So~uces of Nonpoint Pollution in Coastal Waters, Work t~ Group Working Paper, USEPA, April, 1992. 1~ Sedimenta6on and Erosion Convol Practices, An Introductory of Curnnt Pcactices (Draft), USEPA, 1990. i Stormwater Management Manua( for The Puget Sound Basin, Washingcon gtate I~P~ent of Ecology, Public Review ~4 1991. '~ Warer Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Ta6ce Regional Planning Agency - November 1988. LJ ~ i ,! ~ ~f ,i , '` '~ Construction Handbook 5 - 65 ,' ~ ESC50 II March, 1993 ,`~ 2 ,' ~ ~. i ~ '~ ~' ~ ' ~i ~ ~ ' ~~ , r r ' 1 r ~ , Additional Information - siit Fence - 2" X 4" WOQD POST. STANDARD OR BETTER OR EDUA~ ALTERNATE:STEEL FENCE POST ~~ ; FILTER FABRIC MATERIAL 60" WIDE ROL~S. USE STAPLES OR WIRE RINGS TO ATTATCH ~ FABRIC TO WIRE j' , -2"X2" 14GAWIRE j FABRIC OR E~UIV. c N O cD ~ ~ ~ . ... . ... ~%\~%\~7~~'.. . -.. . .,\~%\~%\~%\~%\\%~":.. ' ~ ~ ~ I O +} _ - - _ _ I ~. "' I I LBURY BOTTOM OF FILTER MATERIAL ~ ~ I I IN 8" X 12" TRENCH I ~ ! I ~' ~.,oY I I FILTER FABRIC MA ~~ 2" X Z"' 14 GA WIRE FABRIC OR EOUIV. FOLD 8 SET FILTER FABRIC INTO SOIL ,2~ ~ N BACKFILL AND COMPACT THE EXCAVATED SOIL IN TRENCH AND ON BOTH SIDES OF FIITER FENCE FABRIC 2" X 4' WOOD POST A~T:. STEEL FENCE F FLOW m ~ ESC50 I Construction Handbook 5-66 March, 1993 Z1~ ~~ ~~ '' '~; I '~ ~ i '~ ,~ ~ ' r r ' ' , r ' BMP: SAND BAG BARRIER Objectives Nousekeeping Prac6ces Confain Waste ' ~ ~ . , , ~.~ r ,-. Minimize Disturbed Areas . Sfabilize Disturbed Areas . ~~' '~' rotectSlopes~Channe ` I ontrol Site Perimet ontrol lntemal Erosio GENERAL DEFINTTION Targeted Pollutants Stacking sand bags along a level contour creates a barrier which detains sediment-laden watet, ponding water upstream of the barrier and ptomodng sedimentation. ~ Sediment SIJTTABLE APPLICATIONS ~ Nutrienta Along tLe perimeter of the site. ~ Toxk Materia/s Check dams across stteams and channels. ~ Oil6 Grease Along strcams and channels. Q F/oatab/e Meteris/a Bazrier for utiliry tienches in a channel. Q Oth C Across swales with small cauhments. er onatroction Westa Division dike or berm. Below the tce of a cleared slope. ~ Llksty w Hevs Create a temporary sediment aap. slynulcant ~mp.ct AroUnd temporary Spoil areaz. 0 Protiabh Low or Unknown /mpxt Below otber small cleared azeas . Impiementation IIVSTALLATION/APPLICATION CRTIERIA Requirements May be used in drainage areas up to 5 aaes. Install along a level contour. ~ Capital Coata Base of sand bag ba[rier should be az least 48 inches wide. ~ OSM Coata Height of sand bag banier should be a[ least 18 inc6es hig6. ~ Maintenaxe 4 inch PVC pipe may be installed betwcen tbe top layer of sand bags ro drain tacge ~ Tralning ~~ ~oWS. Q Suitability /or • Provide ama behind barsier for nmoff to pond and sediment to setUe, size xcording to Slopea >5'X sediment trap BMP criteria (ESC55). • Place ~jpyy the toe of a slope. • Use sand bags ]azge enough and sturdy enough to withstand major flooding. REQUIREMENTS • Maintenance ~ High ~ Low - Inspectaftereachrain, - Reshape ot replace damaged sand bags immediately. ~~~~~ Remove sediment when it ieaches siz inc6es in depth. Cost - Sand bag baaieis aze moic cosdy, bu[ typically have a longer useful life than other bacriers. LIMITATIONS Best Sand bags aze more expensive than other bacriecs, buc atso more durabte. Managemen Hurlap should not be used for sand bags. P~eCtIceS ' ~onscrucaon Handbook 5- 71 March, ]993 / 2ti' ,~ , r~ I ,~ 1 '1 I ~' ~ 7 ,I Additional information - Sand Bag Barrier Snitahle A(~ i afiont . Sand bag becros may be used during construction acavities in stream beds and utility consavcdon in chacu~els, temporary channel crossing for conswction equipmen4 etc. Sand bag berms may aLSO be installed para11e1 [o roadway conswc- aon. Sand bag berms may atsp be used to create temporary sediment ttaps, retenaon basins and in place of straw bales or silt fences. E~mples of applications include: • Check dams across sueam channels. • Bacrieis for utility trenches or o[her constnicdon in a sveam channel. • At temporary c6annel aossings. ' • May be used on a slope where straw bales and silt fences are not appropriate. • As a diveision dike. • Embanl~ent fa a temporary sediment basin a retention basin. • Sediment barriecs neaz the tce of slopes. • At construction perime~er. Adv n ao .S • Provides a semi-permeable bamer in potendally wet areas. More peimar~ent than silt fences or straw bales: ~ ~ ~ ~ r ~ r r r • Allows for easy relocation on site tn meet changing needs during consttuction. InStallatinn/An(} i a ipp Sand bag bazriecs may be used for sediment trapping in ]ocations where silt fences and straw bale baixiex~ are not stmng enough. In addition, sand bag barsiets azc appropriaze to use w6en construction of check dams or sumps in a stream is undesirable. The sand bag berms can provide the same funcdon as a check dam without dishsbing the stream or vegetauon. TLe sand bag berm will also allow a small sediment retention area [o be created prior [o construcdon of final detrntion 6asins. For installation of a sand bag beiut; We following aiteria should be observed: • Drainage Area - Up to five (5) aars. • Height of Becm - 18 inches minimum 6eigh4 measured from the mp of tt~e ezisting gro~md az the upslope toe tn the top of the battier. • Width of Berm - 48 inches minimum width measured az the bottom of tLe barrier; 18 inches az the top. • Sand bag Size - Length 24 to 30 inches, width 16 to IS inches and thiclmess siz (6) to eight (8) inches. Weight 90 to 125 potmds. • Sand bag Material - Polypropylene, polyethylene or polyamide woven fabric, minimimm unic weight four (4) ounces per square yard, mullen bu:st strengtL ezceeding 300 psi and ulhaviolet stability ezceeding 7p percenG Use of butlap is discouraged since it rots and deteriorates easily. • Grdde of Sand - Coazse sand, giavel. " • Runoff water slwuld be allowed to flow over the tops of the sand bags or through four (4) inch pplyvinyl chlaide pipes embedded below the top layer of bags. • Area behind Ne sand bag bazrier should be established accortling ro sizing aiteria for sediment trap BMP (ESC55). REFERENCES Best Management Pcacrices and Fmsion Controi Manual for Constmcdon Sites, Flood Control District of Maricopa co~mty, ,~iZ«,a. september 199z. Water Quality Management Plan for tbe Lake Ta6ce Region, Volume II, Handbook of Management ESC52 Practices, Tahce Regional Planning Agency - November 1988. l:onstrucnon Handbook , $ _ ~2 ' March, 1993 \ J ~ 2~~ ' ~' ~ ~ ' ' ' r ' ~ ~ ~ - r r , ' ~ ~ ~ ' , Additional Information - sar,d ea9 aarr~er 18" MIN 4" PVC PIPE ~ 6" MIN FLOW z ~ OIAMETER ROCK -~ - - - ~ m o no nQnQnQn 48" MIN 48" MIN 12" ~ROSS-SECTION WOVEN FABRIC SANDBAG FILLED WITH COARSE SAND-MIN WEIGHT 40 LBS. 4" PVC PIPE FOR DRAINAGE DEPENDING ON FIELD CONDITIONS 24" MIN ~ . FRONT VIEW SAND BAG BERM. ESC52 a.. AYy~~~ Construction Handbook 5-73 March, 1993 2.~'~ ~ , ' ' ~ ~ ' ~ ~ ' ~ , ' ~ r ~ ~ r r r BMP: STORM DRAIN INLET PROTECTION Objectives Housekeeping Pracbces Contain Was-e •......,. ; :~..i•:i.• ~~ Minimize Dlsfwbed Arees .. .:, e •`•-'=.~:~•,..0 ;i.~ Stebilize Dlsfur6ed Arees _~ i • ~ ~ ~ ~- ~ °'e Protect Slopes/Channels 111=.~~ ~- ontrol Site Perimefe , ontrollntemal Erosion GENERAL DEFINITION Targeted Polluta~ts Devices of various designs whic6 detain sediment-laden runoff and allow the sediment it tn settle prior [o discharge into a stocm drain inlet or ptch basin. ~ Sediment SUITABGE APPLICATIONS ~ Nutrients Every srocm drain inlet receiving sediment-]aden ninoff should be pmtected, either by Q Taxic Materiale covering tLe inlet or promoting sedimenration upstream oF the in1eL ~ Oll b Grease Q Fbatable Materia/s INSTALLATION/APPLICATION Q Other Constroction Five types of inlet protecdon are presented below, however, it is recognized t6a[ other Waste effective methods and proprietary device, exist and may be selected: - Fi]ter Fabric Fence: Appropriatc for drainage basins less than one acte with less ~ Llkety w Hevs tt~an a 5 percent slope. 51yn/Reanelmpeet - Biock and Gcavel Filter. Appropria[e for flows greater than 0.5 cfs. ~~babw Low or - Giavel and Wire Mesh Filter: Used on curb or drop inlets wtiae constiuction Unknown Impaet equipment may drive over the iNeL - Sand bag bamer: Used [o create a small sediment tcap upstream of inlets on Implementatlon sloped, paved streets. peyuiremants - Ezcavated Drop Inlet Sediment Trap: An excavated area around the inlet to (iap Q Capital Coata sedimen[ (see Sediment Trap ESC 55). Q O~M Caab Select the appropriace type of inlet protection and design as refeaed to or as described in tbis faa s6eet. Q Maintenance • Usc only fa dreinage areas smaller than one acre unless a sediment irap first intercepts ~ Training the runoff. ity for ~ Su • Provide area around tbe inlet for water to pond witLout flooding stmcuues and ~ Sb >5'X ProPertY• ~Q~~ • Maintenance - Inspec[ wakly and after each rain. S High ~ Low - Replace clogged filter fabric or stone filtecs immaliately. - Remove sediment when depth ezceeds half tbe height of the filter, a half the E SC54 depth of the sediment trep, - Remove as soon as upstream soils are stabilized and sheets aze swept Cost (source: EPA, 1992) - Average annual cost for installation and maintenance (1 year useful life) is 5150 per inle~ Best Managemen Practices Construction Handbook g _ ~9 March, 1993 21~ , ';. BMP: STORM DRAIN INLET PROTECTION (Continue) ' ~ ~~ „ ~ ~' ~ ~ ~ LIMTTATIONS • Drainage area should not exceed 1 acre. • Runoff will bypass protected inlets on slopes. • Ponding will occur az a protected iNet, with possible shoa-tern~ flooding. • Stiaw bales are ~ effecdve for inlet pro~ection. I ESC54 I Construction Handbook 5 - 80 ''. March, 1993 Z~q ,! ~ 1'•~ ~ i '~ '~ i ,~ ~~ ~! ~ , ~ ~ ~ Additional Information - storm Drain Inlet Protection S[orm draio inlet praecdon consists of a sediment filter or an impounding area azoimd or upstream of a s[orm drain, drop inlet, orcurbinleL ThiserosionandsedimentadonwnrrolBMPprevenrsexcessivesedimentfromenreringstormdrainagesystems prior to pemlanent stabilizaaon of the disnubed acea All on-site stom drain inlets should be protected. Off-site, inlets s6ould be praected in areas w6ere consWCUOn acuvity tracks sediment onto paved azeas or where inlecs receive rvnoff ~om disnubed areas. Tnstalla[io lAnli ation ri rria - Planning Iarge amounts of sediment may enter the storm drain system w6en storm drains aze installed before tLe upslope drainage azea is stabilized, or where conswttion is adjacent [o an existing storm drain. In cases of extreme sediment loading, the storm drain itself may clog and lose a major ponion of its capaciry. To avoid tbese problems, it is necessary tn prevent sedimenc from en[ering the systcm at tbe inlets. Inlet controt measures presented in this handbook should not be used for inlets draining more [han one aae. Runoff from lazger disrorbed areas s6ould be fi~t routed thraigh a Temporary Sediment Trap (see ESC 56). Different types of inlet protection aze appmpriate for different applicaiions depending on site conditions and We type of inle~ Inlet protection methods not presen~ed in this bandbook should be aQproved by the local storm water management agency. Genecai Design and sizing criteria: • Grates and spaces azound all inlets s6ould be sealed to prevent seepage of sediment-laden water. • Ezcavate sediment sumps (w6ere needed)1 to 2 feet with 2:1 side slopes aroimd the inleG Installa[ion procedures for filter fabric fence: a. Plxe 2 inch by 2 inc6 wooden stakes around the perimeter of the inlet a maximum of 3 feet apart and drive them at Ic 8 inches into the ground. Ihe stakes mus[ be at leas[ 3 feet long. b. Excavate a uenc6 approximatety 8 inc6es wide and 12 inches deep azound the oucside perimercr of the stakes. c. Stapie the filter fabric (for matecials and specifications, see Silt Fence ESC 50) to wooden stakes so thaz 32 inches of fabric extends out and can be formed into the trench. Use heavy-duty wire staples az least one inch in length. d. Backfill the t:ench with 3/4 inch or less was6ed gravel all the way around. U-stailation procedure for block and gravel Cilter: a. Place hardwaze cloth or comparable wice mesh wid~ one-half inch openings over the drop inlet so tLat the wire extends a minimum of 1 foot beyond each side of the inlet structure. If more than one strip is necessary, overlap the strips. Place filter fabric ova ttie wire mesh. b. Place concrete blocks lengthwise on their sides in a single row around the perimeter of the inlet, so thac the open ends face outward, not upward. 