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HomeMy WebLinkAboutSDP 01-01B; Biltmore; Site Development Plan (SDP) (5)STORM WATER MANAGEMENT PLAN Biltmore Pacifica Lot G, Rancho Agua Hedionda, Map No. 823 R.O.S. 5715 (Portion of Description 3) SDP /CDP Prepared For: Biltmore Holdings 8475 E. Hartford Drive, Suite 201 Scottsdale, Arizona 85255 Lang Engineering Company 561 Saxony Place, Suite lOlB Encinitas, CA 92024 ©2005 March 8, 2005 INTRODUCTION 1. Project Description , 1.1. Topography and Land Use , 1.2. Hydrologic Unit Contribution 2. WATER QUALITY ENVIRONMENT 2.1 Beneficial Uses 2.1.1. Inland Surface Waters 2.1.2. Groundwater 3. CHARACTERIZATION OF PROJECT RUNOFF 3.1. Existing and Post-Construction Drainage 3.2. Post-Construction Expected Discharges 3.3. Soil Characteristics 4. MITIGATION MEASURES TO PROTECT WATER QUALITY 4.1. Construction BMPs 4.2. Post-construction BMPs 4.2.1. Site Design BMPs 4.2.2. Source Control BMPs 4.2.3. Treatment Control BMPs 4.2.3.1 Bio-Filters 4.2.3.1.1 Appropriate Applications and Siting Constraints. 5. OERATION AND MAINTENANCE PROGRAM 5.1. Bio-Filters 6. SUMMARY/CONCLUSIONS ATTACHMENTS A. Location Map B. Project Map C. BMP Map D. BMP Data Sheets INTRODUCTION The Stormwater Management Plan (SWMP) is required under the County of San Diego Watershed Protection, Stormwater Management, and Discharge Control Ordinance (section 67.817). The purpose of this SWMP is to address the water quality impacts from the proposed improvements on Lot G, Rancho Agua Hedionda, Map No. 823 R.O.S. 5715 (Portion of Description 3). Best Management Practices (BMPs) will be utilized to provide a long-term solution to water quality. This SWMP is also intended to ensure the effectiveness of the BMPs through proper maintenance that is based on long-term fiscal planning. The SWMP is subject to revisions as needed by the engineer. 1.0 PROJECT DESCRIPTION The 13.385 acre project is located approximately 400' east of the southeast corner of the intersection of Aviara Parkway and Palomar Airport Road in the City of Carlsbad, California. The project will consist of a three story, 75,000 s.f. commercial office building and associated on grade parking. Of the total site area of 13.39 acres, approximately 7.6 acres is developable due to site constraints. Topography and Land Use The approximate 7.6 acre developable portion of the site was previously graded under the County of San Diego grading permit drawing L-7945 and has since remained undeveloped. The site is fairly level and slopes generally from north to south towards the creek. The surrounding uses are similar to the proposed project; a multi-story commercial office building is located west of the project along Palomar Airport Road and a completed apartment project located southwest of the site along Laurel Tree Lane. Across Palomar Airport Road is the acreage currently under development to construct the Carlsbad Municipal Golf Course. 1.2 Hydrologic Unit Contribution The Ocean Ridge at Carlsbad Ranch project is located within the Carlsbad hydrologic unit (4.40). The project drains southerly from Palomar Airport Road and discharges into the Canyon de las Encinas which runs westerly to the Pacific Ocean. WATER QUALITY ENVIRONMENT 2.1 Beneficial Uses The existing and potential beneficial uses for the hydrologic unit are included in Tables 1.1 and 1.2. These tables have been extracted from the Water Quality Control Plan for the San Diego Basin. REC1 - Contact Recreation: Includes uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs. REC2 - Non-Contact Recreation: Includes the uses of water for recreational involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, picnicking, sunbathing, hiking. camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. WARM - Warm Freshwater Habitat: Includes uses of water that support warm water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish or wildlife, including invertebrates. WILD - Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including, but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water and food sources. 2.1.1 Inland Surface Waters Inland Surface waters have the following beneficial uses as shown on table 1.1 Table 1.1 Beneficial Uses for Inland Surface Waters Hydrologic Unit Number Mun Red Rec2 Warm Wild 4.40 * 0 x x x * Excepted from Municipal X Existing Beneficial Use 0 Potential Beneficial Use 2.1.2 Groundwater Groundwater beneficial uses includes agricultural and potentially municipal and industrial. Table 1.2 Beneficial Uses for Groundwater Hydrologic Unit Number Mun 4.40 x Excepted from Municipal 3.0 CHARACTERIZATION OF PROJECT RUNOFF 3.1 Existing and Post-Construction Drainage The proposed improvements will not significantly alter drainage patterns within the project site. Runoff generate from the project site will be collected in a number of on-site inlets. In addition, two public storm drainage pipes (18" & 30") presently discharge from the Palomar Airport Road right-of-way into the project site. These two pipes will be extended to the south, new inlets will be constructed to collect on-site storm drainage and all drainage will ultimately discharge to a 600' long bio-swale that will effectively treat both the off-site public storm water as well as the private on-site storm water prior to entering the existing creek. As the site is currently undeveloped, the actual runoff from the project site will increase due to the amount of impervious surface that will be constructed. However, the existing creek traverses the property and the post developed flows will discharge directly into the creek after flowing through the proposed bio-swale. 3.2 Post-Construction Expected Discharges There are no sampling data available for the existing site condition. In addition, the project is not expected to generate significant amounts of non-visible pollutants. However, the following constituents are commonly found on similar developments and could affect water quality: • Sediment discharge due to construction activities and post-construction areas left bare. • Nutrients from fertilizers • Trash and debris deposited in drain inlets. • Hydrocarbons from paved areas. 3.3 Soil Characteristics A soils investigation has been performed by Geocon, Inc., dated February 7, 2001, Project No. 06480-32-01 and the following is a brief description of the existing soil conditions as stated in this report. The report should be read in its entirety to determine the full soils condition. An excerpt from this report are as follows: ..."Two surficial soil types and orie geologic formation were encountered during tfie field investigation. The surficial deposits consist of undocumented fill, and alluvium. The formational units consists of the Santiago Formation. Each of the surficial soil types and the geologic formation encountered is described below in order of increasing age."... ... "The undocumented fill typically consisted of medium dense, clayey and silty, fine-to medium- grained sand and sandy clay. Chunks of asphalt concrete and Portland cement concrete, as well as other debris, were observed on the surface of the fill during the site investigation; however none were encountered within the borings or soundings suggesting that the debris is limited in extent. Portions of the undocumented fill will require remedial grading"... ... "Alluvial soils appear to underlie all but the northwest corner of the development area. Based upon exploratory borings and soundings, the alluvium is at least 55 feet thick and consists of moist to saturated, firm to very stiff, silty and fine to medium grained sandy clay with lenses of loose to medium dense, fine to medium grained sand with varying amounts of silt."... ..."The Tertiary-age Santiago Formation was found to underlie the surficial soils in all of the borings and consists of medium dense to very dense, massive, sandstone with some stiff claystone. The Sanitago Formation generally exhibits adequate bearing characteristics, but is not anticipated to impact the project due to its depth beneath the alluviuim"... 4.0 MITIGATION MEASURES TO PROTECT WATER QUALITY To address water quality for the project, BMPs will be implemented during construction and post-construction. 4.1 Construction BMPs Construction BMPs have been designed and located on the Grading Plan Construction Documents. The implementation of these construction BMPs are described in more detail within the Storm Water Pollution Prevention Plan (SWPPP) that has been prepared for this project. The following BMP items are proposed for this project: • Silt Fence (SE-1) • Gravel Bag Berm (SE-6) • Street Sweeping and Vacuuming (SE-7) • Sandbag Barrier (SE-8) • Storm Drain Inlet Protection (SE-10) • Material Delivery and Storage (WM-1) • Stockpile Management (WM-3) • Spill Prevention and Control (WM-4) • Solid Waste Management (WM-5) • Concrete Waste Management (WM-8) • Stabilized Construction Entrance/Exit (TC-1) • Dewatering Operations (NS-2) • Vehicle and Equipment Maintenance (NS-10) • Entrance/Outlet Tire Wash (TC-3) Construction BMPs for this project will be selected, constructed, and maintained so as to comply with all applicable ordinances and guidance documents. 4.2 Post-construction BMPs Pollutants of concern as noted in section 3 will be addressed through three types of BMPs. These types of BMPs are site design, source control and treatment control. 4.2.1 Site Design BMPs Typical of projects of this type, multi-story office buildings, the site will included a significant amount of impervious surfaces, including rooftop, parking lot and hardscape. During the site design process, the project was oriented such that the 600' bio-swale could be constructed in such a location as to allow the treatment of not only post development runoff generated on site but the off-site runoff presently discharging from the Palomar Airport Road right of way. Runoff from both the public right of way as well as the on-site development will be collected in two separate storm drainage systems and enter the proposed bio-swale at both the east and west ends. Runoff will then be treated as it flows to a common discharge point located midway along the bio-swale. The overall site design and the development guidelines has created large landscape areas both along the Palomar Airport Road right of way as well as along the northern edge of the existing creek. The large areas will allow significant landscaping to be installed. Landscaping of the slopes and common areas are incorporated into the plans and will consist of both native and non-native plants. The goal is to achieve plant establishment expeditiously to reduce erosion. The irrigation system for these landscaped areas will be monitored to reduce over irrigation. Source Control BMPs Source control BMPs will consist of measures to prevent polluted runoff. This program will include an educational component provided to the owner and facility operator who will receive a set of brochures developed by the County's Environmental Health Department. These will include the following: • Stormwater Runoff Pollution Fact Sheet • Stormwater Pollution Prevention Yard Work (Landscaping, Gardening, Pest Control) In addition, storm drain inlets will be stenciled with a message warning citizens not to dump pollutants into the drains. 4.2.2 Treatment Control BMPs The following treatment control BMPs will be implemented to address water quality: • Bio-Filters Placements ofthe BMP is noted on the project plan (Attachment 0) 4.2.3.1 Bio-Filters Bio-filtration swales are vegetated channels that receive directed flow and convey storm water. Bio-filtration strips, also known as vegetated buffer strips, are vegetated sections of land over which storm water flows as overland sheet flow. A schematic illustration of bio-filter is shown in Figure 3.3.1. Pollutants are removed by filtration through the grass, sedimentation, adsorption to soil particles, and infiltration through the soil. Swales and strips are mainly effective at removing debris and solid particles, although some dissolved constituents are removed by adsorption onto the soil. 4.2.3.1.1 Appropriate Applications and Siting Constraints: Swales and strips should be considered wherever site conditions and climate allow vegetation to be established and where flow velocities are not high enough to cause scour. Even where strips cannot be sited to accept directed sheet flow, vegetated areas provide treatment of rainfall and reduce the overall impervious surface. Factors Affecting Preliminary Design: Swales have two design goals: 1) maximize treatment, 2) provide adequate hydraulic function for flood routing, adequate drainage and scour prevention. Treatment is maximized by designing the flow of water through the swale to be as shallow and long as site constraints allow. No minimum dimensions are required for treatment purposes, as this could exclude swales from consideration at some sites. Swales should also be sized as a conveyance system calculated according to County procedures for flood routing and scour. To maximize treatment efficiency, strips should be designed to be as long (in the direction of flow) and as flat as the site will allow. No minimum lengths or maximum slopes are required for treatment purposes. The area to be used for the strip should be free of gullies or rills that can concentrate overland flow and cause erosion. Vegetation mixes appropriate for various climates and locations will be developed by District landscape staff. Table 3.3.1 summarizes preliminary design factors for bio-filtration. Plan View Vegetated Swale Cross Section Drain Outlet Vegetated Swale Figure 4.2.3.1 Example of Bio-filter Schematic Table 4.2.3.1: Summary Of Bio-filtration Design Factors (Strips And Swales) Description Applications/Siting Preliminary Design Factors Swales are vegetated channels that receive and convey storm water. Strips are vegetated buffer strips over which storm water flows as sheet flow. Treatment Mechanisms: • Filtration through the grass • Sedimentation • Adsorption to soil particles • Infiltration Pollutants removed: • Debris and solid particles • Some dissolved constituents Site conditions and climate allow vegetation to be established Flow velocities not high enough to cause scour Swales sized as a conveyance system (per County flood routing and scour procedures) Swales sized as a conveyance system (per County flood routing and scour procedures) Swale water depth as shallow as the site will permit Strips sized as long (in direction of flow) and flat as the site allows Strips should be free of gullies or rills No minimum dimensions or slope restrictions for treatment purposes Vegetation mix appropriate for climates and location 5.0 OPERATION AND MAINTENANCE PROGRAM The operation and maintenance requirement is as follows: 5.1 Bio-Filters The operational and maintenance needs of a Swale are: • Vegetation management to maintain adequate hydraulic functioning and to limit habitat for disease-carrying animals. • Animal and vector control. • Periodic sediment removal to optimize performance. • Trash, debris, grass trimmings, tree pruning, and leaf collection and removal to prevent obstruction of a Swale and monitoring equipment. • Removal of standing water, which may contribute to the development of aquatic plant communities or mosquito breeding areas. • Removal of graffiti. • Preventive maintenance on sampling, flow measurement, and associated BMP equipment and structures. • Erosion and structural maintenance to prevent the loss of soil and maintain