'ILe ends of adjacent blocks s6ould abuL 'Ibe height of the bamer can be vazied, depending on design nceds, by stacking combinations of blocks that ace 4 inches, 8 inches, and 12 inches wide. The row of blocks s6ould be at least 12 inches but no greater tban 1A incbes high. . c. Place wire mesh over the ourside vecticai face (open end) of the concrete blocks to prevent stone from being washed tLrough the blocks. Use hardware cloth or comparable wire mesh with one half inch openings. d. Pile washed stone against the wire mes6 ro the top of the blocks. Use 3/4 to 3 inch graveL Lutallation procedure for grsvel and wire mesh ftlters: a Place wire mesh over tLe drop inlet so [hat the wne extends a minimum of 1 foot beyond each side of the inlet strucdue. Usc hardwaze cloth a comparable wire mesh with one-half inc6 openings. If more tban one strip of inesh is necessary, overlap the strips. Place filter fabric over wire mesh. I ESC54 I ~ Construction Handbook 5- 81 March, 1993 ~y~0 l~`• ~ ~ , r~ I '~ ~ ~' i '~ ~ i ' ' ' ~ ~ r i ' ~ Construction Handbook 5 - 82 Addltl0t18~ (I1fOC1118t1011- Storm Drain Inlet Protection b. Place 3/4 to 3 inch gravel over tbe filter fabric/w'ue mesh. The deptt~ of tbe gravel shouid be at least 12 inches over the entire inlet opening (see attac6ed figure). Itutallation procedure [or sand bag barrier: a Use sand bag made of geotexdle fabric (not burlap), and fill with 3/4 in. rock or 1/4 in: pea giavel. b. Conswct on gendy sloping sveet c. Leave room upstream of bamer for water to pond and sedimen[ [o setUe. d. Place several layecs of sand bags--overlapping the bags and packing them tightly tngether. e. Leave gap of one bag on tbe top row to serve as a spillway. F7ow from a severe storm (e.g., 10-year storm) should not overtop the curb. M~intenanre Re.n fr m.n c • For filter fabric fences: [nspections should be made on a regulaz basis, especially after large storm events. If the fabric becomes clogged, it s6ould be replaced. Sediment should be removed when it reaches approximately one-half the height of the fence. If a sump is used, sediment shouid be removed when it Fdls approximately one-half the depth of tbe hole. • For gravel fdters: If the gravel becomes dogged with sediment, it must be carefully removed from the inlet, and eitLer cleaned or reptaced. Since cleaning gravel at a wnswction site may be difficul4 use t6e sediment-laden stone instead az fdl and put fresh stone around the inlet. • 'ILe inlet pcntection should be removed 30 days afrer tt~e upslope azea has been fully stabIlized. Any sediment amund the inlet must be cazefully removed and disposed. Best Management PcuUces and Erosion Convol Manual for Constcuction Sites, Flood Control District of Maricopa Co~mty, Arizona, September 1992. "Ihaft - Sedimentadon and Erosion Conirol, M Inventory of Cucrent Pcacuces", U.S.E.P.A., April, 1990. Erosion and Sediment Control Handbook, SJ. Goldman, K. Jackson, T.A. Bucsetynsky, p.E., McGraw Hill Book Company. Manua! of Standards of Frosion and $ediment Control Measures, Association of Bay Acea Govemments, June 1981. Proposed Guidance Specifying Management Measuies for Sources of Nonpoint Pollution in Coastal Waters, Wak Group Working Paper, USEPA, April, 1992. Stocmwatcr Management Water for We Puget Sound Basin, Washington State Departmeot of Ecology,'Ihe Technical Manuai - Febcvary 1992, Publication # 91-75. Sto:m Water Pollution Pcevention Handbook, First Fdiuon, State of Califomia, Deparmient of Transportation Division of New Teshnology, Materials, aad Research, October 1992. ~ L'-J ESC54 ~ P,.a~. March, 1993 2$~ t 'f ,' ',~ i ''~ 1 '~ 1 '1 I '? 'i '~ i ~ ~ ~~ ~ ~ ~ ~ ~ ,~ ~ Qdd1~10112~ ~l1f0~t118t10f1- Storm Drain Inlet Protection i //~ / OVV ~Oi / O FC~ /~ oO O C // ~ ~/ ~ ~p'o~ ~//j ~ /~ ~~ WIRE MESH WITH 1/2" OPENINGS GRAVEL FILTER (3/4" TO 3" GRAVEU SEDIMENT- CONCRETE GRAVEL AND WIRE MESH FILTER FnR CURB INLET 12,• ~ /-FILTERED WATER ~~ ~ . ' ~CURB IN~ET I E5C5a 1 Construction HandUook 5-SA March, 1993 '~ ~ 2`~ ''~ : ,'~ ~ ~ ~ ~ ~ r ~ ~ 0 r ~ ~ r I~ C~I BMP: SEDIMENTBASIN Objectives Housekeeping Practices ~ Contain Waste Minimiza Disturbed Areas - Sfa6alizeOistur6edAreas ~ Protecf Slopes/Channels - ,~cWy~~~`~~Y Confro! Site Perimeter I I ~ j 1 ~I _ ~_ ~ ControllntemalErosion GENERAL DEFINTTION Targeted Poilutants A pond created by excavation or conswcting an embanF~ent, and designed to retain a detain runoff sufficiently to allow excessive sediment to settle. ~ Sediment 0 Nutrienta SUTI'ABLE APPLICATIONS Q Toxic Malerisla At the oudet of all disaubed watec56ed 10 ac~es or larger. At the ouUet of smaller dismrbed watersheds, as necessuy. ~ Oil6 Grease . Where pos[ constfuction detention basins will be located. ~ Floatab/e Meteris/s Should be used in association with dikes, tempcx-ery channels, and pipes used to divert ~ Other Conairuuion disuubed azeas into tbe basin and undisturbed azeas azound tbe basin. Waste INSTALLATION/APPLICATION ~ ukety w Havs Construc[ before clearing and gading work begins. srynlRunt /mpact Do p(Zj locate in a stream. ~ Q Robeble Low or All basin sites should be located w6ere failuie of rhe embankment would not cause loss unknown ~mpeet f lif / o e property damage. Large basins are subject to state/local dam safety requiremenrs. ~mplementation Securely anchor and install an and-seep collar on the oudet ~ nser, and p'pe/ ' provide an Requirements emergency spillway for passing major floods (see local flood control agency). Q CepBal Costa ThebazinvolumeshauldbesizedtocaphuecunofFfroma2-year,24-6ourstorm orothet , appropriate design stocros specified by the local agency. Adetendon time of 24 to40 houcs Q 0&MCosta should allow 70 tn 80 percent of sedimen[ ro settle. ~ Alaintenaxa The basin volume consists of two mnes: Q Training - A sediment storage zone at least 1 foot deep. Q S it bili / - A settling wne az least 2 feet decp. u a ry or Sbpes >5~X The length tn settling depth ratio (LJSD) should be less than 200. • 'IbelengtLtowidthratioshouldbegreaterthan6:l,orbaftlesarerequiredtoprevents6ort dreuiting. REQUIREMENTS • M~n~Oa°~ ~ High ~ Low ~ - Ins ett wcekl and h 6 i p y a er eac ra n. - Remove sedimenc whae the sediment storage zone is half full. C A E S C56 osC verageannualcostforinstallationandmaintenance(2yearusefullife, source: EPA 1992) , - Basin less tban 50,000 fL3: $0.40 pet fL3 ($700per d~ainage acie) - Basin size greater tban 50,000 ft3: $0.20 per ft3 (5350 per drainage acre) BCSt Managemen Practices ; Construction Handbook 5- 90 March, 1993 ~j~ ~ i '. ~~ i ', ~ ~i ~ i , V ~ ' ~ r ~ ~ ~ , ~ i ~ ~ ~ 1 Additional Information - sedimenc rraP 3. The trap is removed and the area stabilized when tLe upslope dreinage area has been properly stabilized. 4. All cu(-and-fill slopes should be 3:1 or f7atter. 5. When a riser is used, all pipe join6 must be watertighL 6. Whenariserisused,atleasttbetoptwo-thirdsoftherisers6allbeperforatedwithl2-inchdiameterholesspaced8inches vertically and 10 to 12 inches horizontally. (See Sediment Basin, ESC56) 7. When an earth or stone outlet is used ibe outlet crest elevation should be a[ least 1 foot below tbe top of the embani~enL 8. When a aushed stone outlet is used, the crushed stone used in the ouUet should meet AASHTO M43, size No. 2 or 24, o~ iLS equivalent such as MSHA No.2. Gravel meeung the above gradauon may be uxd ifrnuhed stone is notavailable. Bes[ Management Practices and Erosion Control Mannal for Conswcuon Sites, Flood Convol Disuict of Mazicopa Coimty, Rough Dcaft -July 1992. "Draft - Sedimentation and Erosion Control, An Inventory of Cutrent Practices", U.S.E.P.A., April, 1990. "Environmen[al Criteria Manual", City of Ausuq Texas. Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Govemments, June 1981. Proposed Guidance Specifying Management Measu:es for Sources of Nonpoint Pollution in Coastal Waters, Work Group Worlcing Paper, USEPA, April, 1992. Stormwazer Management Water for the Puget Sound Basin, Washington State Department of Ecology,lLe Technical Manual - Febtuary 1992, Publication # 91-75. Water Quality Management Plan for the Lake Tahce Region, Volume II, Handbook of Management Practices, Tahce Regional Planning Agency - November 1988. I ESC55 I Construction Handbook 5-89 March, 1993 ^ ~ / ' ' ~ ~ ' ' ' r ~ ~~ ~ ~ ~ ~i ~ ~ ~ ' BM P: SEDIMENT BASIN (Continue) LIMTfATIONS • TLe basin should have shallow side slopes (minimum 4:1) or be fenced to prevent drowning. • Sites with very fine sediments (fine silt and clay) may require longer detention times for effecuve sediment removal. • Basins in excess of 25 feet hcight and/or an impoundiog capacity of 50 ac. ft must obrain approval from Division of Safety of Dams. Standing water may cause mosquitos or other pests to breed. • Bazins in ezcess of certain deprh and srorage volume criteria must meet State Divuion of Safery of Dams (DSOD) and local safety requvements. I ESC56 I ~ i.ons[ruc[~on tlantlbook 5• 91 March, 1993 ;~g~j (/« ~ ~ ~ 1 ' ~ ~ ' r ' ~ , ' ~ ~ ~ ~ ~ Additional Information - Sediment Basin A sediment basin is a controlled storm water telease swcnue formed by excavation or by constructing an embanlm~ent of compacted soil across a drainageway, or other suitable locatioa Its piapose is to collectand store sediment from sites cleared and/or gaded during conswction or for extended periods of time before reestablishmenc of pecmanent vege[ation and/or constiuction of pecmanent drainage swctures. It is intended to trap sediment before it leaves the conswction site. 'ILe basin is a temporary measure (with a design Gfe of 12 to 18 months) and is to be maintained until the site area is permanenUy protected against erosion or a peimanent detenuon basin is constructed. Sedimentation basins aze suitable for nearly all types of construcuon projects. Whenever possible, constiuct the sedimen- tation basins before clearing and grading work begins. Bazins should be located at the stormwazer ouUet fmm the site, but not in any nauual or ~mdisacbed sveam. A typical applica[ion would include tempaary dikes, pipes, and/or channels [o diveit runoff to the basin iNeL Many development projects in Califomia will be required by local ordinances to provide a storm water detenaon basin for post-construction flood control, desilta[ion, orstocm waterpolludon conirol. A temporary sediment basin may be wnstructed by rough grading tbe post-construcuon control batins early in ~he project. Sediment basins vap 70-80 percent of the sediment which flows inro them if designed accocding to this handbook. Tl~erefore, tl~ey should be used in conjunction wiU~ erosion contml prectices suc6 as temprn-uy seeding, mulching, diversion dikes, etc., to reduce the amount of sediment flowing into the basin. Tns allation/Anp i atinn rit ria~ Planning: To improve tbe effecdveness of the basin, it should be locazed to inrercept nmoff from the largest possible amount ofdisturbed azea The best locations are grnecally low areas below d'uturbed azeas. Dtainage intv the basin can be improved by the use of diversion dikes and ditc6es. 'Ibe basin mus[ notbe located in a stream but should be located to trap sediment-laden runofF IZL&1IC it entecs the stream. 'I'he basin should ~ be located where i[s failtue would result in the IoSs of life or intetruption of tbe use or service of public utiliues or roads. Design: • T6e sedimenta[ion basin volume consists of two zones: - The sediment storage zone (at least 1 foot in depi6). - A settling zone at least 2 feet in depth. The sedimentadon basin may be famed by partial excavation and/or by construcaon of a compacted embanF~ent. It may have one or more inflow points. A securely anc6ored riserpipe with an and-seep collar is the principal outlet, along with an emergency overflow spillway. A solidriserpipe with two 1-inch diameterdewatering holes locatedat the top of the sedimentstorage vol~e on opposite sides of the risetpipe usually provides sufficientdetenflon time fa basins dtaining about 10 acres. Rock, rip-rap, or other suitable ouUet protection is prpvided to reduce erosion az the riser pipe outlet Setlling Zone Volimte I ESC56 11 ~ J i..ons[ructwn HanUUOOk 5- 92 March, 1993 „Qfp ' (f~ Additional information - sed~ment eas~r, 'Ibe settling zone voi~e is determined by the following equation: (V) = 1.2(SD)Q / VSED Q= design inflow based on U~e peak discharge from a specified design storm (e.g., a 2-year, 24hout durarion design storm event) from [he tributary drainage area as computed using the metbods required by the local flood convol agency. Provide a minimum of 67 cubic yards of settling volume per acre,of drainage if a design storm is not specified. uSED =~ ~~~8 velociry of the design soil patticle. 'Ibe design particie chosen is medium silt (0.02 mm). This has a settling velociry (VSED~ of 0.00096 h/sec. As a general rule it will not be necessary to design for a patticle of size less tban 0.02 mm, especially since the surface azea requirement increases dramatically for smaller particle sizes. For example, a design pazticle of 0.01 mm requires about ~hree times We surface area of 0.02 mm. TVote also that choosing VSED of 0.00096 fdsec equates to a surface area (SA) of 1250 sq. fG per cfs of inflow. SD = settling depth, w6ich should be at least 2 ft, and no shallower than the average distance from inlet ro the outlet of We pond (L) divided by 200 (i.e., SD > LJ200). 1 ~ ~ ~ ~ ~ ' ' ' Total sediment basin volume and dimension are determined as oudined below: a. 7Le derails shown in tbe attached figure may be useful in designing the sedimen[ basin. b. Determine basin geometry for the sediment storage volume calculated above using a minimum of 1 ft depth and 3:1 side slopes from the bottnm of the basin. Notc, the bazin bottom is level. c. Eztend the basin side slopes (at 3:1 maxJ as necessary to obtain the settling zoce volume as detemined above. d. Adjust tLe geometry of the basin to effeciively combine the se[tling zone volume and sediment storage volumes while prescrving the depU~ and_side slope criteria e. Provide an emergency spillway with a cfest elevation one foot above the top of the riur pipe. f. 'Ibe ratio between the basin length and width of the pond shoutd either be greater than 6:1, or baffles should be installed to p:event short-circuiting. T: mi atiORS Sediment traps and ponds must be instalied only wiWin the properry limits. Failure of ihe stmcnue must na iesult in loss of life,damagetohomesorbuildings,orinterruptionofuseorserviceofpublicroadsautilities. Also,sedimentaapsandponds aze attracuve to c6ildren and can be very dangerous. Local ord'mances cegarding health and safety must be adheced to. If fencing of the pond is required, the type of fence and its location shall be shown in the SWPPP and in t6e construction specifica[ions. • Gecerally, temporary sedimentation ponds are limited to dreinage of 5 acres or more. • Sedimentpondsmaybecapableoftreppingsmallersedimentpaniclesifadditionaldetenaontimeispmvided However, they are most effecuve whrn used in conjimction with otber BMPs such as seaiing or mulching. • Ponds may become an "attractive nuisance" and care must be taken to adhece to all safety practices. • Sediment ponds designed xcording tn tbis handbook are only prdcfically effecbve in removing sediment down tn about tbe medi~ silt siu hacuon. Sediment-laden runoff with smaller size hactions (fine silt and clay) will pass through untreated emp6asizing N~e need to s~abilize tbe soil quickly. wnscrucnon tianauooK 5 - ')3 i ESC56 I March, 1993 ~i"~ , ~' ; '' i '~, ~ 1 '~ 1 '~ Additional Information - sed~ment Bas~r, REFERENCES A Current Assessment of Ucban Best Management Pracdces: TechniqUes for Reducing Nonpoint Source Pollution in the Coastal Zones, Metropolitan Washington Council of Governments, March, 1992. Best Management Practices and Frosion Convol Manual for Consuuction Sites, F1ood Control Disuict of Maricopa Coimty, Rough Draft - July 1992. Draft - Sedimenta6on and Erosion Control, An Invenwry of C~urent Pracrices, U.S.E.P.A., April, 1990. Environmental Criteria Manual, City of Ausdn, t'e~cas. Guidlines for the Iksign and Constiuction of Small EmbanF~en[ Dams, Division of Safety of Dams, California Depazt- ment of Water Resources, March 1986. Manual of Standards of Erosion and Sediment Control Measures. Association of Bay Area Govemments, Jun 1981. Proposed Guidance Specifying Mnangement Measures for Sources of Nonpoint Pollution in Coastal Water, Work Group Working Paper. tJSEPA, April, 1992. S[otmwater Management Water for the Puget Sound Basin, Washington State Departrnen[ of Ecology.'ILe Techciical Manual - February 1992, Publication # 9I-75. ' Water Quality Management Plan for the Lake Tahce Region, Volume II, Han~ook of Management Pracbces, Tahce Regional Planning Agency - November 1988. ic ~ ~ ~ ~ I ESC56 I '~ ~ Construction Handbook 5- 94 March, 1993 '4 ~ ,~_`, f v- ' ; ~ ~ ~` ; ~ ~ ~ ~ ~ , ~ ~ ~ ' ~ 1 ' ~ ~ ~ ~ ~ ' Additional information - sediment sasin n~ ~ . ~ - TOP VIEW ~ ~ ~ ~ ~ ~~ ~..r DEfENT10N TIIAE: 24 TO s0 NOURS ~ - --- SEOMENT 5i0qacE vOIMAFi ~A +RM MOO pp~p~jKT y~y.~T . YO TRA1M IIOpI _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ ___ _ ' _ _ rRw zm~w ovrM _ z rt. ~.a ov~w . C :•. ::. _ __ _ _ _ _ _ _ _ _ _ __ _ _ _ - _ xo.o.r trw< _ -- 3' w%. ~ rr. uu. mn~ rvnw*m waw or~ua ~ ~o ~ M 11~Y6 J~C2T DETENTION TiME: 24 TO d0 HOURS SIOE VIEW .rn.~m cauw SEDEMENT STORAGE VOLUME: 67 CU. YD. PER ACRE TEMPORARY SEDIMENT BASIN I ESC56 I Construction Handbook 5-95 March, 1993 nt~~ //~~ i ~' ~ ~ ~ ~ ' ~ ' ~ 1 1 1 ~ r ~ i ~ ~ r r ~ i APPENDIX B SCALE SWPPP SITE PLAN (TO BE PROVIDED) ~ APPENDIX C EROSION CONTROL PLAN (TO BE PROVIDED) Za~ r i ~ a ~ i ~ ~ i ~ APPENDIX D ~ SAN DIEGO BAS1N PLAN ~ WATER QUALITY OBJECTIVES ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Za~ ' ~ ' ~ ' 1 1 ' 1 1 1 ' 1 ' ' ' 1 1 1 ~ WATER QUALITY CONTROL PLAN FOR THE SAN DI EGO BASI N(9) SEPTEMBER 8, 1994 CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD SAN DIEGO REGION Z°~ , ~ CHAPTER 3 WATER QUALITY OBJECTIVES ' ' ' INTRODUCTION ....................................................................... 1 WATER ~UALITY OBJECTIVES ................................................... 1 WATER ~UALITY 08JECTIVE DESIGNATION UNDER THE PORTER-COLOGNE WATER ' QUALITY CONTROL ACT .. . . . . . . . . , , , , , ~ WATER QUALITY OBJECTIVE DESIGNATION UNDER THE CLEAN WATER ACT ........... 2 ~ STATE AND FEDERAL ANTIDEGRADATION POLICIES . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 2 FEDERAL ANTIDEGRADATION POLICY . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . .. . . . . 3 STATE ANTIDEGRADATION POLICY . . . . . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . 3 ' ' ' ' ' ' DESIGNATED WATER QUALITY OBJECTIVES . ... . . . . . . . , , , , , .............................. GENERAL ANTIDEGRADATION OBJECTIVE .. .. .... . .... . . .. .. .. ...... ........ .... .. OCEAN WATERS ................................................................ OCEAN PLAN AND THERMAL PLAN . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. .. . . . . DISSOLVED OXYGEN ..................................................... HYDROGEN ION CONCENTRATION (pH) . . . . . . . . . . . . . . .. . . .... . . . . . . .:. . .. . . . INLAND SURFACE WATERS, ENCLOSED BAYS AND ESTUARIES, COASTAL LAGOONS AND GROUND WATERS . . . . . . . . . . . . . . . . . . . . . . .. . . . . . .. . . .. ..... . ........... THERMAL PLAN . . . . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AGRICULTURAL SUPPLY BENEFICIAL USE . . . . . . . . . . . . . . . .. ... ... . . . ... .. ... AMMONIA, UN-IONIZED . ........... ........... .... .. ... ... ................ BACTERIA - TOTAL AND FECAL COLIFORM . . . . . . . . . . .. . .. .. .. . . . .. . . .. .... . . BACTERIA - E. COLI AND ENTEROCOCCI . . . . : . . . . . . . .. .. . .. . . . .. . . . .. .... .. . BIOSTIMULATORY SUBSTANCES . . . . . . . . . . . . . . . . . . . . . . . . .. . . . ... . .......... BORON ................................................................. CHLORIDES ............................................................. COLOR ................................................................. DISSOLVED OXYGEN ..................................................... FLOATING MATERIAL ..................................................... ' FLUORIDE ............................................................... HYDROGEN ION CONCENTRATION (pH) . . . . . . . . . . . . . . . . .. .. . .. . .. . . ... .. . ... INORGANiC CHEMICALS - PRIMARY STANDARDS . . . . ... . . ..... . . .... . .. .. . . . . TABLE 3-4. MAXIMUM CONTAMINANT LEVELS FOR INORGANIC CHEMICALS SPECIFIED IN TABLE 64431-A OF SECTION 64431 3 4 4 4 4 4 5 5 5 5 5 6 6 7 7 8 8 8 8 8 OF TITLE 22 OF THE CALIFORNIA CODE OF REGULATIONS AS AMENDED JANUARY 3, 1995 . . . . . . . . . . . . . . . ...... .. . . ... ... . . . 9 ' TABLE 3-5. LIMITING AND OPTIMUM CONCENTRATIONS FOR FLUORIDE SPECIFIED IN TABLE 64431-B OF SECTION 64431 OF TITLE 22 OF THE CALIFORNIA CODE OF REGULATIONS AS AMENDED ' ' JANUARY 3,1995 . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . IRON .. ......:.:................:.........:.......................... MANGANESE .... . METHYLENE BLUE - ACTIVATED SUBSTANCES (MBAS) . . . . .. . . ... . . . ....... . . NITRATE ... ....................................................... OIL AND GREASE ....................................................... ORGANIC CHEMICALS - PRIMARY STANDARDS . . . . . . . . . . . . .. . . . . . . . . . 10 9 9 10 10 10 TABLE 3-6. MAXIMUM CONTAMINANT LEVELS FOR ORGANIC CHEMICALS SPECIFIED IN TABLE 64444A OF SECTION 644A4 , OF TITLE 22 OF THE CALIFORNIA CODE OF REGULATIONS AS ' AMENDED JANUAHY 3, 1995 . . . . . . . . . . .. . . . .. . . PERCENT SODIUM AND ADJUSTED SODIUM ADSORPTION RATIO .. .... .. . . ... 12 , PESTICIDES ............................................................ PHENOLIC COMPOUNDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..... : . : . . . . . . .. . . RADIOACTIVITY . ... ...... , 13 13 13 TABLE 3-7. MAXIMUM CONTAMINANT LEVELS FOR RADIOACTIVITY SPECIFIED IN TABLE 4 OF SECTION 64443 OF TRLE 22 OF THE , CALIFORNIA CODE OF REGULATIONS AS AMENDED JANUARY 3,1995 .............. .......... .............. 14 SECONDARY DRINKING WATER STANDARDS .. .. . . . ... ..... . . .... .... .. .. .. 14 TABLE 3-8. SECONDARY MAXIMUM CONTAMINANT LEVELS FOR ~ CONSUMER ACCEPTANCE LIMITS SPECIFIED IN TABLE 64449- A OF SECTION 64449 OF TITLE 22 OF THE CALIFORNIA CODE OF REGULATIONS AS AMENDED JANUARY 3, 1995 .... ..... ..... 14 1 WATER QUAIITY OBJECTIVES September 8, 1994 v '~ L~ SEDIMENT .............................................................. 14 ' SUSPENDED AND SE7TLEABLE SOLIDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 SULFATE ............................................................... 15 TASTES AND ODORS . . . . . . . . . . . . . . . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . .. . . . 15 TEMPERATURE ......................................................... 15 ' TOTAL DISSOLVED SOLIDS . . . . . . . . . .... . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 15 TOXICITY .............. ............................................. 15 TOXIC POLLUTANTS ..................................................... 16 TRIHALOMETHANES ..................................................... 16 ' TUR8IDITY ..... .... 16 WATER ~UALITY OBJECTIVES OF INIAND SURFACE WATERS . . .. . . . . . . . . . . . . . . . ... . 17 WATER ~UALITY OBJECTIVES OF GROUND WATERS . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 WATER QUALI'TY CRITERIA .. . . . . . . . . . . . .. . . . ... . . . .. . . . . . . . . . . . . . . . . . . . . . . .. ... . 17 ' REFERENCES . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. . . . . .. . . . . . . . . . . . ... . . 1 . .................. g INDEX .................... 