the performance of the Swale. Inspection Frequency: The facility will be inspected and inspection visits will be completely documented: • Once a month at a minimum. • After every large storm (after every storm monitored or those storms with more than 0.50 inch of precipitation.) • On a weekly basis during extended periods of wet weather. Aesthetic and Functional Maintenance Aesthetic maintenance is important for public acceptance of stormwater facilities. Functional maintenance is important for performance and safety reasons. Both forms of maintenance will be combined into an overall Stormwater Management System Maintenance. Aesthetic Maintenance The following activities will be included in the aesthetic maintenance program: • Graffiti Removal. Graffiti will be removed in a timely manner to improve the appearance of a Swale and to discourage additional graffiti or other acts of vandalism. • Grass Trimming. Trimming of grass will be done on the Swale, around fences, at the inlet and outlet structures, and sampling structures. • Weed Control. Weeds will be removed through mechanical means. Herbicide will not be used because these chemicals may impact the water quality monitoring. Functional Maintenance Functional maintenance has two components: Preventive maintenance Corrective maintenance Preventive Maintenance: Preventive maintenance activities to be instituted at a Swale are: • Grass Mowing. Vegetation seed mix within the Swale is designed to be kept short to maintain adequate hydraulic functioning and to limit the development of faunal habitats. • Trash and Debris. During each inspection and maintenance visit to the site, debris and trash removal will be conducted to reduce the potential for inlet and outlet structures and other components from becoming clogged and inoperable during storm events. • Sediment Removal. Sediment accumulation, as part of the operation and maintenance program at a Swale, will be monitored once a month during the dry season, after every large storm (0.50 inch), and monthly during the wet season. Specifically, if sediment reaches a level at or near plant height, or could interfere with flow or operation, the sediment will be removed. If accumulation of debris or sediment is determined to be the cause of decline in design performance, prompt action (i.e., within ten working days) will be taken to restore the Swale to design performance standards. Actions will include using additional fill and vegetation and/or removing accumulated sediment to correct channeling or ponding. Characterization and Appropriate disposal of sediment will comply with applicable local, county, state, or federal requirements. The swale will be regraded, if the flow gradient has changed, and then replanted with sod. • Removal of Standing Water. Standing water must be removed if it contributes to the development of aquatic plant communities or mosquito breeding areas. • Mechanical and Electronic Components. Regularly scheduled maintenance will be performed on fences, gates, locks, and sampling and monitoring equipment in accordance with the manufacturers' recommendations. Electronic and mechanical components will be operated during each maintenance inspection to assure continued performance. • Fertilization and Irrigation. The vegetation seed mix has been designed so that fertilization and irrigation is not necessary. Fertilizers and irrigation will not be used to maintain the vegetation. • Elimination of Mosquito Breeding Habitats. The most effective mosquito control program is one that eliminates potential breeding habitats. Corrective Maintenance: Corrective maintenance is required on an emergency or non-routine basis to correct problems and to restore the intended operation and safe function of a Swale. Corrective maintenance activities include: • Removal of Debris and Sediment. Sediment, debris, and trash, which impede the hydraulic functioning of a Swale and prevent vegetative growth, will be removed and properly disposed. Temporary arrangements will be made for handling the sediments until a permanent arrangement is made. Vegetation will be re- established after sediment removal. • Structural Repairs. Once deemed necessary, repairs to structural components of a Swale and its inlet and outlet structures will be done within 10 working days. Qualified individuals (i.e., the designers or contractors) will conduct repairs where structural damage has occurred. • Embankment and Slope Repairs. Once deemed necessary, damage to the embankments and slopes of Swales will be repaired within 10 working days). • Erosion Repair. Where a reseeding program has been ineffective, or where other factors have created erosive conditions (i.e., pedestrian traffic, concentrated flow, etc.), corrective steps will be taken to prevent loss of soil and any subsequent danger to the performance of a Swale. There are a number of corrective actions than can be taken. These include erosion control blankets, riprap, sodding, or reduced flow through the area. Designers or contractors will be consulted to address erosion problems if the solution is not evident. • Fence Repair. Repair of fences will be done within 30 days to maintain the security of the site. • Elimination of Animal Burrows. Animal burrows will be filled and steps taken to remove the animals if burrowing problems continue to occur (filling and compacting). If the problem persists, vector control specialists will be consulted regarding removal steps. This consulting is necessary as the threat of rabies in some areas may necessitate the animals being destroyed rather than relocated. If the BMP performance is affected, abatement will begin. Othenwise, abatement will be performed annually in September. • General Facility Maintenance. In addition to the above elements of corrective maintenance, general corrective maintenance will address the overall facility and its associated components. If corrective maintenance is being done to one component, other components will be inspected to see if maintenance is needed. Maintenance Frequency The maintenance indicator document, included as Appendix B, lists the schedule of maintenance activities to be implemented at a Swale. Debris and Sediment Disposal Waste generated at Swales is ultimately the responsibility of the Developer, Biltmore Pacifica. Disposal of sediment, debris, and trash will comply with applicable local, county, state, and federal waste control programs. Hazardous Waste Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous wastes generated onsite will be handled and disposed of according to applicable local, state, and federal regulations. A solid or liquid waste is considered a hazardous waste if it exceeds the criteria listed in the CCR, Title 22, Article 11. 6.0 SUMMARY/CONCLUSIONS This SWMP has been prepared in accordance with the Watershed Protection, Stormwater Management, and Discharge Control Ordinance and the Stormwater Standards Manual. This SWMP has evaluated and addressed the potential pollutants associated with this project and their effects on water quality. A summary of the facts and findings associated with this project and the measures addressed by this SWMP is as follows: • The beneficial uses for the receiving waters have been identified. None of these beneficial uses will be impaired or diminish due to the construction and operation of this project. • The Biltmore Pacifica project will not significantly alter drainage patterns on the site. The discharge points will not be changed and all runoff will enter existing public storm drains adequately sized to accommodate the design flow. • Open areas and slopes will be landscaped to reduce or eliminate sediment discharge. • The vegetated swales proposed as part of the project will provide some mitigation of the increased peak flows by detaining flows, reducing the velocities, and providing opportunities for infiltration. • The proposed construction and post-construction BMPs address mitigation measures to protect water quality and protection of water quality objectives and beneficial uses to the maximum extent practicable. This Stormwater Management Plan has been prepared under the direction of the following Registered Civil Engineer. The Registered Civil Engineer attests to the technical information contained herein and the engineering data upon which recommendations, conclusions, and decisions are based. RICHARD G. LANG, RCE 39016 EXP. 03-31-07 DATE No. 39016 Exp. 3-31-05 smx. ATTACHMENT A LOCATION MAP CITY OF OCEANSIDE VISTA PACIFIC OCEAN PROJECT CITY OF SAN MARCOS CITY OF ENCINITAS ATTACHMENT A LOCATION MAP ATTACHMENT B PROJECT MAP ATTACHMENT B PROJECT MAP ATTACHMENT C BMP MAP ATTACHMENT C BMP MAP ATTACHMENT D BMP DATASHEETS Silt Fence SE-1 Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stonnwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Description and Purpose A silt fence is made of a filter fabric that has been entrenched, attached to supporting poles, and sometimes backed by a plastic or wire mesh for support. The silt fence detains sediment-laden water, promoting sedimentation behind the fence. Suitable Applications Silt fences are suitable for perimeter control, placed below areas where sheet flows discharge from the site. They should also be used as interior controls below disturbed areas where runoff may occur in the form of sheet and rill erosion. Silt fences are generally ineffective in locations where the flow is concentrated and are only applicable for sheet or overland flows. Silt fences are most effective when used in combination v«th erosion controls. Suitable applications include: • Along the perimeter of a project. • Below the toe or down slope of exposed and erodible slopes. • Along streams and channels. • Around temporary spoil areas and stockpiles. • Below other small cleared areas. Limitations • Do not use in streams, channels, drain inlets, or anywhere flow is concentrated. Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • Potential Alternatives SE-5 Fiber Rolls SE-6 Gravel Bag Berm SE-8 Sandbag Bamer SE-9 Straw Bale Bamer California Stormwater Ouality Association January 2003 California Stormwater BMP Handbook Construction www.cabmpliandbool<s.com 1 of 8 SE-1 Silt Fence • Do not use in locations where ponded water may cause flooding. • Do not place fence on a slope, or across any contour line. If not installed at the same elevation throughout, silt fences will create erosion. • Filter fences will create a temporary sedimentation pond on the upstream side of the fence and may cause temporary flooding. Fences not constructed on a level contour will be overtopped by concentrated flow resulting in failure of the filter fence. • Improperly installed fences are subject to failure from undercutting, overlapping, or collapsing. - Not effective unless trenched and keyed in. - Not intended for use as mid-slope protection on slopes greater than 4:1 (H:V). Do not allow water depth to exceed 1.5 ft at any point. Implementation General A silt fence is a temporary sediment barrier consisting of filter fabric stretched across and attached to supporting posts, entrenched, and, depending upon the strength of fabric used, supported with plastic or wire mesh fence. Silt fences trap sediment by intercepting and detaining small amounts of sediment-laden runoff from disturbed areas in order to promote sedimentation behind the fence. Silt fences are preferable to straw bale barriers in many cases. Laboratory work at fhe Virginia Highway and Transportation Research Council has shown that silt fences can trap a much higher percentage of suspended sediments than can straw bales. While the failure rate of silt fences is lower than that of straw bale barriers, there are many instances where silt fences have been improperly installed. The following layout and installation guidance can improve performance and should be followed: • Use principally in areas where sheet flow occurs. • Don't use in streams, channels, or anywhere flow is concentrated. Don't use silt fences to divert flow. • Don't use below slopes subject to creep, slumping, or landslides. • Select filter fabric that retains 85% of soil by weight, based on sieve analysis, but that is not finer than an equivalent opening size of 70. • Install along a level contour, so water does not pond more than 1.5 ft at any point along the silt fence. • The maximum length of slope draining to any point along the silt fence should be 200 ft or less. • The maximum slope perpendicular to the fence line should be 1:1. 2 of 8 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Silt Fence SE-1 • Provide sufficient room for runoff to pond behind the fence and to allow sediment removal equipment to pass between the silt fence and toes of slopes or other obstructions. About 1200 ft2 of ponding area should be provided for every acre draining to the fence. • Turn the ends of the filter fence uphill to prevent stormwater from flowing around the fence. • Leave an undisturbed or stabilized area immediately down slope from the fence where feasible. • Silt fences should remain in place until the disturbed area is permanently stabilized. Design and Layout Selection of a filter fabric is based on soil conditions at the construction site (which affect the equivalent opening size (EOS) fabric specification) and characteristics of the support fence (which affect the choice of tensile strength). The designer should specify a filter fabric that retains the soil found on the construction site yet that it has openings large enough to permit drainage and prevent clogging. The following criteria is recommended for selection of the equivalent opening size: 1. If 50 percent or less of the soil, by weight, vnll pass the U.S. Standard Sieve No. 200, select the EOS to retain 85 % of the soil. The EOS should not be finer than EOS 70. 