18 ........................................................... ' REPRINT OF RESOLUTION NO. 6&16 . . .. . .. . .. . .. ..... . . . ... .. . . . ... . . .. .. .. . . ... . .... . . 19 TABLE 3-1. GUIDELINES FOR INTERPRETATION OF WATER ~UALITY FOR IRRIGATION ........ 20 , TABLE 3-2. WATER ~UALITY OBJECTIVES FOR INLAND SURFACE WATERS . .. . . . ... . .. . .. .. 22 TABLE 3-3. WATER QUALITY OBJECTIVES FOR GROUND WATER ... .. . .. ... ... .. ... .:. .... . 27 , ' ~ ' t ' ~ ~ ~ 1 , ' WATERQUALITYOB,IECTIVES September8, 7994 2°~ ~ ' 3. WATER QUALITY WATER QUALITY OBJECTIVE I OBJECTIVES DESIGNAT/ON UNDER THE ' PORi ER-COLOGNE WATER ' INTRODUCT/ON QUAUTY CONTROL ACT ~ The purpose of this chapter Significant points regarding the designation of water ' = is to designate the water r. quality objectives for all quality objectives for waters of the state under the Porter-Cologne Act are: surface and ground waters in the Region. These water • Water quality objectives must ensure the quality objectives are reasonable protection of beneficial uses and ' necessary to protect the the prevention of nuisance, recognizing that it beneficial uses designated in Chapter 2 may be possible for the quality of the water to . be changed to some degree without ' California WaterCode Section 13050(h) defines °water ° unreasonabiy affectin beneficial uses. (Califomia Water Code ~13241) quality objectives as follows: "The limits or levels of water quality constituents or • Protection of beneficial uses may not require thatwaterqualityobjectivesprotecttheexisting ' characteristicswhichareestablishedlorthereasonable quality of water. However, water quality protection olbeneficial uses of water or the prevention objectives cannot be set at a level that would of nuisanca within a specific area. ° permitwater quality to change to such a degree ' By definition, water quality objectives must protect the that the beneficial uses designated for protection are unreasonably affected. most sensitive of the beneficiai uses which have been (Cai'rfomia Water Code §13241) designated for a water body. Water quality objectives may be numerical values for water quality constituents • Water quality objectives must ensure that the ' ornarrativedescriptions. Waterqualityobjectivesmust water will be suitabie for the beneficial uses be based upon sound scientific water quality criteria which have been designated for protection. needed to protect the most sensitive of the beneficial (California Water Code §13241) uses which have been designated for a water body. ' Water quality objectives must be as stringent or more ~ • In establishing water quality objectives the stringent than water quality criteria. Numerous key , Regional Board must provide for the terms used throughout this chapter are defined in the reasonable protection of all beneficial uses Glossary which is inciuded as Appendix A of this Basin which are designated for protection, taking into ' Plan. account existing water quality, environmental WATER QUAL/TY OBJECTI VES andeconomicconsiderations. Cal'rfomiaWater Code Section 13241 provides that the Regionai Board shall consider, but is not Iimited to, the ' Like the designation of beneficial uses, the designation following factors in establishing water quality of water quality objectives must satisfy all of the objectives: applicable requirements of the CaI'rfomia Water Code, ' Division 7(Porter-Cologne Act) and the Ciean Water Act Califomia Water Code Se ti 13241 i ~ Past, present, and probable future . , c on prov des that each Regional Water Quality Control Board shali beneficial uses of water; estabiish water quality objectives for the waters of the state i.e. (ground and surtace waters) which, in the ~ Environmental characteristics of the ' Regional Board's judgement, are necessary for the hydro~raphic unit under consideration, reasonable protection of beneficial uses and for the inc~uding the quaiity of water availabie prevention of nuisance. The Clean Water Act Section thereto; 303 requires that the State adopt water quali e ' objectives (called water quality criteria) for surfac ~ Water quality condition~ that could waters. The requirements of both Acts applicabie to the reasonably be achieved through the designation of water quality objectives are summarized coordinated controi of ail factors which ' below. affect water quality in the area; °~ Economic considerations; '. ~ The need for developing housing within the region; and ' ~ The need to develop and use recycled water. ' WATER QUALITY O&IECTiVES 3-1 September 8, 1994 2°~~ ' WATER QUALITY OBJECTIVE ' DESIGNAT/ON UNDER THE CLEAN WATER ACT ' Section 303 of the Clean Water Act requires the State to submit to the U.S. Environmental Protection Agency (US EPA) for approval, all new or revised water quality standards which are estabiished for surtace and ocean waters. Under federal terminology, water quality standards consist of the beneficial uses e~umerated in Chapter 2 and the water quality objectives contained in this chapter. Significant points regarding the designation of water quality objectives for suAace waters pursuant to the Clean Water Act are: • ,~ ' , ' '~ ' '~ ' '~ ' ' '• ~ W ater quality objectives are called water quality criteria in the Clean Water Act. Water quality criteria (i.e., water quality objectives) are defined as constituent concentrations, levels, or narrative statements, representing a quality of water that supports a particular surface water use. Water qualiry criteria are qualitative or quantitative estimates of the concentration of a water constituent which, when not exceeded, wiil ensure water quality sufficient to protect a designated beneficial use. Water quality crfteria should reflect the latest scientific knowledge on the identifiabie effects of pollutants on public health and welfare, aquatic I'rfe, and recreation [40 CFR 131.3(b)]. States must adopt water quality criteria (i.e., water quality objectives) that protect designated surtace water beneficial uses. For surface waters with multiple beneficial use designations, the water quality criteria shall support the most sensitive beneficial use [40 CFR 131.11(a)(1)]. States must adopt water quality criteria (i.e., water quality ob~ectives) for surface waters which are based upon US EPA guidance documents or other scient'rfically defensible methods. Economics are not considered in the development of waterqualitycriteriaforsurface waters under the Clean Water Act [40 CFR 131.11(b)J. Water quality criteria (i.e., water quality objectives) for surface waters can be either numeric or narrative specifications for water quality based on physical, chemical and toxicological data, and scientific judgement. Where numericai specifications cannot be established, narrative criteria must be established based upon biomonftoring methods [40 CFR 131.11(b)]. The term "water quality criteria" has rivo meanings under the federal Clean Water Act. In one context, water quality criteria is equivaient to water quality objectives. In other words, water qualitycriteria is the standard that a state must impose to protect a surface water beneficiai use. in another context, the term ' WATER ~UALITY O&IECTIVES 3-2 "water quality criteria" reters to scientific information US EPA has developed on the relationship that the effect of a constttuent concentration has on human heatth, aquatic life, or other uses of water. US EPA has published information in documents such as the "Gold BoolC (US EPA, 1986) and in various individual criteria documents. STATE AND FEDERAL ANTIDEGRADATION POLIC/ES Water quality objectives must aiso conform to US EPA reguiations covering antidegradation (40 CFR Section 131.12) and State Board Resolution No. 68-16, Statement of Policy with Respect to Maintaining High Quality of Waters in Califomia. Application of the antidegradation provisions to the standard setting process requires supporting documentation and appropriate findings whenever a standard (water quality objective or beneficial use) is made less restrictive to accommodate the discharge of pollutants or other activities of man. FEDERAL ANTIDEGRADAT/ON POL/CY US EPA water quality standards regulations mandated under the Clean W ater Act require that each state have an "antidegradatiorf policy for surface waters [40 CFR 131.6(d)]. Each state's policy must, at a minimum, be consistent with the foliowing three principles (hereinafter referred to as the "federal antidegradation policy') set forth in 40 CFR 131:12(a): (1) The first principle requires that ail existing instream water uses shall be maintained and protected. (2) The second principle protects waters whase quality exceeds tevels necessary to support propagation of fish, shelifish, and wildl'rfe and recreation in and on the water. For these waters, limited water quality degradation may be allowed 'rf necessary to accommodate important economic or social development in the area in which the waters are located and if the water quality is adequate to protect existing uses fully. (3) The third principle requires maintenance and protection of all high quaiity waters which constitute an outstanding national resource. The federal antidegradation policy serves as a"catchalf water quality standard, to be applied where other water quaiity standards are not specific enough tor a particular water body or where other water quality standards do not address a particular pollutant. The policy also serves to provide guidance for standard setting and for other regulatory decisions, to determine when additional control measures should be required to maintain instream beneficial uses or to maintain high quality surface waters. The federal antidegradation policy is not an absolute bar to reductions in surtace water quality. Rather, the policy requires that reductions in water quality be justified as necessary to September 8, 799a Zo~1 , ' LJ ' ~ ~ ' ~ 1 ' accommodate important sociaf and economic devebpment. STATE ANTIDEGRADATION POLICY Water quaiity objectives for waters of the state must conform to State Board Resolution No. 68-16, Statement of Policy with Respect to Maintaining High Quality of Waters in Califomia. Under State Board Resolution No. 68-16, which applies to all waters of the State, ihe Regional Board and the State Board must have sufficient grounds to adopt findings which demonstrate that any water quality degradation will: (1) Be consistent with the maximum benefit to the people of the State; (2) Not unreasonabiy affect existing and potential beneficial uses of such water; and (3) Not result in water quality less than described in the Basin Plan. Resolution No. 68-16 establishes a general principle of nondegradation, with fiexibility to ailow some changes in water quality which is in the best interests of the State. Changes in water quality are allowed onty where it is in the public interest and beneficial uses are not unreasonably affected. The State Board has interpreted Resolution No. 68-16 as incorporating the three part principles set forth in the federal antidegradation policy. The terms and conditions of Resolution No. 68-16 serve as a general narrative water quality objective in all state water quality control plans. A reprint of Resolution No. 68-16 is provided in the back of this Chapter on page 3-19. ' DESIGNATED WATER QUALITY OBJECTIVES ~ , ' ' ' ' , The water quality objectives designated for the waters of the San Diego Region are listed below. These water quality objectives are necessary to protect exis6ng and potential beneficial uses described in Chapter 2 and to protect existing high quality waters of the State. The water quality objectives will be achieved primarily through the establishment of waste discharge requirements, and through the implementation of this water qualiry control plan. The Regional Board, in establishing waste discharge requirements, will consider potential effects on beneficial uses within the area of influence of the discharge, the existing qualityof receiving waters, and the appropriate water quality objectives. The Regional Board will make a tinding as to the beneficial uses to be protected within the area of influence of the discharge and establish waste discharge requirements to protect those uses and to meet water quality objectives. The water quality objectives are stated in italics and arranged first by the water body type to which they apply (e.g., ali waters; all ocean waters; and all inland surface, enclosed bay and estuaries, coastal lagoons, and ground waters). W ithin each water body type, the water qualiry objectives are alphabetized byconstituent. In most cases the water qualiry objective is preceded by a generaf description ot the constituent limited by the objective. The objectives vary in applicability and scope, reflecting the variety of beneficial uses of water which have been ident'rfied. Where numerical limits are specified, they represent the maximum levels of constituents that wiil aliow the beneficial use to continue unimpaired. In other cases, an objective may tolerate natural or "background Ievels of certain substances or characteristics but no increases over those values, or may express a limit in terms of not adversely affecting beneficiai uses. An adverse effect or impact on a beneficial use occurs where there is an actual or threatened loss or impairment of that beneficial use. GENERAL ANTIDEGRADATION OBJECTIVE The following objective shail apply to all waters of the State wfthin the Region. Genera/ Antldegradation Water Quality Objective: Wherever the existing qualityof wateris betterthan the quality ot water established herein as objectives, sueh existing quality shall be maintained unless othenvise provided by the provisions of the State Water Resources Control Board Resolution No. 68-16, °Statement of Policy with Respect to Maintaining High Quafiry of Waters in Califomia' including any revisions thereto, or the federal Antidegradation Policy, 40 CFR 131.12 (forsurface waters only). OCEAN WATERS ~ ~.-. ~~_;~; The foilowing objectives shall apply to aIl ocean waters of the State within the Region: OCEAN PLAN AND THERMAL PLAN Ocean Plan and Thermal Pfan Water Quallty ObJectlve: The terms and conditions of the State Board's 'Wale~ Qualiry Control Plan for Ocean Waters of Califomia' (Ocean Plan), "WaferOualityControl Plan forControl of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of Califomia" (Thermal Plan), and any revisions thereto a~e incorporated into this Basin Plan by reference. The terms and conditions of the Ocean Plan and Thermal Plan apply to the ocean waters within this Region. DISSOLVED OXYGEN Adequate dissolved oxygen is vital for aquatic life. Depression of dissolved ouygen levels can lead to fish kiiis and odors resulting from anaerobic decomposition. Dissolved ouygen content in water is a function of water temperature and salinity. ' WATER ~UALITY OBJECTIVES 33 September 8, 7994 2q$ ' Water Quality Objective lor Dissolved Oxygen: ' The dissolved oxygen concentration in ocean waters shall not at any time be dep~essed more than 10 percent from that which occurs naturalty, as the result ol the discharge of oxygen demanding waste materials. , HYDROGEN /ON CONCENTRATION (pH) The hydrogen ion concentration of water is called "pM. ' The acidity or alkaiinity of water is measured by the pH factor. The pH scale ranges from 1 to 14, with 1 to 6.9 being acid, 7.4 to 14 being alkaline, and 7.0 being neutral. Ranges {pH) of 6.5 to 9.0 are considered ' harmless. A change of one point on this scale represents a ten-fold increase in acidity or aikalinity. Many pollutants can alter the pH, raising or lowering it excessively. In some cases even smail changes in pH ' can harm aquatic biota. The pH changes can alter the chemical form of certain constituents, thereby increasingtheirbioavailabilityandtoxicity. Forexample a decrease in pH can resuk in an increase in dissolved ' metal concentrations. Ammonia, which is a major component of sewage discharges, can be completely safe at pH 7.0 and extremely toxic to fish at pH 8.5 for the same total ammonia concentration. ' Water Quality Objective for pH: The pH value shall not be changed at any time more 'than 0.2 pH units lrom that which occurs naturally. INLAND SURFACE WATERS, I ENCLOSED BAYS AND ESTUARIES, COASTAL LAGOONS ' AND GROUND WATERS The following objectives apply to all inland surface waters, enclosed bays and estuaries, coastai lagoons, ,and ground waters of the Region as specified below. THERMAL PLAN ' Therma! Plan Water Quality Objectlve: The terms and conditions of the State Board's "Water Ouality Control Plan for Control of Temperature in the 'Coastal and Interstate Waters and Enclosed Bays and Estuaries of Califomia" (Thermal Plan) and any revisions thereto a~e incorporated into this Basin Plan by reference. The terms and conddions of the Thermal ' Plan apply to thelnland Surface Waters, Enclosed Bays and Estuaries, and Coastal Lagoons within this Region. AGR/CULTURAL SUPPLY BENEF/CIAL , USE Water Ouality Objective Jor Agriculturai Supply: ~ Waters designated for use as agricultural supply (AGR) shall not contain concentratrons of chemical constituents in amounts that adversely a(fect such 'beneficial use. AMMON/A, UN-lONlZED Ammonia is a pungent, colorless, gaseous alkaline compound of nitrogen and hydrogen that is highly soluble in water. Un-ionized ammonia (NH,) is toxic to fish and other aquatic organisms. In water, NH~ exists in equilibrium with ammonium (NH, ) and hydroxide (OH') ions. The proportions of each change as the temperature, pH, and salinity of the water change. Water Qua/ity Objective for Un-ionized Ammonia: The discharge of wastes shall not cause concentrations oi un-ionized ammonia (NH~ to exceed 0.025 m¢i (as N) in inland surface waters, enGosed bays and estuaries and coastal fagoons. BACTER/A - TOTAL AND FECAL COL/FORM Fecal bacteria are part of the intestinal flora of warm- blooded animals. Their presence in surface waters is an indicator of poilution. Totai coi'rform numbers can include non-fecal bacteria, so additional testing is often done to confirm the presence and numbers of fecal coliform bacteria. W ater quality objectives for numbers of total and fecal coliform vary with the uses of the water, as shown below. (1) Waters Designated for Contact Recreation (REC-1) Beneficial Use ~ Water Quality Objectlve for Contact Recreation: In waters designated for contad recreation (REC-1), the fecal coliform concentration based on a minimum of not less fhan Sve samples for any 30-day period, shall not exceed a log mean of 200/100 mf, nor shalf more than 10 percent of total samples during any 30-day period exceed 400/100 ml. (2) WatersDesignatedforNon-ContactRecreation (REC-2) Beneficial Use WaterQualityObjecfive forNon-contact Recreatlon: !n waters designated for non-contact rec~eation (REC- 2J and not designated for contact recreation (REGt), the average fecal coliform concentrations for any 30- day period, shall not exceed 2,000/100 mi nor shall more than 10 percent of samples collected during any 30-day period exceed 4, 000/f 00 ml. (3) Waters W here Shelifish May Be Harvested for Human Consumption (SHELL) Beneficiai Use Water Quality Objeciive for Shel/tish Harvestirtg: !n waters where shellfish harvesting for human consumption, commercial or sports purpases is designated (SNELL), the median total coli/orm concentrafion throughout the water column for any 30- day period shall not exceed 70/100 mi nor shall more than 10 percent of the samples collected during any 30- day period exceed 230/100 ml for a five-tube decimal , WATER QUALITY O&IECTIVES 3-4 September 8, 1994 2°~q , ' ' , , ' ' ' ' ' LJ ' ' ' , , , ' dilution test or 330/100 ml when a three-tube decimal dilution test is used. (4) Bays and Estuaries Water Ouality Objective for Bays and Esiuaries: In bays and estuaries, the most probable number of colrform organisms in the upper 60 feet of the water column shall ba less than 1,000 per 100m1(10 perml); provided that not more than 20 percent of the samples at any sampling station, in any 30-day period, may exceed 1,000 per f00 ml (f0 per ml), and provided further that no single sample when verified by a repeat sample taken within 48 hours shall exceed 10,000 per 100 (100 per m!). BACTER/A - E. COLI AND ENTEROCOCCI (1) San Diego Bay Water Quality Objecfive for E. Cod: !n San Diego Bay where bay waters are used for whole frsh handling, the density of E. coli shalf not exceed 7 per ml in more than 20 percent of any 20 daily consecutive samp/es of bay water. (2) Waters Designated for Contact Recreation (REC-1) Beneficial Use The US EPA published E. coli and enterococci bacteriological criteria applicable to water5 designated for contact recreation (REC-1) in the Federal Register, Vol. 51, No. 45, Friday, March 7, 1986, 8012-8016. WaterQuality ObJectlve for Enterococcl and E. Coli: US EPA BACTERIOLOGlCAL CRfTER/A FOR WATER CONTACT RECREATIOM~ (in colonies per 100 ml) Freshwater Sa/fwater enteio- E Col! entero- cocd ~ci steaay srere (all arees) 33 726 35 Maximum (designated beach) 61 235 104 (moderately orfiynrryused area) 708 406 276 (inhequently used area) 151 576 500 'The cnteria were published in the Federal Register, Vol. 51, No. 45/Frrday, March 7, 1986/8012-8016. The criteria are based on: Cabelli, V_ J. 1g83. Heelth EHects Cntena lor Menne Recreatlonal Waters. U. S. Environmental Protection Agency, EPA 600/1-80-037, Crncinneti, Ohio. Dulour, A. P. 1984. Hea/th EI/ects C6teda /or Fresh Recreational Waters. U. S. Environmental Protection Agency, EPA 600/1 •84-004, Cincinnatl, Ohio. ZThe EPAcritena apply to watercontact iecreation only. The criteria provide for a level of protection based on the frequency of usage of a given water contact recreation area. The cnteria may be employed in special studies within this Region to differentiate between pollution sources or to supplement the current coliform objectives for water contact recreation. BIOSTIMULATORY SUBSTANCES Excessive growth of algae and/or other aquatic piants can degrade water quality. Algal blooms somehmes occur naturally; however, they are often the result of waste discharges or nonpoint source poilutants. Aigal blooms depress the dissolved oxygen content of water and can result in fish kilis. Algal blooms can also lead to problems with taste, odors, coior, and increased turbidity. Floating algal scum and algal mats are also an aestheticaliy unpieasant nuisance. This general condition is known as eutrophication. Water Quality ObJectlves for Biostimulatory Substances: Inland suAace waters, bays and estuaries arM coasta! lagoon waters shall not contain biastimulatory substances in concentrations that promote aquat~c growth to the extent that such growths cause nuisance or adversely aflect beneficial uses. Concentrations of nitrogen and phasphorus, by themselves orin combination with othernutrients, shalf 6e maintained at levels below thase which stimulate algae and emergent p/ant growth. Threshold total phasphorus (P) concentrations sha0 not exceed 0.05 mg/1 in any stream at the point where it enters any standing body of water, nor 0.025 mg/I in any standing body ot water. A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/1 total P. These values are not to be exceeded more than 10% of the time unless studies of the specifrc wate~ body in question clearly show that water quality objective changes are permissible and changes are approved by the Regionffi Board. Analogous threshold values have not been sef for nitrogen compounds; however, natural ratias ofnftrogen to phasphorus are to be detertnined bysurve171ance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used. Inland surhace waters shall not contain biastimufatory substances in concantrations in excess ofthenumerical objectives described in Table 3-2. Note - Certain exceptions to the above water quality objectives are described in Chapter 4 in the sections titled Discharges to Coastal Lagoons from Pilot Water Reciamation Projects and Discharges to Inland Surface Waters. BORON Boron occurs as sodium borate (borax) or as calcium borate (colemanite) in mineral deposits ~ and natural waters of southem California. Boron is not considered harmfui. in drinking waters in concentrations up to 30 mg/I. Boron is ' WATER QUALI7Y OBJECTIVES 3-5 September 8. 