2. For all other soil types, the EOS should be no larger than the openings in the U.S. Standard Sieve No. 70 except where direct discharge to a stream, lake, or wetland v^U occur, then the EOS should be no larger than Standard Sieve No. 100. To reduce fhe chance of clogging, it is preferable to specify a fabric with openings as large as allowed by the criteria. No fabric should be specified with an EOS smaller than U.S. Standard Sieve No. too. If 85% or more of a soil, by weight, passes through the openings in a No. 200 sieve, filter fabric should not be used. Most of the particles in such a soil would not be retained if the EOS was too large and they would clog the fabric quickly if the EOS were small enough to capture the soil. The fence should be supported by a plastic or wire mesh if the fabric selected does not have sufficient strength and bursting strength characteristics for the planned application (as recommended by the fabric manufacturer). Filter fabric material should contain ultraviolet inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of o °F to 120 °F. • Layout in accordance with attached figures. • For slopes steeper than 2:1 (H:V) and that contain a high number of rocks or large dirt clods that tend to dislodge, it maybe necessary to install additional protection immediately adjacent to the bottom of the slope, prior to installing silt fence. Additional protection may be a chain link fence or a cable fence. • For slopes adjacent to sensitive receiving waters or Environmentally Sensitive Areas (ESAs), silt fence should be used in conjunction with erosion control BMPs. January 2003 California Stormwater BMP Handbook 3 of 8 Construction www.cabmphandbooks.com SE-1 Silt Fence Materials • Silt fence fabric should be woven polypropylene with a minimum vddth of 36 in. and a minimum tensile strength of 100 lb force. The fabric should conform to the requirements in ASTM designation D4632 and should have an integral reinforcement layer. The reinforcement layer should be a polypropylene, or equivalent, net provided by the manufacturer. The permittivity of the fabric should be between 0.1 sec ' and 0.15 sec ' in conformance with the requirements in ASTM designation D4491. • Wood stakes should be commercial quality lumber of the size and shape shown on the plans. Each stake should be free from decay, splits or cracks longer than the thickness of the stake or other defects that would weaken the stakes and cause the stakes to be structurally unsuitable. • Staples used to fasten the fence fabric to the stakes should be not less than 1.75 in. long and should be fabricated from 15 gauge or heavier vrire. The vrire used to fasten the tops of the stakes together when joining two sections of fence should be 9 gauge or heavier wire. Galvanizing of the fastening wire will not be required. • There are new products that may use prefabricated plastic holders for the silt fence and use bar reinforcement instead of wood stakes. If bar reinforcement is used in lieu of wood stakes, use number four or greater bar. Provide end protection for any exposed bar reinforcement. InstaZIation Guidelines Silt fences are to be constructed on a level contour. Sufficient area should exist behind the fence for ponding to occur without flooding or overtopping the fence. • A trench should be excavated approximately 6 in. wide and 6 in. deep along the line the proposed silt fence. • Bottom of the silt fence should be keyed-in a minimum of 12 in. • Posts should be spaced a maximum of 6 ft apart and driven securely into the ground a minimum of 18 in. or 12 in. below the bottom of the trench. • When standard strength filter fabric is used, a plastic or v^dre mesh support fence should be fastened securely to the upslope side of posts using heavy-duty wire staples at least 1 in. long. The mesh should extend into the trench. When extra-strength filter fabric and closer post spacing are used, the mesh support fence may be eliminated. Filter fabric should be purchased in a long roll, then cut to the length of the barrier. When joints are necessary, filter cloth should be spliced together only at a support post, with a minimum 6 in. overlap and both ends securely fastened to the post. • The trench should be backfilled with compacted native material. • Construct silt fences vrith a setback of at least 3 ft from the toe of a slope. Where a silt fence is determined to be not practicable due to specific site conditions, the silt fence maybe constructed at the toe of the slope, but should be constructed as far from the toe of the slope as practicable. Silt fences close to the toe of the slope vrill be less effective and difficult to maintain. 4 of 8 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Silt Fence SE-1 • Construct the length of each reach so that the change in base elevation along the reach does not exceed 1/3 the height of the barrier; in no case should the reach exceed 500 ft. Costs • Average annual cost for installation and maintenance (assumes 6 month useful life): $7 per lineal foot ($850 per drainage acre). Range of cost is $3.50 - $9.10 per lineal foot. Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. • Repair undercut silt fences. • Repair or replace split, torn, slumping, or weathered fabric. The lifespan of silt fence fabric is generally 5 to 8 months. • Silt fences that are damaged and become unsuitable for the intended purpose should be removed from the site of work, disposed of, and replaced with new silt fence barriers. • Sediment that accumulates in the BMP must be periodically removed in order to maintain BMP effectiveness. Sediment should be removed when the sediment accumulation reaches one-third of the barrier height. Sediment removed during maintenance may be incorporated into earthwork on the site or disposed at an appropriate location. • Silt fences should be left in place until the upstream area is permanently stabilized. Until then, the silt fence must be inspected and maintained. • Holes, depressions, or other ground disturbance caused by the removal of the silt fences should be backfilled and repaired. References Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Governments, May 1995. National Management Measures to Control Nonpoint Source Pollution from Urban Areas, United States Environmental Protection Agency, 2002. Proposed Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, Work Group-Working Paper, USEPA, April 1992. Sedimentation and Erosion Control Practices, and Inventory of Current Practices (Draft), UESPA, 1990. Southeastern Wisconsin Regional Planning Commission (SWRPC). Costs of Urban Nonpoint Source Water Pollution Control Measures. Technical Report No. 31. Southeastern Wisconsin Regional Planning Commission, Waukesha, WI. 1991 Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. January 2003 California Stormwater BMP Handbook 5 of 8 Construction www.cabmphandbooks.com SE-1 Silt Fence stormwater Management Manual for The Puget Sound Basin, Washington State Department of Ecology, Public Review Draft, 1991. U.S. Environmental Protection Agency (USEPA). Stormwater Management for Industrial Activities: Developing Pollution Prevention Plans and Best Management Practices. U.S. Environmental Protection Agency, Office of Water, Washington, DC, 1992. Water Quality Management Plan for the Lake Tahoe Region, Volume II, Handbook of Management Practices, Tahoe Regional Planning Agency, November 1988. 6 of 8 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com 01 c 01 NJ O O W S s n 5L 3^ -1 0)° 0 (/) 01 rJ cr n o D. -1 §"1 ^ o ^ 2 o O X 01 Q. CT O O VI O Max reoch = 500' (See note 1) Cross barrier (See note 10) NOTES 1. Construct the length of each reach so that the change In base elevation olong the reoch does not exceed 1/3 the height of the linear barrier, in no case sholl the reach length exceed 500'. 2. The last 8'-0" of fence sholl be turned up slope. 3. Stoke dimensions are nominal. 4. Dimension moy vary to fit field condition. 5. Stakes shott be spaced ot 8'-0" maximum and shall be positioned on downstream side of fence. 6. Stokes to overlap and fence fabric to fold around each stoke one full turn. Secure fabric to stoke with 4 staples. 7. Stakes shall be driven tightly together to prevent potential flow-through of sediment at joint. The tops of the stokes shall be secured with wire. 8. For end stoke, fence fabric shall be folded around two stakes one full turn and secured with 4 staples. 9. Minimum 4 staples per stake. Dimensions shown are typical. 10. Cross borriers shall be a minimum of 1/3 ond a maximum of 1/2 the height of the linear barrier. 11. Maintenonce openings shall be constructed in a manner to ensure sediment remains behind silt fence. 12. Joining sections sholl not be ploced at sump locotions. 13. Sondbog rows and layers shall be offset to eliminate gaps. LEGEND Tamped backfill Slope direction Direction of flow •n 3 O End detail -Silt fence -Toe of slope CROSS BARRIER DETAIL Sandbags See note 10 //S5N /-<s^ SECTION C-C m I CO o m n 01 s s n o- n o I?! ift ° I ? 0) Q. CT O O 7r o o 3 c O) O O Ul Setbock varies (See note 4) Slope 2" X 2" Wood stoke (See notes 2 Si. 5) See detail A SECTION A-A Silt fence fobric 6" -2 x 2 wood stake DETAIL A Stake B Fabric section A (See notes 6, 7 <S£ 12) Fabric section B (See notes 6, 7 & 12) Stake A JOINING SECTION DETAIL (TOP VIEW) Fobric (See note 8) ~2' X 2 wood stake (See note 3) 11 END STAKE DETAIL (TOP VIEW) Silt fence ^^SS '•:?5Js~ END DETAIL LEGEND Tamped backfill Slope direction Direction of flow -1 1/16" diameter 1/21 1/2" STAPLE DETAIL (SEE NOTE 9) Toe of slope Sondbags (2-loyers high) OPTIONAL MAINTENANCE OPENING DETAIL (SEE NOTE 11) •n CD 3 o Gravel Bag Berm SE-6 Description and Purpose A gravel bag berm is a series of gravel-filled bags placed on a level contour to intercept sheet flows. Gravel bags pond sheet flow runoff, allowing sediment to settle out, and release runoff slowly as sheet flows, preventing erosion. Suitable Applications Gravel bag berms may be suitable: • As a linear sediment control measure: - Below the toe of slopes and erodible slopes - As sediment traps at culvert/pipe outlets Below other small cleared areas Along the perimeter of a site Down slope of exposed soil areas - Around temporary stockpiles and spoil areas Parallel to a roadway to keep sediment off paved areas - Along streams and channels • As linear erosion control measure: Objectives EC Erosion Control • SE Sediment Control • TC Tracking Control WE Wind Erosion Control NS Non-Stonnwater NS Management Control WM Waste Management and WM Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Targeted Constituents Sediment i Nutrients Trash Metals Bacteria Oil and Grease Organics Potential Alternatives SE-1 Silt Fence SE-5 Fiber Roll SE-8 Sandbag Banier SE-9 Straw Bale Barrier iCaiifornla Stormwater Ouality Assocfatfon January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 4 SE-6 Gravel Bag Berm - Along the face and at grade breaks of exposed and erodible slopes to shorten slope length and spread runoff as sheet flow - At the top of slopes to divert runoff away from disturbed slopes - As check dams across mildly sloped construction roads Limitations • Gravel berms may be difficult to remove. • Removal problems limit their usefulness in landscaped areas. • Gravel bag berm may not be appropriate for drainage areas greater than 5 acres. • Runoff will pond upstream of the filter, possibly causing flooding if sufficient space does not exist. • Degraded gravel bags may rupture when removed, spilling contents. • Installation can be labor intensive. • Berms may have limited durability for long-term projects. • When used to detain concentrated flows, maintenance requirements increase. Implementation General A gravel bag berm consists of a row of open graded gravel-filled bags placed on a level contour. When appropriately placed, a gravel bag berm intercepts and slows sheet flow runoff, causing temporary ponding. The temporary ponding provides quiescent conditions allowing sediment to settle. The open graded gravel in the bags is porous, which allows the ponded runoff to flow slowly through the bags, releasing the runoff as sheet flows. Gravel bag berms also interrupt the slope length and thereby reduce erosion by reducing the tendency of sheet flows to concentrate into rivulets, which erode rills, and ultimately gullies, into disturbed, sloped soils. Gravel bag berms are similar to sand bag barriers, but are more porous. Design and Layout • Locate gravel bag berms on level contours. - Slopes between 20:1 and 2:1 (H:V): Gravel bags should be placed at a maximum interval of 50 ft (a closer spacing is more effective), with the first row near the slope toe. - Slopes 2:1 (H:V) or steeper: Gravel bags should be placed at a maximum interval of 25 ft (a closer spacing is more effective), with the first row placed the slope toe. • Turn the ends of the gravel bag barriers up slope to prevent runoff from going around the berm. • Allow sufficient space up slope from the gravel bag berm to allow ponding, and to provide room for sediment storage. 2 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Gravel Bag Berm SE-6 • For installation near the toe of the slope, consider moving the gravel bag barriers away from the slope toe to facilitate cleaning. To prevent flows behind the barrier, bags can be placed perpendicular to a berm to serve as cross barriers. • Drainage area should not exceed 5 acres. • In Non-Traffic Areas: Height = 18 in. maximum - Top width = 24 in. minimum for three or more layer construction Top width = 12 in. minimum for one or two layer construction Side slopes = 2:1 or flatter • In Construction Traffic Areas: Height = 12 in. maximum Top width = 24 in. minimum for three or more layer construction. Top width = 12 in. minimum for one or two layer construction. Side slopes = 2:1 or flatter. • Butt ends of bags tightly • On multiple row, or multiple layer construction, overlapp butt joints of adjacent row and row beneath. • Use a pyramid approach when stacking bags. Materials • Bag Material: Bags should be woven polypropylene, polyethylene or polyamide fabric or burlap, minimum unit weight of 4 ounces/yd^, Mullen burst strength exceeding 300 Ib/in^ in conformance with the requirements in ASTM designation D3786, and ultraviolet stability exceeding 70% in conformance with the requirements in ASTM designation D4355. • Bag Size: Each gravel-filled bag should have a length of 18 in., width of 12 in., thickness of 3 in., and mass of approximately 33 lbs. Bag dimensions are nominal, and may vary based on locally available materials. • FiZZ Material: Fill material should be 0.5 to 1 in. Class 2 aggregate base, clean and free from clay, organic matter, and other deleterious material, or other suitable open graded, non-cohesive, porous gravel. Costs Gravel filter: Expensive, since off-site materials, hand construction, and demolition/removal are usually required. Material costs for gravel bags are average of $2.50 per empty gravel bag. Gravel costs range firom $20-$35 per yd3. January 2003 California Stormwater BMP Handbook 3 of 4 Construction www.cabmphandbooks.com SE-6 Gravel Bag Berm Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. • Gravel bags exposed to sunlight will need to be replaced every two to three months due to degrading ofthe bags. • Reshape or replace gravel bags as needed. • Repair washouts or other damage as needed. • Sediment that accumulates in the BMP must be periodically removed in order to maintain BMP effectiveness. Sediment should be removed when the sediment accumulation reaches one-third of the barrier height. Sediment removed during maintenance may be incorporated into earthwork on the site or disposed at an appropriate location. • Remove gravel bag berms when no longer needed. Remove sediment accumulation and clean, re-grade, and stabilize the area. Removed sediment should be incorporated in the project or disposed of. References Handbook of Steel Drainage and Highway Construction, American Iron and Steel Institute, 1983. Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Pollution Plan Handbook, First Edition, State of California, Department of Transportation Division of New Technology, Materials and Research, October 1992. 