1994 3a° '' a~ essential elementforthe growth of plants butthere is no evidence that it is required by animals. Naturally , occurring concentrations of boron shouid have no effect on aquatic life. Concentrations of boron in irrigation waters in excess of 0.75 mg/I may be deleterious to sensitive plants such as citrus. The maximum safe concentration of boron for even the mosttolerant plants is about 4.0 mg/I. The United States Environmental Protection Agency (US EPA) has established a water quality criterion for boron of 0.75 mg/I for long term- term irrigation on sensitive crops. This criterion is found in Quality Cnteria for Water, i986 - the "Gold Book'. Additional information regarding boron concentrations in irrigation waters is presented in Table 3-1. , Water Quality Objectives for Boron: INand surface waters shall not contain boron in ,concentratrons in excess of the numerical objectives described in Table 3-2. Ground watersshallnotcontainboroninconcantrations in excess of the numerical objectives described in Table 3-3. CHLORIDES ' Most waters contain chlorides because they are present in many rock types and are very soluble in water. Chiorides may be of natural mineral origin or derived 'from (a) seawater intrusion of ground water supplies, (b) salts spread on fields for agricultural purposes, (c) human or animal sewage or (d) industrial wastes. Chiorides may impart a salty taste to drinking water in ~concentrations between 100- 700 mg/I. The secondary drinking water standard for chlorides is 500 mg/I. Elevated chloride concentrations in waters used for industrial process and supply can significantly increase ~the corrosion rate of steel and aluminum. High chloride concentrations can be toxic to plant life. A safe concentration of chloride for irrigation water is considered to be in the range of 100 - 140 mg/I. ,Irrigation with water containing 140 - 350 mg/I of chloride may cause siight to moderate plant injury. Additionai information regarding chloride concentrations in irrigation waters is presented in Table 3-1. 'Water QuaUty Objectlves for ChloAdes: Inland surtace waters shall not contain chlorides in 'concentrations in excess of the numerical objectives described in Table 3-2. Ground waters shall not contain chlorides in ,concentrations in excess of the numerical objectives described in Ta6le 3-3. COLOR ,Color in water may arise naturalty, such as from minerals, plant matter, or algae, or may be caused by industriai poliutants. Color is primarily an aesthetic 'consideration, although itcan discolorclothes and food. The secondary drinking water standard for color is 15 color units. ' Water Quality Objectives for Co/or: Waters shall be free of coloration tha[ causes nuisance or adversely a/iects beneficial uses. The natural color of fish, she/l~sh or other resources in inland surface waters, coastal lagoon or bay and esiuary shall not 6e impaired. Inland surface waters shall not contain color in concentrations in excess of the numerical objecfives described in Table 3-2. G~ound waters shallnot contain colorin concentrations in excess of the numerical objectives described in Table 3-3. DISSOLVED OXYGEN Adequate dissolved oxygen levels are vital for aquatic life. Depression of dissoived oxygen Ievels can lead to fish kilis and odors resufting • from anaerobic decomposition. Dissolved oxygen content in water is a function of water temperature and salinity. Water Qualiry Objective for Dfssolved Oxygen: Dissolved oxygen levels sflall not be less than 5.0 mg/1 in inland surface waters with designated MAR or WARM benefrcial uses or less than 6.0 mg/I in waters with designated COLD beneficia! uses. The annual mean dissolved oxygen concentration shall not be less than 7 mg/l more than lOq of the time. FLOATING MATER/AL Fioating materiai is an aesthetic nuisance as well as a substrate for algae and insect vectors. Water Ouallty Objective for Floating Material: Waters shall not contain floating material, including solids, liquids, foams, and scum in concentrations which cause nuisance or adversely aHect beneficial uses. FLUORIDE Fiuoride does not naturally occur in high concentrations in surface waters, but may occur in detrimental concentrations in ground waters. Fluoride, in sufficient quantities, can adversely affect waters used as industriai process or suppiy in food, beverages, and pharmaceutical industries. The presence of optimai concentrations of fluoride in drinking water supplies can reduce dentai decay, especially among children. However, fluoride concentrations in excess of approximately 1.0 mg/I can increase the risk of mottled enamel in children and dental fluorosis in adults: Water Quality 06jectives for Fluoride: Inland surface waters shall not contain fluoride in concentrations in excess of the numerical objectives described in Table 3-2. Ground waters shall not contain fluoride in concentretions in excess of fhe numerical objectives descrrbed in Table 3-3. ' WATER QUALITY OBJECTIVES 3-6 September 8, 1994 ~\ ' ' . . HYDROGEN /ON CONCENTRATION (pH) ' The hydrogen ion concentration of water is called °pH'. The acidity or alkalinity of water is measured by the pH factor. The pH scale ranges from t to 14, wfth 1 to 6.9 ' being acid, 7.1 to 74 being alkaline, and 7.0 being neutral. Ranges (pH) of 6.5 to 9.0 are considered harmiess. A change of one point on this scale represents a ten-fold increase in acidity or alkalinity. ' Many pollutants can alter the pH, raising or lowering it excessively. In some cases even small changes in pH can harm aquatic biota. The pH changes can after the chemicai form of certain constituents, thereby , increasing their bioavaiiability and toxicity. For example, a decrease in pH can result in an increase in dissolved metal concentrations. Ammonia, which is a major component of sewage discharges, can be ' completely safe at pH 7.0 and extremely toxic to fish at pH 8.5 for the same total ammonia concentration. Water Quality Objectives for pH: ' Changes in normal ambient pH /evels shall not exceed 0.2 unds in waters with designated marine (MAR), or estuarine (EST), or saline (SAL) beneflcial uses. ' Changes in norma! ambient pH /evels shall not exceed 0.5 units in lresh waters with designated cold freshwater habitat (COLD) or warm freshwater habitaf (WARM) beneficial uses. ' ln bays and estuaries the pH shall not be depressed below 7.0 nor raised above 9.0. , In inland surface waters the pH shall not be depressed be%w 6.5 ~or raised above 8.5. INORGANIC CHEMICAlS - PRIMARY , STANDARDS Water Quality Objective for pomestlc or Municipal , supply: Waters designated for use as domestic or municipal ' supply (MUIV) shall no~ contain concentrations of inorganic chemicals in excess of the maximum contaminant levels set iorth in Califomia Code of Regulations, T'~t/e 22, Table 64431-A of Secfion 64431 (lnorganic Chemicals) and Tab/e 64431-8 of Section ' 64431 (Fluonde) which are incorporated by reference into this pian. These incorporations by reference are prospective including future changes to the incorporated provisions as the changes take e/fect. , (See Tables 3-4 and 3-5.) ' ' ' ' WATER OUALITY OBJECTIVES 3-7 Table 3-4. Maximum Contaminant Levets for Inorganic Chemicals specifled in Table 64431-A ot Section 64431 of Title 22 of the California Code of Regulations as amended January 3. 1995. Chemicai Maximum Contaminant Level, mg/1 Aluminum ~. Antimon 0.006 Arsenic 0.05 Asbestos 7 MFL' Barium ~. Be Ilium p.~q Cadmium p,005 Chromium 0.05 nide 0.2 Merou p ~2 Nickel p ~ Nftrate as NO q5, Nitrate+Nitrite(sum as nitr en ~p, Nitrfte as nitr en ~, Selenium 0.05 Thallium 0.002 ' MFL = million fibers per iiter, MCL for fibers exceeding 10 um in length. September 8, 7994 ~~ ~ ,Table 3-5. Limiting and Optimum Concentratlons for Fiuoride specified in Table 6443~-B of Section 64431 of Title 22 of the Calitomia Code of Re ulations as amended Ja 3 1 ' ~ , 1 Annual Averege of Maximum Daily Air Temperature nua , 995. Fluoride Coneentration, mg/I Degrees Fahrenheit Degrees Celsius lower optimum upper MCL 53.7 and below 12.0 and below p,g ~ 2 ~ ~ 2 4 53.8 to 58.3 12.1 to 14.6 0.8 1, 7 ~ 5 p p 58.4 to 63.8 14.7 to 17.6 0.8 1.0 1.3 2.0 63.9 to 70.6 17.7 to 21.4 p,7 p,g ~ 2 1 8 70.7 to 792 21.5 to 26.2 0.7 0.8 1.0 1.6 79.3 to 90.5 26.3 to 32.5 0.6 0.7 0.8 1.4 IRON 'Iron may be present in water due to natural origin, corrosion of inetaliic iron and its alloys by water in the presence of oxygen, and industriai waste discharges 'containing iron. Iron is u~desirable in domestic water supplies because it causes unpleasant tastes, deposits on food during cooking, stains and discolors laundry and plumbing fixtures. The secondary drinking water ,standard for iron is 0.3 mg/I. . Water Quallty ObJecHves for Iron: Inland surface waters shall not contain iron in concentrations in excess of the numerical objectives described in Table 3-2. Ground waters shall not contain iron in concentrations in excess of the numerical objectives described in Table 3-3. 'MANGANESE Manganese is undesirable in domestic water supplies ecause it causes unpleasant tastes, deposits on food uring cooking, stai~s and discolors laundry and lumbing fixtures, and foste~s the growth of some microorganisms in reservoirs, fiiters, and distribution systems. The secondary drinking water standard for ~anganese is 0.05 mg/I. Water pua/lty ObJectives for Manganese: ~nland surface waters shall not contain manganese in oncent~ations in excess of the numerical objectives described in Table 3-2. ~Ground waters shall not contain manganese in oncentrations in excess of the numerical objectives descri6ed in Table 3-3. ' t WATER QUALITY OBJECTIVES METHYLENF BLUE - ACTIVATED SUBSTANCES (MBAS) The MBAS test measures the presence of anionic surfactant (commercial detergent) in water. Positive test results can be used to indicate the presence of domestic wastewater. The secondary drinking water standard for MBAS is 0.5 mg/I. Water Ouality Objecilves for MBAS: Inland surface waters shall not contain MBAS in concentrations in excess of the numerical objectives descnbed in Table 3-2. Ground waters shall not contain MBAS in concentrations in excess of the numerical objectives described in Table 3-3. NITRATE High nitrate concentrations in domestic water supplies can be toxic to human I'rfe. Infants are particulariy susceptible and may develop methemoglobinemia (biue baby syndrome). The primary drinking water scandard for nitrate as NO, is 45 mg/i. Water Quality Objectives for Nitrate: Inland surface waters shall not contain nitrafe (as NO~ in concentrations in excess of the numencal ob%ecfives descri6ed in Table 3-2. Ground wafers shall not contain nitrate (as NO~ in concentrations in excess of the numerical objectives described in Table 3-3. OIL AND GREASE Oil and grease can be present in water as a result of the discharge of treated wastes and the accidental or intentional dumping of wastes into sinks and storm drains. Oils and related materials have a high surface 3-6 September 8. 