4 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com street Sweeping and Vacuuming SE-7 Objectives Description and Purpose Street sweeping and vacuuming includes use of self-propelled and walk-behind equipment to remove sediment from streets and roadways, and to clean paved surfaces in preparation for final paving. Sweeping and vacuuming prevents sediment from the project site from entering storm drains or receiving waters. Suitable Applications Sweeping and vacuuming are suitable anywhere sediment is tracked from the project site onto public or private paved streets and roads, typically at points of egress. Sweeping and vacuuming are also applicable during preparation of paved surfaces for final paving. Limitations Sweeping and vacuuming may not be effective when sediment is wet or when tracked soil is caked (caked soil may need to be scraped loose). Implementation • Controlling the number of points where vehicles can leave the site will allow sweeping and vacuuming efforts to be focused, and perhaps save money. • Inspect potential sediment tracking locations daily. • Visible sediment tracking should be swept or vacuumed on a daily basis. EC Erosion Control SE Sediment Control • TC Tracking Control • WE Wind Erosion Control NS Non-Stomiwater Management Control WM Waste Management and Materials Pollution Control Legend: ^ Primary Objective • Secondary Objective Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • Potential Alternatives None C S Cl. ^ California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 2 SE-7 Street Sweeping and Vacuuming • Do not use kick brooms or sweeper attachments. These tend to spread the dirt rather than remove it. • If not mixed with debris or trash, consider incorporating the removed sediment back into the project Costs Rental rates for self-propelled sweepers vary depending on hopper size and duration of rental. Expect rental rates from $58/hour (3 yds hopper) to $88/hour (9 yd3 hopper), plus operator costs. Hourly production rates vary with the amount of area to be swept and amount of sediment. Match the hopper size to the area and expect sediment load to minimize time spent dumping. Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. • When actively in use, points of ingress and egress must be inspected daily. • When tracked or spilled sediment is observed outside the construction limits, it must be removed at least daily. More frequent removal, even continuous removal, maybe required in some jurisdictions. • Be careful not to sweep up any unknown substance or any object that may be potentially hazardous. • Adjust brooms frequently; maximize efficiency of sweeping operations. • After sweeping is finished, properly dispose of sweeper wastes at an approved dumpsite. References Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Labor Surcharge and Equipment Rental Rates, State of California Department of Transportation (Caltrans), April 1, 2002 - March 31, 2003. 2 of 2 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Sandbag Barrier SE-8 Description and Purpose A sandbag barrier is a series of sand-filled bags placed on a level contour to intercept sheet flows. Sandbag barriers pond sheet flow runoff, allowing sediment to settle out. Suitable Applications Sandbag barriers may be suitable: • As a linear sediment control measure: Below the toe of slopes and erodible slopes - As sediment traps at culvert/pipe outlets Below other small cleared areas - Along the perimeter of a site Down slope of exposed soil areas - Around temporary stockpiles and spoil areas Parallel to a roadway to keep sediment off paved areas - Along streams and channels • As linear erosion control measure: - Along the face and at grade breaks of exposed and erodible slopes to shorten slope length and spread runoff as sheet flow Objectives EC Erosion Control SE Sediment Control ^ TC Tracking Control WE Wind Erosion Control Non-Stomiwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective J Secondary Objective NS WM Targeted Constituents Sediment ^ Nutrients Trash Metals Bacteria Oil and Grease Organics Potential Alternatives SE-1 Silt Fence SE-5 Fiber Rolls SE-6 Gravel Bag Bemi SE-9 Straw Bale Barrier California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 6 SE-8 Sandbag Barrier - At the top of slopes to divert runoff away from disturbed slopes - As check dams across mildly sloped construction roads Limitations • It is necessary to limit the drainage area upstream of the barrier to 5 acres. • Degraded sandbags may rupture when removed, spilling sand. • Installation can be labor intensive. • Barriers may have limited durability for long-term projects. • When used to detain concentrated flows, maintenance requirements increase. • Burlap should not be used for sandbags. Implementation General A sandbag barrier consists of a row of sand-filled bags placed on a level contour. When appropriately placed, a sandbag barrier intercepts and slows sheet flow runoff, causing temporary ponding. The temporary ponding provides quiescent conditions allowing sediment to settle. While the sand-filled bags are porous, the fine sand tends to quickly plug with sediment, limiting the rate of flow through the barrier. If a porous barrier is desired, consider SE-1, Sih Fence, SE-5, Fiber Rolls, SE-6, Gravel Bag Berms, or SE-9, Straw Bale Barriers. Sandbag barriers also interrupt the slope length and thereby reduce erosion by reducing the tendency of sheet flows to concentrate into rivulets which erode rills, and ultimately gullies, into disturbed, sloped soils. Sandbag barriers are similar to ground bag berms, but less porous. Design and Layout m Locate sandbag barriers on a level contour. Slopes between 20:1 and 2:1 (H:V): Sandbags should be placed at a maximum interval of 50 ft (a closer spacing is more effective), with the first row near the slope toe. - Slopes 2:1 (H:V) or steeper: Sandbags should be placed at a maximum interval of 25 ft (a closer spacing is more effective), with the first row placed near the slope toe. • Turn the ends of the sandbag barrier up slope to prevent runoff from going around the barrier. • Allow sufficient space up slope from the barrier to allow ponding, and to provide room for sediment storage. • For installation near the toe of the slope, consider moving the barrier away from the slope toe to facilitate cleaning. To prevent flow behind the barrier, sandbags can be placed perpendicular to the barrier to serve as cross barriers. • Drainage area should not exceed 5 acres. 2 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Sandbag Barrier SE-8 • Stack sandbags at least three bags high. • Butt ends of bags tightly. • Overlapp butt joints of row beneath with each successive row. • Use a pyramid approach when stacking bags. • In non-traffic areas Height = 18 in. maximum Top width = 24 in. minimum for three or more layer construction Side slope = 2:1 or flatter • In construction traffic areas - Height = 12 in. maximum - Top width = 24 in. minimum for three or more layer construction. Side slopes = 2:1 or flatter. MateriaZs • Sandbag Material: Sandbag should be woven polypropylene, polyethylene or polyamide fabric, minimum unit weight of 4 ounces/yd^, Mullen burst strength exceeding 300 Ib/in^ in conformance with the requirements in ASTM designation D3786, and ultraviolet stability exceeding 70% in conformance with the requirements in ASTM designation D4355. Use of burlap may not acceptable in some jurisdictions. • Sandbag Size: Each sand-filled bag should have a length of 18 in., width of 12 in., thickness of 3 in., and mass of approximately 33 lbs. Bag dimensions are nominal, and may vary based on locally available materials. • Fill Material: All sandbag fill material should be non-cohesive. Class 1 or Class 2 permeable material free from clay and deleterious material. Costs Sandbag barriers are more costly, but typically have a longer useful life than other barriers. Empty sandbags cost $0.25 - $0.75. Average cost of fill material is $8 per yds. Pre-fiUed sandbags are more expensive at $1.50 - $2.00 per bag. Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. • Sandbags exposed to sunlight will need to be replaced every two to three months due to degradation of the bags. • Reshape or replace sandbags as needed. January 2003 California Stormwater BMP Handbook 3 of 6 Construction www,cabmphandbooks.com SE-8 Sandbag Barrier • Repair washouts or other damage as needed. • Sediment that accumulates in the BMP must be periodically removed in order to maintain BMP effectiveness. Sediment should be removed when the sediment accumulation reaches one-third of the barrier height. Sediment removed during maintenance may be incorporated into earthwork on the site or disposed at an appropriate location. • Remove sandbags when no longer needed. Remove sediment accumulation, and clean, re- grade, and stabilize the area. References Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. 4 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com o o n 01 S 2. S 0) 0) rr a- n o I § 3 0) Qi o 3 01 3 Q. cr o o Ul o Max reach = 500' ( See note 1) Sandbag barrier Sandbag barrier (See note 4) 3 a iO 03 fiJ -J 5" SANDBAG BARRIER NOTES 1. Construct the length of each reach so that the change in base elevotion olong the reach does not exceed 1/2 the height of the linear barrier. In no cose shall the reach length exceed 500'. 2. Place sandbags tightly. 3. Dimension may vary to fit field condition. 4. Sandbag barrier shall be a nninimum of 3 bags high. 5. The end of the barrier shall be turned up slope. 6. Cross barriers shall be a min of 1/2 and a max of 2/3 the height of the linear borrier. 7. Sondbog rows and layers shall be staggered to eliminate gaps. m I 00 o n SL I I S. a> 0 01 01 rr cr n o I § 3 01 p fl) o 3 I 01 a. CT o o TT 3 C OJ NJ O O LEGEND DIRECTION OF FLOW Setbock vories (See note 3) Sondbog borrier (See note 4) cn m I 00 SECTION A-A -Slope ( I I I ] , 1 , : 1 1 1 1 1 I -TL; ^V355; '• 7^ 1 SECTION B-B END DETAIL Toe of slope CROSS BARRIER DETAIL SECTION C-C Sondbags See note 6 cn fi) 3 a o- fi) (Q 00 fi) storm Drain Inlet Protection SE-10 Objectives Description and Purpose Storm drain inlet protection consists of a sediment filter or an impounding area around or upstream of a storm drain, drop inlet, or curb inlet. Storm drain inlet protection measures temporarily pond runoff before it enters the storm drain, allowing sediment to settle. Some filter configurations also remove sediment by filtering, but usually the ponding action results in the greatest sediment reduction. Suitable Applications Every storm drain inlet receiving sediment-laden runoff should be protected. Limitations • Drainage area should not exceed i acre. • Straw bales, while potentially effective, have not produced in practice satisfactory results, primarily due to improper installation. • Requires an adequate area for water to pond without encroaching into portions of the roadway subject to traffic. • Inlet protection usually requires other methods of temporary protection to prevent sediment-laden stormwater and non-stormwater discharges from entering the storm drain system. • Sediment removal may be difficult in high flow conditions or if runoff is heavily sediment laden, ff high flow conditions are Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stormwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective •i Secondary Objective EC SE TC WE NS WM Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • Potential Alternatives SE-1 Silt Fence SE-5 Fiber Rolls SE-6 Gravel Bag Benn SE-8 Sandbag Barrier SE-9 Straw Bale Barrier California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 9 SE-10 Storm Drain Inlet Protection expected, use other onsite sediment trapping techniques in conjunction with inlet protection. Frequent maintenance is required. • For drainage areas larger than i acre, runoff should be routed to a sediment-trapping device designed for larger flows. See BMPs SE-2, Sediment Basin, and SE-3, Sediment Traps. • Excavated drop inlet sediment traps are appropriate where relatively heavy flows are expected, and overflow capability is needed. Implementation General Large amounts of sediment may enter the storm drain system when storm drains are installed before the upslope drainage area is stabilized, or where construction is adjacent to an existing storm drain. In cases of extreme sediment loading, the storm drain itself may clog and lose a major portion of its capacity. To avoid these problems, it is necessary to prevent sediment from entering the system at the inlets. Inlet control measures presented in this handbook should not be used for inlets draining more than one acre. Runoff from larger disturbed areas should be first routed through SE-2, Sediment Basin or SE-3, Sediment Trap. Different types of inlet protection are appropriate for different applications depending on site conditions and the type of inlet. Inlet protection methods not presented in this handbook should be approved by the local stormwater management agency. Design and Layout Identify existing and planned storm drain inlets that have the potential to receive sediment- laden surface runoff. Determine if storm drain inlet protection is needed and which method to use. • Limit upstream drainage area to 1 acre maximum. For larger drainage areas, use SE-2, Sediment Basin, or SE-3, Sediment Trap, upstream of the inlet protection device. • The key to successful and safe use of storm drain inlet protection devices is to know where runoff will pond or be diverted. Determine the acceptable location and extent of ponding in the vicinity of the drain inlet. The acceptable location and extent of ponding will influence the type and design of the storm drain inlet protection device. Determine the extent of potential runoff diversion caused by the storm drain inlet protection device. Runoff ponded by inlet protection devices may flow around the device and towards the next downstream inlet. In some cases, this is acceptable; in other cases, serious erosion or downstream property damage can be caused by these diversions. The possibility of runoff diversions will influence whether or not storm drain inlet protection is suitable; and, if suitable, the type and design of the device. • The location and extent of ponding, and the extent of diversion, can usually be controlled through appropriate placement of the inlet protection device. In some cases, moving the 2 of 9 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com storm Drain Inlet Protection SE-10 inlet protection device a short distance upstream of the actual inlet can provide more efficient sediment control, limit ponding to desired areas, and prevent or control diversions. • Four types of inlet protection are presented below. However, it is recognized that other effective methods and proprietary devices exist and may be selected. - Filter Fabric Fence: Appropriate for drainage basins with less than a 5% slope, sheet flows, and flows under 0.5 cfs. Excavated Drop Inlet Sediment Trap: An excavated area around the inlet to trap sediment (SE-3). Gravel bag barrier: Used to create a small sediment trap upstream of inlets on sloped, paved streets. Appropriate for sheet flow or when concentrated flow may exceed 0.5 cfs, and where overtopping is required to prevent flooding. - Block and Gravel Filter: Appropriate for flows greater than 0.5 cfs. • Select the appropriate type of inlet protection and design as referred to or as described in this fact sheet. • Provide area around the inlet for water to pond without flooding structures and property. • Grates and spaces around all inlets should be sealed to prevent seepage of sediment-laden water. • Excavate sediment sumps (where needed) 1 to 2 ft with 2:1 side slopes around the inlet. Installation • DI Protection Type 1 - Filter Fabric Fence - The filter fabric fence (Type 1) protection is shown in the attached figure. Similar to constructing a silt fence; see BMP SE-i, Silt Fence. Do not place filter fabric underneath the inlet grate since the collected sediment may fall into the drain inlet when the fabric is removed or replaced. 1. Excavate a trench approximately 6 in. wide and 6 in. deep along the line of the silt fence inlet protection device. 2. Place 2 in. by 2 in. wooden stakes around the perimeter of the inlet a maximum of 3 ft apart and drive them at least 18 in. into the ground or 12 in. below the bottom of the trench. The stakes must be at least 48 in. 3. Lay fabric along bottom of trench, up side of trench, and then up stakes. See SE-i, Silt Fence, for details. The maximum silt fence height around the inlet is 24 in. 4. Staple the filter fabric (for materials and specifications, see SE-i, Silt Fence) to wooden stakes. Use heavy-duty wire staples at least 1 in. in length. 