1994 ~ , tension and are not soluble in water, therefore forming ' a film on the waters surface. This film can result in nuisance conditions because of offensive odors and visual impacts. Oil and grease can coat birds and aquatic organisms, adversely affecting respiration ' and/or thermoregulation. Wate~ Quality 06JecHve for Oils, Grease, Waxes or other Mater/als: ' Waters shall not contain oils, greases, waxes, or other materials in concentrations which resulf in a visible film or coating on the surface of the water or on objects in , the water, or which cause nuisance or which othenvise adversely aNect beneBcia/ uses. ORGANIC CHEMICALS - PRIMARY , STANDARDS Water Qua/!ty ObJectlves: , Water designated for use as domestic or municipal supp/y (MUN) sha/l not contain concentrations of chemical consiRuents in excess of the maximum contaminant /evels specified in Califomia Code of ' Regulations, T'dle 22, Tab/e 64444-A of Section 64444 (OrganicChemicals) whichis incorporatedbyreference into this p/an. This incorporation by reference is prospective includirtg luture changes to the ' incaporated provisions as the changes take effect. ( S e e T a b l e 3- 6.) r ~ ~ ~ ~ ~ ~ ~ ~~ ' WATER QUALIIY O&IECTIVES 3-9 September 8, 1994 ~ ~ ~ Table 3-6. Maximum Contaminant Levels for Organic Chemicals specified in Table 6444•i-A of Section ' 64444 of Title 22 of the California Code of Re ulations as amended Janua 3, 1995. Chemical Maximum Contaminant Level, m /t I (a) Volatile Or anic Chemicals (VOCs) Benzene Q Q~~ ' Carbon Tetrachloride 0.0005 7 ,2-Dich lorohenzene 0.6~ I 1,4 Dichlorobenzene 0.005 1,~-Dichloroethane p 0O5 1,2-Dichloroethane 0.0005 ' 7,1-Dichloroeth Ine p_aps cis-1,2-Dichloroeth lene 0.006 1 trans-l,2-Dichloroeth lene 0.01 ~ Dichloromethane 0.005 1,2-Dichloro ro ane 0.005 ~ 1,3-Dichloro ro ene 0.0005 Eth Ibenzene Q ~ I Monochlorobenzene p,p~ S rene ~ ~ 7.1.2,2-Tetrachloroethane 0.001 I Tetrachloroeth ene 0.005 Tol uene O. 7 5 I 1,2,4Trichlorobenzene 0.07 ~.7.1-Trichloroethane ~ p,200 7,1,2-Trichloroethane 0.005 Trichloroeth lene 0.005 Trichlorofluoromethane p, ~ 5 1.1,2-Triehloro-7,2,2-Trifluoroetha e 7.2 Vin 1 Chloride 0.0005 X lenes ~ 75. (b) Non-Volatile Synthetic Organic Chemicals (SOCs) Alachlor 0.002 Atrazine 0.003 Bentazon 0.0'I 8 ' Chemical Maximum Contaminan t Levei, m /I Benzo(a) rene 0.0002 Carbofu ra n 0.07 8 Chlordane 0.0001 2.4D 0.07 Dala on p 2 1,2-Dibromon-3-chioro ro a e 0.0002 Di(2-eth Ihe I)adi ate 0.4 Di(2-eth Ihexq hthalate 0.004 Dinoseb 0.007 Di uat ~ O2 Endothall p ~ Endrin 0.002 Eth lene Dibromide ~ 0.0000 GI hosate p.~ He tachlor 0.0000 He tachlor E xide 0.0000 Hexachiorobenzena 0.001 Hexachloro clo ntadiene 0.05 lindane 0.0002 Metho chlor 0.04 Molinate 0.02 Oxam I ~ 2 Pentachloro henol - 0.007 Picloram 0.5 Pol chlorinated Bi hen Is 0.0005 Simazine p,ppq Thiobencarb 0.07 Toxaphene 0.003 2,3.7,8-TCDD (Dioxin) 3x10~ 2,4,5-TP Silvex 0.05 'MCL is for either a single isomer or the sum of the isomers. ' WATER ~UALIIY OBJECTIVES 3-10 September 8, 7994 ~ , ' Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of toluene in excess of 1 mgA. ' The Unfted States Environmental Protection Agency established a maximum co~taminant level for toluene of 1 mg/I in drinking water in TRIe 40, Code of Federal ' Regulations, Part 14f.61, (40 CFR 141.61), EPA Nationa! Primary Drinking Water Regulations (40 CFR 141.61 as revised 40 FR 59570, Juty 1, 1991), , ' , ' ' , , , ' ' , ~ ' t PERCENT SOD/UM AND ADJUSTED SOD/UM ADSORPT/ON RAT/O Excess concentrations of sodium in irrigation water reduce soil permeability to water and air. The deterioration of sodium in irrigation water is cumulative and is accelerated by poor drainage. Table 3-1 shows concentration guide~ines for sodium, boron, chloride and other chem ical constituents present in irrigation waters. The specific water quality objective for sodium in the Basin Plan is expressed as percent sodium. Percent sodium is calculated as follows: % Na = Na x 100% Na+Ca+Mg+K where sodium (Na), Calcium (Ca), Magnesium (Mg) and Potassium (K) are expressed in milliequivalent per liter (me/I). The percent sodium objective was developed for the protection of agricuttural uses from the potential hazard due to sodium in irrigation waters. The value of 60% sodium is based upon WaterQuality Criteria, by McKee and Wolf, 1963. McKee and Wolf note that because of all the variables involved, the class'rfication of waters for irrigation use must be somewhat arbitrary and the limits set cannot be too rigid. The three general classifications of irrigation waters are: CLASS 9'oSODIUM DESCRIPTION <30 - 60 % Excellent to good, or suitable for most plants under most conditions. 30 - 75 % Good to injurious, harmful to some plants under conditions of soii, climate and practices. III >70 - 75 % Injurious to unsatisfactory, unsuitable under most conditions. Since the pubiication of the percent sodium criteria, technical research has resulted in the development of more applicable criteria for addressing the potential sodium hazard in irrigation water. The sodium adsorption ratio (SAR) and adjusted sodium adsorption ratios (Adj. SAR) are measures of the potential hazard in soils due to sodium. SAR and Adj. SAR are similar to percent sodium in that their calculated values provide an indication of a soil's potential for permeabi~ity and potential aeration problems. However, by taking into consideration the soil's sodicity and the exchange phases between Ca, Na and Mg, the SAR and Adj. SAR predict potential sodium build up in soils. The Adj. SAR calculation further takes into account the effects of carbonate and bicarbonate ion concentrations of a soil. Adj. SAR is ' WATER QUALITY O&IECTIVES 3-11 September 8, 799a ~ ~~ the most common method for determining sodium hazard in irrigation water at the present time. , The calculation for SAfl is as follows: SAR = . ~ Na ' ~ Ca+M 2 where Na, Ca and Mg are in me/I. 'The calculation for Adj. SAR is as foilows: Adj. SAR - Na , ~(Ca.+Ma1 2 where Na and Mg are in me/I. 'Ca, is a modified Ca value, calculated using the Suarez table (Tabte 3-3, contained in Irrigation with Reclaimed Municipal Wastewater, A Guidance Manual, Califomia State Water Resources Control Board, Report Number 84-t, July 1984). Ca„ takes into account salinity (EC ), the HCO,/CO ratio (meA) and the estimated paR al pressure of CUZ in the top few millimeters of the soil ,(Pcoz = 0.0007 atmospheres). Water Quality Objecflves for Sodlum: lnland surface waters shall not contain perceni sodium in excess of the numerical objectives described in Table 3-2. 'Ground waters shall not contain percent sodium in excess of the numerical objectives described in Table 3-3. In some cases, adjusted sodium adsorption ratio may be a better indicator of the poteniial sodium hazard in irrigation water than percent sodium. The Regional Board F~cecutive Officer may authorize the use of ~adiusted sodium absorption ratio instead of percent ~sodium to indicate the potential sodium hazard. In such cases, the adjusted sodium adsorption ratio shaU not exceed the slight to moderate range of values eferenced in Table 3-1 `Guidelines for Interpretation of Water Qualffy for )rrigation". PESTIClDES esticides can enter surface and ground waters directly hrough industrial process discharges, agricuitural discharge, spillage and iilegal dumping. Pesticides can Iso enter surtace and ground waters indirectly by rifting away from areas where pesticides are being sprayed, through surface runoff from treated fields, and by leaching or return flows from irrigation. Pesticides an concentrate in ptant or animal tissues and many are onsidered to be carcinogenic to humans. Although many pesticides are designed to deteriorate rapidly when exposed to suniight and air, they may persist for onths or years in water. alifomia Code of Regulations, Title 22, Table 64444-A of Section 64444 (Organic Chemicals) estabiishes ~aximum contaminant levels for pesticides in drinking water. (See water quality objective for Organic Chemicals). Water Quality Objectives for Pesticldes: No indivrdual pesticrde or combination ol pesticides shall be present in the watercolumn, sediments or6iota atconcentration(s) thatadverselyaffectbeneBcialuses. Pesticides shall not be present af levels which will bioaccumulate rn aquatrc organisms to levels which are harmlul to human health, wildlife or aquatic organisms. Water designated for use as domestic or municipa! supply (MUN) shall not contain concentrations of pestrcides in excess of the maximum contaminant levels specified in California Code of Regulations, T'dle 22, Table 64444-A of Section 64444 (Organic Chemicafs) which rs incorporated by referenca into this plan. This incorporation by reference is praspective mcluding future changes to the incorporated provisions as the changes take effecL (See Tabfe 3-6) PHENOUC COMPOUNDS Phenolic compounds are in widespread use as industrialandagriculturalchemicalintermediatesforthe preparation of other chemicais. These or~anic compounds are byproducts of petroleum refining, tanning, and textile, dye, a~d resin manufacturing. Low concentrations cause taste and odor problems in water, higher concentrations can kill aquatic i'rfe and humans. Phenol is occasionaliy referred to as 'carbolic acid. WaterOuality Obiectives forPhenollc Compounds: Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of phenolics in excess of 1.0 ug/1. Shouid there be any conflict between this limit and those described under the Organic Chemicals objective the more stringent standards shali apply at all times. ~~~ RADIOACT/V/TY r Water Quality ObJecUve tor RadloacUvlty: Aadionuclides shall not be present in concentrations that are deleterious to human, plant, animal, or aquatic life nor that result in the accumulation of radionuclides in the food web to an extent that presenfs a hazard to human, plant, animal or aquatic life. Water Qua/ity Objective foi Rad/onuclides: Waters designated for use as domestic or municipa! supply (MUN) shall not contain concentrations of radionuclides in excess of the levels specified in Section 64441 of Title 22 of the Califomia Code of Regulations (Natural Radioactivity) and the maximum contaminant levels specrfied in Table 4 of Section 64443 of Title 22 of the Califomia Code of Regulations (Man-Made Radioactivity), which are both rncorporated by reference into this plan. These inco~porations by reference are prospective including future changes to the incorporated provisions as the changes take effect. (See Table 3-7.) , WATER QUALIN OB,IECTIVES 3-72 September B, 7994 ~1 ,' ., ' ' ' , , ' ~ ' ~ , , ' ' '~ ' ~ ~ ' Table 3-7. Max(mum Contaminant Levels (or Radloactivity specHied in Table 4 of Section 64443 of Title 22 of the Calftomla Code ot Regulations as amended January 3. 1995. Constituent Maxlmum Contami~ant Level, CUI Combined Radium- g 226 and Radium-228 Gross Alpha Particle 15 ACtIVi~ (induding Radium- 226 but enduding Radon and Uranium Tritium 20,000 Strontium-90 g Gross Beta Particle 5p Act' ' Uranium 20 (pCUI = picocuries per liter = curies x 10'12 per liter ) WATEq QUALITY 08.lECTIVES SECONDARY DRINK/NG WATER STANDARDS Water Quallty ObJecHve for pomest/c or Munlcipa/ Supply Water. Water designated foi use as domestic or municipal supply (MUN) shall not contain concenhations of chemical constituents in excess of the maximum contaminant levels specfied in Table 64449-A of Section 64449 of T'd!e 22 of the Califomia Code of Regulatlons (SecondaryMaximumContaminant levels, ConsumerAcceptance Limits) which is incoiporated by reference into this p/an. This incorporation by reference is prospective including luture changes to the incorporated provisions as the changes take effecf. (See Table 3-8.J 3-13 September8. t994 ~$ ' ' , , , ' , ' ' ~ r ' ' , , ' ~ ' At no time or place shal! the temperature of any COLD water be increased more than 5°F above the natural receiving water temperature. TOTAL D/SSOLVED SOLIDS Dissolved solids in natural waters may consist of carbonates, bicarbonates, chlorides, sulfates, phosphates, nitrates, magnesium, sodium, iron, manganese and othersubstances. The recommended secondary drinking water standard for total dissolved solids is 500 mg/i with a upper limit of 1000 mg/I due to taste considerations. High total dissolved solids concentrations in irrigation waters can be deleterious to plants directiy, or indirectly through adverse effects on soil permeabiiity. A classification of irrigation waters with respect to total dissoived solids concentration is described in Table 3-1. WaterQuality Objectives forTotal Dlssolved SoOds: Inland surtace waters shall not corttain tota! dissolved solids in concentrations in excess of the numerical objectrves described in Tab/e 3-2. Ground waters shall not contain total dissolved solids rn concentrations in excess of the numerica! objectives described in Table 3-3. TOXICITY Toxicity is the adverse response of organisms to chemicals or physical agents. Water Quallty ObjecUves for Toxlcity: A!I waters shad be maintained free of toxic subsfances in concentrations that are toxic