5. Backfill the trench with gravel or compacted earth all the way around. • DI Protection Type 2 - Excavated Drop Inlet Sediment Trap - The excavated drop inlet sediment trap (Type 2) is shown in the attached figures. Install filter fabric fence in January 2003 California Stormwater BMP Handbook 3 of 9 Construction www.cabmphandbooks.com SE-10 Storm Drain Inlet Protection accordance with DI Protection Type i. Size excavated trap to provide a minimum storage capacity calculated at the rate 67 yd3/acre of drainage area. • DI Protection Type 3 - Gravel bag - The gravel bag barrier (Type 3) is shown in the figures. Flow from a severe storm should not overtop the curb. In areas of high clay and silts, use filter fabric and gravel as additional filter media. Construct gravel bags in accordance with SE-6, Gravel Bag Berm. Gravel bags should be used due to their high permeability. 1. Use sand bag made of geotextile fabric (not burlap) and fill with 0.75 in. rock or 0.25 in. pea gravel. 2. Construct on gently sloping street. 3. Leave room upstream of barrier for water to pond and sediment to settle. 4. Place several layers of sand bags - overlapping the bags and packing them tightly together. 5. Leave gap of one bag on the top row to serve as a spillway. Flow from a severe storm (e.g., 10 year storm) should not overtop the curb. • DI Protection Type 4 — Block and Gravel Filter - The block and gravel filter (Type 4) is shown in the figures. Block and gravel filters are suitable for curb inlets commonly used in residential, commercial, and industrial construction. 1. Place hardware cloth or comparable wire mesh with 0.5 in. openings over the drop inlet so that the wire extends a minimum of 1 ft beyond each side of the inlet structure. If more than one strip is necessary, overlap the strips. Place filter fabric over the wire mesh. 2. Place concrete blocks lengthwise on their sides in a single row around the perimeter of the inlet, so that the open ends face outward, not upward. The ends of adjacent blocks should abut. The height of the barrier can be varied, depending on design needs, by stacking combinations of blocks that are 4 in., 8 in., and 12 in. wide. The row of blocks should be at least 12 in. but no greater than 24 in. high. 3. Place wire mesh over the outside vertical face (open end) ofthe concrete blocks to prevent stone from being washed through the blocks. Use hardware cloth or comparable wire mesh with 0.5 in. opening. 4. Pile washed stone against the wire mesh to the top of the blocks. Use 0.75 to 3 in. Costs • Average annual cost for installation and maintenance (one year useful life) is $200 per inlet. Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non-rainy season. 4 of 9 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com storm Drain Inlet Protection SE-10 • Filter Fabric Fences. If the fabric becomes clogged, torn, or degrades, it should be replaced. Make sure the stakes are securely driven in the ground and are in good shape (i.e., not bent, cracked, or splintered, and are reasonably perpendicular to the ground). Replace damaged stakes. • Gravel Filters. If the gravel becomes clogged with sediment, it must be carefully removed from the inlet and either cleaned or replaced. Since cleaning gravel at a construction site may be difficult, consider using the sediment-laden stone as fill material and put fresh stone around the inlet. Inspect bags for holes, gashes, and snags, and replace bags as needed. Check gravel bags for proper arrangement and displacement. • Sediment that accumulates in the BMP must be periodically removed in order to maintain BMP effectiveness. Sediment should be removed when the sediment accumulation reaches one-third of the barrier height. Sediment removed during maintenance may be incorporated into earthwork on the site ore disposed at an appropriate location. • Remove storm drain inlet protection once the drainage area is stabilized. Clean and regrade area around the inlet and clean the inside of the storm drain inlet as it must be free of sediment and debris at the time of final inspection. References Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management Manual for The Puget Sound Basin, Washington State Department of Ecology, Public Review Draft, 1991. January 2003 California Stormwater BMP Handbook 5 of 9 Construction www.cabmphandbooks.com SE-10 Storm Drain Inlet Protection Geotextile Blanket Silt Fence per SE-01 SECTION A-A 6" Min overlap at ends of silt fence. Geotextile Blanket Silt Fence per SE —01 Dl PROTECTION TYPE 1 NOT TO SCALE NOTES: 1. For use in areas where grading has been completed and final soil stabilization and seeding are pending. 2. Not applicable in paved areas. 3. Not applicable with concentrated flows. 6 of 9 California Stormwater BMP Handbook Construction www.cabmphandbooks.com January 2003 Storm Drain Inlet Protection SE-10 -Stabilize area and grade uniformly around perimeter Note: "^W. Remove sediment before reaching one-third full. Silt fence Per SE-01 12 Min 24" Max Section A —A Concentrated flow Rock filter(use if flow is concentrated) Edge of sediment trap Drain inlet Geotextile Blanket Silt fence Per SE-01 Dl PROTECTION TYPE 2 NOT TO SCALE Notes 1. For use in cleared and grubbed and in graded areas. 2. Shape basin so that longest inflow area faces longest length of trap. 3. For concentrated flows, shape basin in 2:1 ratio with length oriented towards direction of flow. January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 7 of 9 SE-10 Storm Drain Inlet Protection Edge of Pavement Spillway, 1-bag high —' TYPICAL PROTECTION FOR INLET ON SUMP Sandbags 2-bags high Spillway, 1-bag high —' Sandbags 2—bags high TYPICAL PROTECTION FOR INLET ON GRADE NOTES: 1. Intended for short—term use. 2. Use to inhibit non —storm water flow. 3. Allow for proper maintenance and cleanup. 4. Bags must be removed after adjacent operation is completed 5. Not applicable in areas with high silts and clays without filter fabric. Dl PROTECTION TYPE 3 NOT TO SCALE 8 of 9 California Stormwater BMP Handbook Construction www.cabmphandbooks.com January 2003 storm Drain Inlet Protection SE-10 Concrete block laid lengthwise on sides perimeter of opening Hardware cloth or wire mesh Runoff with sediment Curb inlet Dl PROTECTION ^ TYPE 4 NOT TO SCALE January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 9 of 9 Material Delivery and Storage WM-1 Description and Purpose Prevent, reduce, or eliminate the discharge of pollutants from material delivery and storage to the stormwater system or watercourses by minimizing the storage of hazardous materials onsite, storing materials in a designated area, installing secondary containment, conducting regular inspections, and training employees and subcontractors. This best management practice covers only material delivery and storage. For other information on materials, see WM-2, Material Use, or WM-4, Spill Prevention and Control. For information on wastes, see the waste management BMPs in this section. Suitable Applications These procedures are suitable for use at all construction sites vyith delivery and storage of the following materials: • Soil stabilizers and binders • Pesticides and herbicides • Fertilizers • Detergents • Plaster • Petroleum products such as fuel, oil, and grease • Asphalt and concrete components Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stomiwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective y Secondary Objective Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • • • Potential Alternatives None California Stormwater Duality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 5 WM-1 Material Delivery and Storage • Hazardous chemicals such as acids, lime, glues, adhesives, paints, solvents, and curing compounds • Concrete compounds • Other materials that may be detrimental if released to the environment Limitations • Space limitation may preclude indoor storage. • Storage sheds often must meet building and fire code requirements. Implementation The following steps should be taken to minimize risk: • Temporary storage area should be located away from vehicular traffic. • Material Safety Data Sheets (MSDS) should be supplied for all materials stored. • Construction site areas should be designated for material delivery and storage. • Material delivery and storage areas should be located near the construction entrances, away from waterways, if possible. - Avoid transport near drainage paths or waterways. - Surround with earth berms. See EC-9, Earth Dikes and Drainage Swales. Place in an area which will be paved. • Storage of reactive, ignitable, or flammable liquids must comply with the fire codes of your area. Contact the local Fire Marshal to review site materials, quantities, and proposed storage area to determine specific requirements. See the Flammable and Combustible Liquid Code, NFPA30. • An up to date inventory of materials delivered and stored onsite should be kept. • Hazardous materials storage onsite should be minimized. • Hazardous materials should be handled as infrequently as possible. • During the rainy season, consider storing materials in a covered area. Store materials in secondary containments such as earthen dike, horse trough, or even a children's wading pool for non-reactive materials such as detergents, oil, grease, and paints. Small amounts of material may be secondarily contained in "bus boy" trays or concrete mixing trays. • Do not store chemicals, drums, or bagged materials directly on the ground. Place these items on a pallet and, when possible, in secondary containment. 2 of 5 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Material Delivery and Storage WM-1 • If drums must be kept uncovered, store them at a slight angle to reduce ponding of rainwater on the lids to reduce corrosion. Domed plastic covers are inexpensive and snap to the top of drums, preventing water from collecting. • Chemicals should be kept in their original labeled containers. • Employees and subcontractors should be trained on the proper material delivery and storage practices. • Employees trained in emergency spill cleanup procedures must be present when dangerous materials or liquid chemicals are unloaded. • If significant residual materials remain on the ground after construction is complete, properly remove materials and any contaminated soil. See WM-7, Contaminated Soil Management. If the area is to be paved, pave as soon as materials are removed to stabilize the soil. Material Storage Areas and Practices • Liquids, petroleum products, and substances listed in 40 CFR Parts 110,117, or 302 should be stored in approved containers and drums and should not be overfilled. Containers and drums should be placed in temporary containment facilities for storage. • A temporary containment facility should provide for a spill containment volume able to contain precipitation from a 25 year storm event, plus the greater of 10% of the aggregate volume of all containers or 100% of the capacity of the largest container within its boundary, whichever is greater. • A temporary containment facility should be impervious to the materials stored therein for a minimum contact time of 72 hours. • A temporary containment facility should be maintained free of accumulated rainwater and spills. In the event of spills or leaks, accumulated rainwater and spills should be collected and placed into drums. These liquids should be handled as a hazardous waste unless testing determines them to be non-hazardous. All collected liquids or non-hazardous liquids should be sent to an approved disposal site. • Sufficient separation should be provided between stored containers to allow for spill cleanup and emergency response access. • Incompatible materials, such as chlorine and ammonia, should not be stored in the same temporary containment facility. • Throughout the rainy season, each temporary containment facility should be covered during non-working days, prior to, and during rain events. • Materials should be stored in their original containers and the original product labels should be maintained in place in a legible condition. Damaged or otherwise illegible labels should be replaced immediately. January 2003 California Stormwater BMP Handbook 3 of 5 Construction www.cabmphandbooks.com WM-1 Material Delivery and Storage • Bagged and boxed materials should be stored on pallets and should not be allowed to accumulate on the ground. To provide protection from wind and rain throughout fhe rainy season, bagged and boxed materials should be covered during non-working days and prior to and during rain events. • Stockpiles should be protected in accordance with WM-3, Stockpile Management. • Materials should be stored indoors within existing structures or sheds when available. • Proper storage instructions should be posted at all times in an open and conspicuous location. • An ample supply of appropriate spill clean up material should be kept near storage areas. • Also see WM-6, Hazardous Waste Management, for storing of hazardous materials. Material Delivery Practices • Keep an accurate, up-to-date inventory of material delivered and stored onsite. • Arrange for employees trained in emergency spill cleanup procedures to be present when dangerous materials or liquid chemicals are unloaded. Spill Cleanup • Contain and clean up any spill immediately. • Properly remove and dispose of any hazardous materials or contaminated soU if significant residual materials remain on the ground after construction is complete. See WM-7, Contaminated Soil Management. • See WM-4, Spill Prevention and Control, for spills of chemicals and/or hazardous materials. Cost • The largest cost of implementation may be in the construction of a materials storage area that is covered and provides secondary containment. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Keep an ample supply of spill cleanup materials near the storage area. • Keep storage areas clean, well organized, and equipped with ample cleanup supplies as appropriate for the materials being stored. • Repair or replace perimeter controls, containment structures, covers, and liners as needed to maintain proper function. 4 of 5 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Material Delivery and Storage WM-1 References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Coastal Nonpoint Pollution Control Program: Program Development and Approval Guidance, Working Group Working Paper; USEPA, April 1992. Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities; Developing Pollution Prevention Plans and Best Management Practice, EPA 832-R-92005; USEPA, April 1992. January 2003 California Stormwater BMP Handbook 5 of 5 Construction www.cabmphandbooks.com stockpile Management WM-3 Description and Purpose Stockpile Management procedures and practices are designed to reduce or eliminate air and stormwater pollution from stockpiles of soil, paving materials such as portland cement concrete (PCC) rubble, asphalt concrete (AC), asphalt concrete rubble, aggregate base, aggregate sub base or pre-mixed aggregate, asphalt minder (so called "cold mix" asphalt), and pressure treated wood. Suitable Applications Implement in all projects that stockpile soil and other materials. Limitations None identified. Implementation Protection of stockpiles is a year-round requirement. To properly manage stockpiles: • Locate stockpiles a minimum of 50 ft away from concentrated flows of stormwater, drainage courses, and inlets. • Protect all stockpiles from stormwater runon using a temporary perimeter sediment barrier such as berms, dikes, fiber rolls, silt fences, sandbag, gravel bags, or straw bale barriers. Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stormwater Management Control Waste Management and Materials Pollution Control Legend: •/ Primary Objective / Secondary Objective Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • • • • Potential Alternatives None J^^. California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www. cabmphandbooks. com 1 of 3 WM-3 Stockpile Management • Implement wind erosion control practices as appropriate on all stockpiled material. For specific information, see WE-i, Wind Erosion Control. • Manage stockpiles of contaminated soil in accordance with WM-7, Contaminated Soil Management. • Place bagged materials on pallets and under cover. Protection o/Non-Active Stockpiles Non-active stockpiles of the identified materials should be protected further as follows: SOJ7 stockpiles • During the rainy season, soil stockpiles should be covered or protected with soil stabilization measures and a temporary perimeter sediment barrier at all times. • During the non-rainy season, soil stockpiles should be covered or protected with a temporary perimeter sediment barrier prior to the onset of precipitation. Stockpiles of Portland cement concrete rubble, aspfialt concrete, asphalt concrete rubble, aggregate base, or aggregate sub base • During the rainy season, the stockpiles should be covered or protected with a temporary perimeter sediment barrier at all times. • During the non-rainy season, the stockpiles should be covered or protected with a temporary perimeter sediment barrier prior to the onset of precipitation. Stockpiles of "cold mix" • During the rainy season, cold mix stockpiles should be placed on and covered with plastic or comparable material at all times. • During the non-rainy season, cold mix stockpiles should be placed on and covered with plastic or comparable material prior to the onset of precipitation. Stockpiles/Storage of pressure treated wood with copper, chromium, and arsenic or ammonical, copper, zinc, and arsenate • During the rainy season, treated wood should be covered with plastic or comparable material at all times. • During the non-rainy season, treated wood should be covered with plastic or comparable material at all times and cold mix stockpiles should be placed on and covered with plastic or comparable material prior to the onset of precipitation. Protection qf Active Stockpiles Active stockpiles of the identified materials should be protected further as follows: • All stockpiles should be protected with a temporary linear sediment barrier prior to the onset of precipitation. • Stockpiles of "cold mix" should be placed on and covered with plastic or comparable material prior to the onset of precipitation. 2 of 3 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com stockpile Management WM-3 Costs All of the above are low cost measures. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation • Repair and/or replace perimeter controls and covers as needed to keep them functioning properly. References Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. January 2003 California Stormwater BMP Handbook 3 of 3 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 Description and Purpose Prevent or reduce the discharge of pollutants to drainage systems or watercourses from leaks and spills by reducing the chance for spills, stopping the source of spills, containing and cleaning up spills, properly disposing of spill materials, and training employees. This best management practice covers only spill prevention and control. However, WM-i, Materials Delivery and Storage, and WM-2, Material Use, also contain useful information, particularly on spill prevention. For information on wastes, see the waste management BMPs in this section. Suitable Applications This BMP is suitable for all construction projects. Spill control procedures are implemented anytime chemicals or hazardous substances are stored on the construction site, including the following materials: • Soil stabilizers/binders • Dust palliatives • Herbicides • Growth inhibitors • Fertilizers • Deicing/anti-icing chemicals Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stormwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • • • Potential Alternatives None California Stormwater Ouality ^Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 6 Spill Prevention and Control WM-4 • Fuels • Lubricants • Other petroleum distillates Limitations • In some cases it may be necessary to use a private spill cleanup company. • This BMP applies to spills caused by the contractor and subcontractors. • Procedures and practices presented in this BMP are general. Contractor should identify appropriate practices for the specific materials used or stored onsite Implementation The following steps will help reduce the stormwater impacts of leaks and spills: £ducatton • Be aware that different materials pollute in different amounts. Make sure that each employee knows what a "significant spill" is for each material they use, and what is the appropriate response for "significant" and "insignificant" spills. • Educate employees and subcontractors on potential dangers to humans and the environment from spills and leaks. • Hold regular meetings to discuss and reinforce appropriate disposal procedures (incorporate into regular safety meetings). • Establish a continuing education program to indoctrinate new employees. • Have contractor's superintendent or representative oversee and enforce proper spill prevention and control measures. General Measures m To the extent that the work can be accomplished safely, spills of oil, petroleum products, substances listed under 40 CFR parts 110,117, and 302, and sanitary and septic wastes should be contained and cleaned up immediately. • Store hazardous materials and wastes in covered containers and protect from vandalism. • Place a stockpile of spill cleanup materials where it will be readily accessible. • Train employees in spill prevention and cleanup. • Designate responsible individuals to oversee and enforce control measures. • Spills should be covered and protected from stormwater runon during rainfall to the extent that it doesn't compromise clean up activities. • Do not bury or wash spills with water. 2 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 • Store and dispose of used clean up materials, contaminated materials, and recovered spill material that is no longer suitable for the intended purpose in conformance with the provisions in applicable BMPs. • Do not allow water used for cleaning and decontamination to enter storm drains or watercourses. Collect and dispose of contaminated water in accordance with WM-io, Liquid Waste Management. • Contain water overflow or minor water spillage and do not allow it to discharge into drainage facilities or watercourses. • Place proper storage, cleanup, and spill reporting instructions for hazardous materials stored or used on the project site in an open, conspicuous, and accessible location. • Keep waste storage areas clean, well organized, and equipped with ample cleanup supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers, and liners should be repaired or replaced as needed to maintain proper function. Cleanup • Clean up leaks and spills immediately. • Use a rag for small spills on paved surfaces, a damp mop for general cleanup, and absorbent material for larger spills. If the spilled material is hazardous, then the used cleanup materials are also hazardous and must be sent to either a certified laundry (rags) or disposed of as hazardous waste. • Never hose down or bury dry material spills. Clean up as much of the material as possible and dispose of properly. See the waste management BMPs in this section for specific information. Minor Spills • Minor spills typically involve small quantities of oil, gasoline, paint, etc. which can be controlled by the first responder at the discovery of the spill. • Use absorbent materials on small spills rather than hosing down or burying the spill. • Absorbent materials should be promptly removed and disposed of properly. • Follow the practice below for a minor spill: Contain the spread of the spill. Recover spilled materials. Clean the contaminated area and properly dispose of contaminated materials. Semi-Significant Spills • Semi-significant spills still can be controlled by the first responder along with the aid of other personnel such as laborers and the foreman, etc. This response may require the cessation of all other activities. January 2003 California Stormwater BMP Handbook 3 of 6 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 • Spills should be cleaned up immediately: - Contain spread of the spill. - Notify the project foreman immediately. - If the spill occurs on paved or impermeable surfaces, clean up using "dry" methods (absorbent materials, cat litter and/or rags). Contain the spill by encircling with absorbent materials and do not let the spill spread widely. - If the spill occurs in dirt areas, immediately contain the spill by constructing an earthen dike. Dig up and properly dispose of contaminated soil. If the spill occurs during rain, cover spill with tarps or other material to prevent contaminating runoff. Significant/Hazardous Spills m For significant or hazardous spills that cannot be controlled by personnel in the immediate vicinity, the following steps should be taken: - Notify the local emergency response by dialing 911. In addition to 911, the contractor will notify the proper county officials. It is the contractor's responsibilify to have all emergency phone numbers at the construction site. - Notify the Governor's Office of Emergency Services Warning Center, (916) 845-8911. For spills of federal reportable quantities, in conformance with the requirements in 40 CFR parts 110,119, and 302, the contractor should notify the National Response Center at (800) 424-8802. - Notification should first be made by telephone and followed up with a written report. - The services of a spills contractor or a Haz-Mat team should be obtained immediately. Construction personnel should not attempt to clean up until the appropriate and qualified staffs have arrived at the job site. Other agencies which may need to be consulted include, but are not limited to, the Fire Department, the Public Works Department, the Coast Guard, the Highway Patrol, the City/County Police Department, Department of Toxic Substances, California Division of Oil and Gas, Cal/OSHA, etc. Reporting • Report significant spills to local agencies, such as the Fire Department; they can assist in cleanup. • Federal regulations require that any significant oil spill into a water body or onto an adjoining shoreline be reported to the National Response Center (NRC) at 800-424-8802 (24 hours). Use the following measures related to specific activities: 4 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 Vehicle and Equipment Maintenance • If maintenance must occur onsite, use a designated area and a secondary containment, located away from drainage courses, to prevent the runon of stormwater and the runoff of spills. • Regularly inspect onsite vehicles and equipment for leaks and repair immediately • Check incoming vehicles and equipment (including delivery trucks, and employee and subcontractor vehicles) for leaking oil and fluids. Do not allow leaking vehicles or equipment onsite. • Always use secondary containment, such as a drain pan or drop cloth, to catch spills or leaks when removing or changing fluids. • Place drip pans or absorbent materials under paving equipment when not in use. • Use absorbent materials on small spills rather than hosing down or burying the spill. Remove the absorbent materials promptly and dispose of properly. • Promptly transfer used fluids to the proper waste or recycling drums. Don't leave full drip pans or other open containers lying around • Oil filters disposed of in trashcans or dumpsters can leak oil and pollute stormwater. Place the oil filter in a funnel over a waste oil-recycling drum to drain excess oil before disposal. Oil filters can also be recycled. Ask the oil supplier or recycler about recycling oil filters. • Store cracked batteries in a non-leaking secondary container. Do this with all cracked batteries even if you think all the acid has drained out. If you drop a battery, treat it as if it is cracked. Put it into the containment area until you are sure it is not leaking. Vehlcie and Equipment Fueling • If fueling must occur onsite, use designate areas, located away from drainage courses, to prevent the runon of stormwater and the runoff of spills. • Discourage "topping off' of fuel tanks. • Always use secondary containment, such as a drain pan, when fiieling to catch spills/ leaks. Costs Prevention of leaks and spills is inexpensive. Treatment and/ or disposal of contaminated soil or water can be quite expensive. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect BMPs subject to non-stormwater discharge daily while non-stormwater discharges occur. January 2003 California Stormwater BMP Handbook 5 of 6 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 • Keep ample supplies of spill control and cleanup materials onsite, near storage, unloading, and maintenance areas. • Update your spill prevention and control plan and stock cleanup materials as changes occur in the types of chemicals onsite. References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Stormwater Qualify Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities; Developing Pollution Prevention Plans and Best Management Practice, EPA 832-R-92005; USEPA, April 1992. 6 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Solid Waste Management WM-5 Description and Purpose Solid waste management procedures and practices are designed to prevent or reduce the discharge of pollutants to stormwater from solid or construction waste by providing designated waste collection areas and containers, arranging for regular disposal, and training employees and subcontractors. Suitable Applications This BMP is suitable for construction sites where the following wastes are generated or stored: • Solid waste generated from trees and shrubs removed during land clearing, demolition of existing structures (rubble), and building construction • Packaging materials including wood, paper, and plastic • Scrap or surplus building materials including scrap metals, rubber, plastic, glass pieces and masonry products • Domestic wastes including food containers such as beverage cans, coffee cups, paper bags, plastic wrappers, and cigarettes • Construction wastes including brick, mortar, timber, steel and metal scraps, pipe and electrical cuttings, non- hazardous equipment parts, styrofoam and other materials used to transport and package construction materials Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stonnwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Targeted Constituents Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • • • • Potential Alternatives None California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 4 WM-5 Solid Waste Management • Highway planting wastes, including vegetative material, plant containers, and packaging materials Limitations Temporary stockpiling of certain construction wastes may not necessitate stringent drainage related controls during the non-rainy season or in desert areas with low rainfall. Implementation The following steps wUl help keep a clean site and reduce stormwater pollution: • Select designated waste collection areas onsite. • Inform trash-hauling contractors that you will accept only watertight dumpsters for onsite use. Inspect dumpsters for leaks and repair any dumpster that is not watertight. • Locate containers in a covered area or in a secondary containment. • Provide an adequate number of containers with lids or covers that can be placed over the container to keep rain out or to prevent loss of wastes when it is windy. • Plan for additional containers and more firequent pickup during the demolition phase of construction. • Collect site trash daily, especially during rainy and windy conditions. • Remove this solid waste promptly since erosion and sediment control devices tend to collect litter. • Make sure that toxic liquid wastes (used oils, solvents, and paints) and chemicals (acids, pesticides, additives, curing compounds) are not disposed of in dumpsters designated for construction debris. • Do not hose out dumpsters on the construction site. Leave dumpster cleaning to the trash hauling contractor. • Arrange for regular waste collection before containers overflow. • Clean up immediately if a container does spill. • Make sure that construction waste is collected, removed, and disposed of only at authorized disposal areas. Education • Have the contractor's superintendent or representative oversee and enforce proper solid waste management procedures and practices. • Instruct employees and subcontractors on identification of solid waste and hazardous waste. • Educate employees and subcontractors on solid waste storage and disposal procedures. 2 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Solid Waste Management WM-5 • Hold regular meetings to discuss and reinforce disposal procedures (incorporate into regular safefy meetings). • Require that employees and subcontractors follow solid waste handling and storage procedures. • Prohibit littering by employees, subcontractors, and visitors. • Minimize production of solid waste materials wherever possible. Collection, Storage, and Disposal • Littering on the project site should be prohibited. • To prevent clogging of the storm drainage system, litter and debris removal from drainage grates, trash racks, and ditch lines should be a priorify. • Trash receptacles should be provided in the contractor's yard, field trailer areas, and at locations where workers congregate for lunch and break periods. • Litter from work areas within the construction limits of the project site should be collected and placed in watertight dumpsters at least weekly, regardless of whether the litter was generated by the contractor, the public, or others. Collected litter and debris should not be placed in or next to drain inlets, stormwater drainage systems, or watercourses. • Dumpsters of sufficient size and number should be provided to contain the solid waste generated by the project. • Full dumpsters should be removed from the project site and the contents should be disposed of by the trash hauling contractor. • Construction debris and waste should be removed from the site biweekly or more frequently as needed. • Construction material visible to the public should be stored or stacked in an orderly manner. • Stormwater runon should be prevented from contacting stored solid waste through the use of berms, dikes, or other temporary diversion structures or through the use of measures to elevate waste from site surfaces. • Solid waste storage areas should be located at least 50 ft from drainage facilities and watercourses and should not be located in areas prone to flooding or ponding. • Except during fair weather, construction and highway planting waste not stored in watertight dumpsters should be securely covered from wind and rain by covering the waste with tarps or plastic. • Segregate potentially hazardous waste from non-hazardous construction site waste. • Make sure that toxic liquid wastes (used oils, solvents, and paints) and chemicals (acids, pesticides, additives, curing compounds) are not disposed of in dumpsters designated for construction debris. January 2003 California Stormwater BMP Handbook 3 of 4 Construction www.cabmphandbooks.com WM-5 Solid Waste Management • For disposal of hazardous waste, see WM-6, Hazardous Waste Management. Have hazardous waste hauled to an appropriate disposal and/or recycling facilify. • Salvage or recycle useful vegetation debris, packaging and surplus building materials when practical. For example, trees and shrubs from land clearing can be used as a brush barrier, or converted into wood chips, then used as mulch on graded areas. Wood pallets, cardboard boxes, and construction scraps can also be recycled. Costs All of the above are low cost measures. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect BMPs subject to non-stormwater discharge daily while non-stormwater discharges occur • Inspect construction waste area regularly. • Arrange for regular waste collection. References Processes, Procedures and Methods to Control Pollution Resulting from All Construction Activity, 430/9-73-007, USEPA, 1973. Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities; Developing Pollution Prevention Plans and Best Management Practice, EPA 832-R-92005; USEPA, April 1992. 4 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Concrete Waste Management WM-8 Objectives EC SE TC WE NS WM Description and Purpose Prevent or reduce the discharge of pollutants to stormwater from concrete waste by conducting washout offsite, performing onsite washout in a designated area, and training employee and subcontractors. Suitable Applications Concrete waste management procedures and practices are implemented on construction projects where: • Concrete is used as a construction material or where concrete dust and debris result form demolition activities • Slurries containing portland cement concrete (PCC) or asphalt concrete (AC) are generated, such as from saw cutting, coring, grinding, grooving, and hydro-concrete demolition • Concrete trucks and other concrete-coated equipment are washed onsite • Mortar-mixing stations exist • See also NS-8, Vehicle and Equipment Cleaning Limitations • Offsite washout of concrete wastes may not always be possible. Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stonnwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Targeted Constituents Sediment i Nutrients Trash Metals 1 Bacteria Oil and Grease Organics Potential Alternatives None California Stormwater Ouality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 7 WM-8 Concrete Waste Management Implementation The following steps will help reduce stormwater pollution from concrete wastes: • Discuss the concrete management techniques described in this BMP (such as handling of concrete waste and washout) with the ready-mix concrete supplier before any deliveries are made. • Incorporate requirements for concrete waste management into material supplier and subcontractor agreements. • Store dry and wet materials under cover, away from drainage areas. • Avoid mixing excess amounts of fresh concrete. • Perform washout of concrete trucks offsite or in designated areas only. • Do not wash out concrete trucks into storm drains, open ditches, streets, or streams. • Do not allow excess concrete to be dumped onsite, except in designated areas. • For onsite washout: Locate washout area at least 50 feet from storm drains, open ditches, or water bodies. Do not allow runoff from this area by constructing a temporary pit or bermed area large enough for liquid and solid waste. - Wash out wastes into the temporary pit where the concrete can set, be broken up, and then disposed properly. • Avoid creating runoff by draining water to a bermed or level area when washing concrete to remove fine particles and expose the aggregate. • Do not wash sweepings from exposed aggregate concrete into the street or storm drain. Collect and return sweepings to aggregate base stockpile or dispose in the trash. Edwcation • Educate employees, subcontractors, and suppliers on the concrete waste management techniques described herein. • Arrange for contractor's superintendent or representative to oversee and enforce concrete waste management procedures. Concrete Slurry Wastes • PCC and AC waste should not be allowed to enter storm drains or watercourses. • PCC and AC waste should be collected and disposed of or placed in a temporary concrete washout facility. • A sign should be installed adjacent to each temporary concrete washout facility to inform concrete equipment operators to utilize the proper facilities. 2 of 7 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Concrete Waste Management WM-8 • Below grade concrete washout facilities are typical. Above grade facilities are used if excavation is not practical. • A foreman or construction supervisor should monitor onsite concrete working tasks, such as saw cutting, coring, grinding and grooving to ensure proper methods are implemented. • Saw-cut PCC slurry should not be allowed to enter storm drains or watercourses. Residue from grinding operations should be picked up by means of a vacuum attachment to the grinding machine. Saw cutting residue should not be allowed to flow across the pavement and should not be left on the surface of the pavement. See also NS-3, Paving and Grinding Operations; and WM-10, Liquid Waste Management. • Slurry residue should be vacuumed and disposed in a temporary pit (as described in OnSite Temporary Concrete Washout Facility, Concrete Transit Truck Washout Procedures, below) and allowed to dry. Dispose of dry slurry residue in accordance with WM-5, Solid Waste Management. Onsite Temporary Concrete Washout Facility, Transit Truck Washout Procedures • Temporary concrete washout facilities should be located a minimum of 50 ft from storm drain inlets, open drainage facilities, and watercourses. Each facility should be located away from construction traffic or access areas to prevent disturbance or tracking. • A sign should be installed adjacent to each washout facility to inform concrete equipment operators to utilize the proper facilities. • Temporary concrete washout facilities should be constructed above grade or below grade at the option of the contractor. Temporary concrete washout facilities should be constructed and maintained in sufficient quantity and size to contain all liquid and concrete waste generated by washout operations. • Temporary washout facilities should have a temporary pit or bermed areas of sufficient volume to completely contain all liquid and waste concrete materials generated during washout procedures. • Washout of concrete trucks should be performed in designated areas only. • Only concrete from mixer truck chutes should be washed into concrete wash out. • Concrete washout from concrete pumper bins can be washed into concrete pumper trucks and discharged into designated washout area or properly disposed of offsite. • Once concrete wastes are washed into the designated area and allowed to harden, the concrete should be broken up, removed, and disposed of per WM-5, Solid Waste Management. Dispose of hardened concrete on a regular basis. • Temporary Concrete Washout Facility (Type Above Grade) Temporary concrete washout facility (type above grade) should be constructed as shown on the details at the end of this BMP, with a recommended minimum length and January 2003 California Stormwater BMP Handbook 3 of 7 Construction www.cabmphandbooks.com WM-8 Concrete Waste Management minimum width of lo ft, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. Straw bales, wood stakes, and sandbag materials should conform to the provisions in SE- 9, Straw Bale Barrier. - Plastic lining material should be a minimum of lo mil in polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. • Temporary Concrete Washout Facility (Type Below Grade) - Temporary concrete washout facilities (type below grade) should be constructed as shown on the details at the end of this BMP, with a recommended minimum length and minimum width of lo ft. The quantity and volume should be sufficient to contain all liquid and concrete waste generated by washout operations. Lath and flagging should be commercial type. - Plastic lining material should be a minimum of lo mil polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. Removal of Temporary Concrete Washout Facilities m When temporary concrete washout facilities are no longer required for the work, the hardened concrete should be removed and disposed of. Materials used to construct temporary concrete washout facilities should be removed from the site of the work and disposed of. • Holes, depressions or other ground disturbance caused by the removal of the temporary concrete washout facilities should be backfilled and repaired. Costs All of the above are low cost measures. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Temporary concrete washout facilities should be maintained to provide adequate holding capacity with a minimum freeboard of 4 in. for above grade facilities and 12 in. for below grade facilities. Maintaining temporary concrete washout facilities should include removing and disposing of hardened concrete and returning the facilities to a functional condition. Hardened concrete materials should be removed and disposed of. • Washout facilities must be cleaned, or new facilities must be constructed and ready for use once the washout is 75% full. 4 of 7 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Concrete Waste Management WM-8 References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities; Developing Pollution Prevention Plans and Best Management Practice, EPA 832-R-92005; USEPA, April 1992. January 2003 California Stormwater BMP Handbook 5 of 7 Construction www.cabmphandbooks.com WM-8 Concrete Waste Management LATH & FLAGGING ON ALL SIDES BERM 10 MIL PLASTIC LINING PLAN NOT TO SCALE TYPE "BELOW GRADE" SANDBAG SANDBAG- 10 MIL PLASTIC LINING BERM SECTION A-A NOT TO SCALE •—s- TWO-STACKED 2 X 12 ROUGH WOOD FRAME 10' MIN -STAKE (TYP) 10 MIL PLASTIC LINING 10 MIL PLASTIC LINING PLAN NOT TO SCALE TYPE "ABOVE GRADE" WOOD FRAME SECURELY FASTENED AROUND ENTIRE PERIMETER WITH TWO STAKES SECTION B-B NOT TO SCALE NOTES 1. ACTUAL LAYOUT DETERMINED IN FIELD. 2. THE CONCRETE WASHOUT SIGN SHALL BE INSTALLED WITHIN 30 FT. OF THE TEMPORARY CONCRETE WASHOUT FACILITY. 6 of 7 California Stormwater BMP Handbook Construction www.cabmphandbooks.com January 2003 Concrete Waste Management WM-8 10 MIL- PLASTIC LINING PLAN MIN \ - - NOT TO SCALE TYPE "ABOVE GRADE" WITH STRAW BALES -STAKE (TYP) B i STI 1/8" EEL DIA. WIRE -STRAW BALE (TYP) CONCRETE WASHOU' STAPLE DETAIL PLYWOOD 48" X 24" -PAINTED WHITE -BLACK LETTERS 6" HEIGHT 0,5" LAG SCREWS -WOOD POST 3" X 3" X 8' CONCRETE WASHOUT SIGN DETAIL (OR EQUIVALENT) STAPLES (2 PER BALE) NATIVE MATERIAL- (OPTIONAL) -10 MIL PLASTIC LINING WOOD OR- METAL STAKES (2 PER BALE) SECTION B-B NOT TO SCALE BINDING WIRE STRAW BALE NOTES 1. ACTUAL LAYOUT DETERMINED IN FIELD. 