to, or that produce deMmental physiological responses in human, planf, animal, or aquaf~c life. Compliance w8h this objective will be determined by use of indicator organisms, analyses of species divers~'ty populafion density; growth anomalies, bioassays ofappropriateduration, o~ otherappropriate methods as specified by the Regional Board. , The survivaf of aquatic life in surface waters subjected to a waste discharge or other controflable water quality facfors, shall not be less than that for the same water body in areas una/lected by the waste discharge or, when necessary, for other contro! water that is consistent with requirements specified in US EPA, State Water Resources Control Board o~ other protocol authorized by the Regional Board. As a minimum, compliance with this objective as stated in the previous sentence shall be evaluated with a 96-hour acute bioassay. In addition, effluent Irmits based upon acute bioassays of effluents wilJ be prescribed where appropriate, additional numerrcal receiving water objectives for specific toxicants will be established as sufficient data become available, and source con[rof of toxic subsfances will be encouraged. TOX/C POLLUTANTS Federal Register, Volume 57, Number 246 amended Title 40, Code of Federal Regulations, Part 731.36 (40 CFR 131.36) and established numeric criteria for a limited number ot priority toxic pollutants for inland surtace waters and esFuaries in California. US EPA promuigated these criteria on December 22, 1992, to bring Califomia into full compliance with Section 303(c)(2)(8) of the Clean Water Act. California is not currently in full compliance with Section 303(c)(2)(B) of the Clean W ater Act due to the invalidation of the Water Quality Control Plan for Inland Surtace Waters of California and the Water Quality Control Plan for Enclosed Bays and Estuaries of California. However, the criteria established in 57 FR 60848 (December 22, 1992) (specificaily pages 60920 - 60921) are still applicable to surface waters in the Region. Water Quality Objecfives for Toxfc Pollutants: Inland surface waters, enclosed bays, and estuaries shall not contain toxic pollutants in excess of the numerical objectives applicable to Califomia specified in 40 CFR 131.36 (§131.36 revised at 57 FR 60848, December22, 1992). TR/HALOMETHANES Chlorine is the dominant chemical agent used to disinfect treated water and wastewater. Trihalomethanes are formed when chlorine reacts with aquatic organic materiat found in water and wastewater. Trihalomethanes are a group of light weight chlorinated hydrocarbons which are suspected carcinogens. The US EPA has established a maximum contaminant level for total trihaiomethanes of 0.1 mg/I in T'dle 40, Code of. Federal Regulations, Part 141.12, (40 CFR 141.12), EPA National Primary Drinking Water Regulations (§141.12revisedat57FR31838,Ju1y17, 1992). Totai trihalomethanes are the sum of the concentrations of bromodichloromethane, dibromochioromethane, tribromomethane (bromoform) and trichioromethane (chloroform). The federal regulations on trihalomethanes are incorporated by reference into Califomia Code of Regulations, Title 22, Chapter 15, Articles 4.5, Sections 64439. Water Qoality Objectlve for Trihalomethanes: Waters designated for use as domesfic or municipa! supply (MUN) shall not contain concentrations of trihalomethanes in excess o/ the criteria set /orth in Califomia Code of Regulations, Tide 22, Section 64439 which is incorporated by reference into this plan. This incorporation by reference is prospective including future changes to Section 64439 as the changes take effect. TURBIDITY The turbidity of water is attributable to suspended and colloidal matter, the effect of which is to disturb clearness and diminish the penetration of light. High turbidity ievels can adverseiy affect the use of water for drinking. By intertering with the penetration of Iight, turbidity can adversely affect photosynihesis which aquatic organisms depend upon for survivai. High concentrations of particulate matter that produce turbidity can be directly lethal to aquatic life. ' WATER QUALI7Y 0&IECTNES 3-15 September 8, 1gg4 ~ ,. Water Quality Objecfives for Turbidity: , Waters shall be iree of changes in turbidity that cause nuisance or adversely affect beneficial uses. Inland surface waters shall not contain turbidity in excess of the numerical objectives described in Tabie 3-2. ' Ground waters shall not contain turbidiry in excess of the numencal objectives described in Table 3-3. 1 _` -~_~ y ' `t` , ~ The transparency of waters in lagoons and estuaries shall not be less than 509'0 of the depth at focafions ' where measurement is made by means of a standard Secchi disk, except where lesser transparency is caused by rainfall runoflfrom undisturbed natural areas and dredging projects conducted in conformance with 'wasie discharge requirements of the Regional Board. With these two exceptions, increases in tur6idity attributable to contro!lable wateiquality factors shall not ,exceed the foilowing limits: Natura/ Turbldltv Maximum increase 20% over natura! -50 NTU turbrdiry leve! 50-100NTU i0 NTU ~~eater than f00 NTU 10% over natural ~ turbidity level n addition, within San Diego Bay, the transparency of ay waters, insofar as it may be influenced by any ontrollable facior, either directly o~ through induced conditions, shall not be /ess than 8 feet in more than 20 ercent of the readings in any zone, as measured by a ~tandard Secchi disk. Wherever the water is less than 0 feet deep, the Secchi disk reading shall not be less than 80 percent of the depth in more than 20 percent of he readings in any zone. ~ATER QUAUTY OBJECTIVES ~F INLAND SURFACE WATERS peciTic numerical water quality objectives for iniand surface waters are presented by hydrologic area and ubarea and watershed in Table 3-2. ~he water quality objectives for inland surtace water designations described in this table correspond with the eneficial use designations previously described in hapter 2. W ater Quality Objective variations occur in ome of the hydrologic areas, subareas and stream ' WATER QUALITY O&IECTIVES 3-16 reaches. Water quality variations from the objectives may also occur within a given hydrologic area subarea or stream reach. Such locai variations wiil be evaluated when waste discharge requirements, NPDES permits, Cleanup and Abatement Orders, and Cease and Desist Orders are being developed for a given discharger. The omission of mineral objectives for some areas corresponds to the lack of beneficiai uses (AGR, MUN, IND) requiring such objectives. WATER QUALITY OBJECTIVES OF GROUND WATERS Specific numericai water quality objectives for ground waters are presented by hydroiogic area and subarea in Table 3-3. A footnote for some ground water basins is listed to show that some water qualiry objectives are considered tentative until detailed salt balance studies are conducted. In 7978 the Regional Board, in Resolution No. 78~, deleted water qualiiy objectives and beneficial uses for certain portions of basins 1.10, 1.20, 1.30, 1.40, 1.50, 2.10, 3.10, 4.10, 4.20, 4.30, 4.40, 4.50, 4.60, 5.10, 6.10, 7.10, and 11.10. Table footnotes are included to identify these basins. The Regional Board elected to delete beneficiai uses in portions of these basins, where the uses of ground water were marginai or nonexistent, to promote wastewater reclamation by sewage treatment plants. The deletion of beneficial uses in these areas was based upon a determination that the loss of ground water suppiies was ouriveighed by the long-term increase in wastewater reclamation made possible by allowing reclaimed water discharges which are high in total dissoived solids. It is the Regionai Board's intent to protect the water quality in these basins under the terms of State Board Resolution No. 68-16. For purposes of intrusion barrier formation or ground water recharge, the water quaiity objective qual'rfications footnoted in Table 3-3 allow, with approval of the Regional Board, discharge of reclaimed water in areas of equal or poorer ground water quality. Relatively poor quality water could also be used for intrusion barrier formation along the coast. WATER QUALITY CRITER/A The literature contains many different water quality criteria designed to protect specific beneficia~ uses of water. A summary of the specific numerical water quality criteria considered by the Regionai Board for designation as water quafity objectives is described in Appendix C. The water quality criteria described in Appendix C are not enforceabie water quality objectives. The purpose of presenting the information summarized in these tables is to allow interested persons to compare available water quality criteria to the specific water quality objectives designated by the Regional Board described earlier in this Chapter. September 8, 7994 d~ ~ l' REFERENCES California Fertilizer Association. 1985. Westem Fertilizer Handbook. Seventh Edition. The Interstate ' Printers & Publishers, inc. Danviile, Illinois. 288pp. California Regional Water Quality Control Board, Central Vatley Region. 1993. A Compilation of Water I , Qualiry Goais. California Regional W ater Quality Controi Board, San Diego Region. 7975. Comprehensive Water Quality ' Control Plan Report for the San Diego Basin (9). James M. Montgomery, Consulting Engineers, Inc. Califomia State W ater Resources Control Board. 1963. ' Water Quality Criteria. Second Edition. Edited by J.E. McKee and H.W. Wolf. Publication No. 3-A. 548pp. State of California. 1979. The Cal'rfomia Water Atlas. 117pp. 1 U.S. Environmental Protection Agency. July 1976. Quality Criteria for Water. U.S.G.P.O. Stxk No. 055- , 001-01049-4. 256pp. U.S. Environmental Protection Agency. 1980. Ambient Water Quality Criteria for Phenol. EPA 440/5-86-066. ' Office of Regulations and Standards. Washington, D.C. U.S. Environmental Protection Agency. 1986. Quality Criteria for Water. EPA 440/5-86-001. Office of ~ /NDEX ~ SiCHAPTE9R 3 c ~ Ocean Plan ............................... 4 ThermalPlan .............................. 4 Water qualitycrfteria ........................ 2 W ater Quality Objective ' agriculturalsuPP~Y ....................... 5 bacterio log ical . . . . . . . . . . . . . . . . . . . . . . . . . . 5 bays and estuaries ...... ........ 6 biostimulatory substances . . . . . . . . . . . . . . . . . 6 ' boron ................................. ~ chlorides .............................. coiiform ............................... 6 color .................................. 7 ' contactrecreation ....................... 5 definition ot . . . . . . . , ~ designation of, under C~ean Water Act ....... 2 designation of, under Porter-Cologne . . . . . . . . t ' dissolved oxygen . . . . . . . . . . . . . . . . . . . . . . 4, 8 fioating material . . . . . . . . . . . . . . . . . . . . . . . . . 8 fluoride ................................ 8 inorganic chemicais primary standards . . . . . . . . . . . . . . . . . . . . 8 ' iron ................ .................. 9 manganese .. , g methylene blue-activated substances . . . . . . . . 9 nitrate ...:............................ 70 ~ non-contactrecreation .................... 5 oiland grease ......................... 10 ' organic chemicals primary standards . . . . . . . . . . . . . . . . 10 ' ... pesticides ............................. 13 pH .................................. 4,8 phenolic compounds . . . . . . : . . . . . . . . . . . . . 13 radioactivity ....................... .... 13 sediment ......................... .... 14 shellfish harvest . . . . . ... . . . . . . . . . . . . . . . . . . 5 sodium ........................... .... 12 sulphate .......................... .... 15 suspended and settleable solids . . . . . . . . . . . 14 taste and odor ...................... ... 15 temperature ........................ ... 15 total dissoNed solids . . . . . . . . . . . . . . . . . . . . 15 toxiciiy ............................ ... 15 turbidity .............................. 16 un-ionized ammonia . . . . . . . . . . . . . . . . . . . . . 5 '; WATER QUALITY OBJECTIVES 3-17 Septembe~ 8. 1994 ~`