2. THE CONCRETE WASHOUT SIGN SHALL BE INSTALLED WITHIN 30 FT, OF THE TEMPORARY CONCRETE WASHOUT FACILITY. January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 7 of 7 stabilized Construction Entrance/Exit TC-1 Objectives EC Erosion Control SE Sediment Control • TC Tracking Control • WE Wind Erosion Control NS Non-Stonnwater NS Management Control WM Waste Management and WM Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Description and Purpose A stabilized construction access is defined by a point of entrance/exit to a construction site that is stabilized to reduce the tracking of mud and dirt onto public roads by construction vehicles. Suitable Applications Use at construction sites: • Where dirt or mud can be tracked onto public roads. • Adjacent to water bodies. • Where poor soils are encountered. • Where dust is a problem during dry weather conditions. Limitations • Entrances and exits require periodic top dressing with additional stones. • This BMP should be used in conjunction with street sweeping on adjacent public right of way. • Entrances and exits should be constructed on level ground only. • Stabilized construction entrances are rather expensive to construct and when a wash rack is included, a sediment trap of some kind must also be provided to collect wash water runoff. Targeted Constituents Sediment t Nutrients Trash Metals Bacteria Oil and Grease Organics Potential Alternatives None California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 6 stabilized Construction Entrance/Exit TC-1 Implementation GcneraZ A stabilized construction entrance is a pad of aggregate underlain with filter cloth located at any point where traffic will be entering or leaving a construction site to or from a public right of way, street, alley, sidewalk, or parking area. The purpose of a stabilized construction entrance is to reduce or eliminate the tracking of sediment onto public rights of way or streets. Reducing tracking of sediments and other pollutants onto paved roads helps prevent deposition of sediments into local storm drains and production of airborne dust. Where traffic will be entering or leaving the construction site, a stabilized construction entrance should be used. NPDES permits require that appropriate measures be implemented to prevent tracking of sediments onto paved roadways, where a significant source of sediments is derived from mud and dirt carried out from unpaved roads and construction sites. Stabilized construction entrances are moderately effective in removing sediment from equipment leaving a construction site. The entrance should be built on level ground. Advantages of the Stabilized Construction Entrance/Exit is that it does remove some sediment from equipment and serves to channel construction traffic in and out of the site at specified locations. Efficiency is greatly increased when a washing rack is included as part of a stabilized construction entrance/exit. Design and Layout m Construct on level ground where possible. • Select 3 to 6 in. diameter stones. • Use minimum depth of stones of 12 in. or as recommended by soils engineer. • Construct length of 50 ft minimum, and 30 ft minimum width. • Rumble racks constructed of steel panels with ridges and installed in the stabilized entrance/exit will help remove additional sediment and to keep adjacent streets clean. • Provide ample turning radii as part of the entrance. • Limit the points of entrance/exit to the construction site. • Limit speed of vehicles to control dust. • Properly grade each construction entrance/exit to prevent runoff from leaving the construction site. • Route runoff from stabilized entrances/exits through a sediment trapping device before discharge. • Design stabilized entrance/exit to support heaviest vehicles and equipment that will use it. • Select construction access stabilization (aggregate, asphaltic concrete, concrete) based on longevity, required performance, and site conditions. Do not use asphalt concrete (AC) grindings for stabilized construction access/roadway. 2 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com stabilized Construction Entrance/Exit TC-1 • If aggregate is selected, place crushed aggregate over geotextile fabric to at least 12 in. depth, or place aggregate to a depth recommended by a geotechnical engineer. A crushed aggregate greater than 3 in. but smaller than 6 in. should be used. • Designate combination or single purpose entrances and exits to the construction site. • Require that all employees, subcontractors, and suppliers utilize the stabilized construction access. • Implement SE-7, Street Sweeping and Vacuuming, as needed. • All exit locations intended to be used for more than a two-week period should have stabilized construction entrance/exit BMPs. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMPs are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect local roads adjacent to the site daily. Sweep or vacuum to remove visible accumulated sediment. • Remove aggregate, separate and dispose of sediment if construction entrance/exit is clogged v^th sediment. • Keep all temporary roadway ditches clear. • Check for damage and repair as needed. • Replace gravel material when surface voids are visible. • Remove all sediment deposited on paved roadways within 24 hours. • Remove gravel and filter fabric at completion of construction Costs Average annual cost for installation and maintenance may vary from $1,200 to $4,800 each, averaging $2,400 per entrance. Costs will increase with addition of washing rack, and sediment trap. With wash rack, costs range from $1,200 - $6,000 each, averaging $3,600 per entrance. References Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Governments, May 1995. National Management Measures to Control Nonpoint Source Pollution from Urban Areas, USEPA Agency, 2002. Proposed Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, Work Group Working Paper, USEPA, April 1992. January 2003 California Stormwater BMP Handbook 3 of 6 Construction www.cabmphandbooks.com stabilized Construction Entrance/Exit TC-1 Stormwater Quality Handbooks Construction Site Best Management Practices (BMPs) Manual, State of CaHfornia Department of Transportation (Caltrans), November 2000. Stormwater Management of the Puget Sound Basin, Technical Manual, Publication #91-75, Washington State Department of Ecology, February 1992. Virginia Erosion and Sedimentation Control Handbook, Virginia Department of Conservation and Recreation, Division of Soil and Water Conservation, 1991. Guidance Specifying Management Measures for Nonpoint Pollution in Coastal Waters, EPA 840-B-9-002, USEPA, Office of Water, Washington, DC, 1993. Water Quality Management Plan for the Lake Tahoe Region, Volume II, Handbook of Management Practices, Tahoe Regional Planning Agency, November 1988. 4 of 6 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com stabilized Construction Entrance/Exit TC-1 Crushed aggregate greater than 3" but smaller than 6" I •Filter fabric Original 1-12 " Min, unless otherwise specified by a soils engineer SECTION B-B NTS >-< Q < o Q: Q Ld > < CL cn X UJ NOTE: Construct sediment barrier " and channelize runoff to sediment trapping device Match Existing Grade or four times the circumference of the largest construction vehicle tire, whichever is greater PLAN NTS Width as reguired to accomodate anticipated traffic January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 5 of 6 stabilized Construction Entrance/Exit TC-1 Crushed aggregate greater than 3" but smaller than 6". Filter fabrii Original L 1 9" 12 Min, unless otherwise specified by a soils engineer SECTION B-B NTS Crushed aggregate greater than 3" but smaller than 6". Corrugated steel panels Original r ||uxrijTjT_run_njTjTjTjTj-Cn^^ i— Uligill 12" Min, unless otherwise specified by a soils engineer •Filter fabric SECTION A-A NOT TO SCALE NOTE: Construct sediment barrier and channelize runoff to sediment trapping device Sediment trapping device Corrugated steel panels A 10' min or as required to accomodate anticipoted traffic, whichever is greater. Match Existing Grade or four times the circumference of the largest construction vehicle tire, whichever is greater PLAN NTS 6 of 6 California Stormwater BMP Handbook Construction www.cabmphandbooks.com January 2003 Dewatering Operations NS-2 Objectives EC Erosion Control SE Sediment Control TC Tracking Control WE Wind Erosion Control NS Non-Stonnwater • NS Management Control • WM Waste Management and WM Materials Pollution Control Legend: ^ Primary Objective •f Secondary Objective Description and Purpose Dewatering operations are practices that manage the discharge of pollutants when non-stormwater and accumulated precipitation must be removed from a work location so that construction work may be accomplished. Suitable Applications These practices are implemented for discharges of non- stormwater from construction sites. Non-stormwaters include, but are not limited to, groundwater, water from cofferdams, water diversions, and waters used during construction activities that must be removed from a work area. Practices identified in this section are also appropriate for implementation when managing the removal of accumulated precipitation (stormwater) from depressed areas at a construction site. Limitations • Site conditions will dictate design and use of dewatering operations. • The controls discussed in this best management practice (BMP) address sediment only. • The controls detailed in this BMP only allow for minimal settling time for sediment particles. Use only when site conditions restrict the use of the other control methods. • Dewatering operations will require, and must comply with, applicable local permits. Targeted Constituents Sediment < Nutrients Trash Metals Bacteria Oil and Grease i Organics Potential Alternatives SE-5: Fiber Roll SE-6: Gravel Bag Berm SE-9: Straw Bale Barrier California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 11 NS-2 Dewatering Operations • Avoid dewatering discharges where possible by using the water for dust control, by infiltration, etc. Implementation • Dewatering non-stormwater cannot be discharged without prior notice to and approval from the Regional Water Quality Control Board (RWQCB) and local stormwater management agency. This includes stormwater that is co-mingled with groundwater or other non- stormwater sources. Once the discharge is allowed, appropriate BMPs must be implemented to ensure the discharge complies with all permit requirements and regional and watershed- specific requirements. • RWQCB may require a separate NPDES permit prior to the dewatering discharge of non- stormwater. These permits will have specific testing, monitoring, and discharge requirements and can take significant time to obtain. • The flow chart shown in Figure i should be utilized to guide dewatering operations. • The owner will coordinate monitoring and permit compliance. • Additional permits or permissions from other agencies may be required for dewatering cofferdams or diversions. • Dewatering discharges must not cause erosion at the discharge point. A variety of methods can be used to treat water during dewatering operations. Several devices are presented below and provide options to achieve sediment removal. The size of particles present in the sediment and Permit or receiving water limitations on sediment are key considerations for selecting sediment treatment option(s); in some cases, the use of multiple devices may be appropriate. Sediment Basin (see also SE-2) Description: m A sediment basin is a temporary basin with a controlled release structure that is formed by excavation or construction of an embankment to detain sediment-laden runoff and allow sediment to settle out before discharging. Sediment basins are generally larger than Sediment Traps (SE-3). Appropriate Applications: u Effective for the removal of gravel, sand, silt, some metals that settle out with the sediment, and trash. Implementation: • Excavation and construction of related facilities is required. • Temporary sediment basins must be fenced if safety is a concern. • Outlet protection is required to prevent erosion at the outfall location. 2 of 11 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Dewatering Operations NS-2 Maintenance: • Maintenance is required for safety fencing, vegetation, embankment, inlet and outfall structures, as well as other features. • Removal of sediment is required when the storage volume is reduced by one-half. Sediment Trap (See also SE-3) Description: • A sediment trap is a temporary basin formed by excavation and/or construction of an earthen embankment across a waterway or low drainage area to detain sediment-laden runoff and allow sediment to settle out before discharging. Sediment traps are generally smaller than Sediment Basins (SE-2). Appropriate Applications: Effective for the removal of large and medium sized particles (sand and gravel) and some metals that settle out with the sediment. Implementation: • Excavation and construction of related facilities is required. • Trap inlets should be located to maximize the travel distance to the trap outlet. • Use rock or vegetation to protect the trap outlets against erosion. Maintenance: • Maintenance is required for vegetation, embankment, inlet and outfall structures, as well as other features. • Removal of sediment is required when the storage volume is reduced by one-third. January 2003 California Stormwater BMP Handbook 3 of 11 Construction www.cabmphandbooks.com NS-2 Dewatering Operations Weir Tanks Descripfion; • A weir tank separates water and waste by using weirs. The configuration of the weirs (over and under weirs) maximizes the residence time in the tank and determines the waste to be removed from the water, such as oil, grease, and sediments. Appropriate Applications: • The tank removes trash, some settleable solids (gravel, sand, and silt), some visible oil and grease, and some metals (removed with sediment). To achieve high levels of flow, multiple tanks can be used in parallel. If additional treatment is desired, the tanks can be placed in series or as pre-treatment for other methods. Implementation: m Tanks are delivered to the site by the vendor, who can provide assistance with set-up and operation. • Tank size will depend on flow volume, constituents of concern, and residency period required. Vendors should be consulted to appropriately size tank. Maintenance: • Periodic cleaning is required based on visual inspection or reduced flow. • Oil and grease disposal must be by licensed waste disposal company. 4 of 11 California Stormwater BMP Handbook Construction www .cabmphandbooks.com January 2003 Dewatering Operations NS-2 Dewatering Tanks Description: • A dewatering tank removes debris and sediment. Flow enters the tank through the top, passes through a fabric filter, and is discharged through the bottom of the tank. The filter separates the solids from the liquids. Appropriate Applications: • The tank removes trash, gravel, sand, and silt, some visible oil and grease, and some metals (removed with sediment). To achieve high levels of flow, multiple tanks can be used in parallel. If additional treatment is desired, the tanks can be placed in series or as pre- treatment for other methods. /mpZementafion; • Tanks are delivered to the site by the vendor, who can provide assistance with set-up and operation. • Tank size will depend on flow volume, constituents of concern, and residency period required. Vendors should be consulted to appropriately size tank. Maintenance: • Periodic cleaning is required based on visual inspection or reduced flow. • Oil and grease disposal must be by licensed waste disposal company. January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 5 of 11 NS-2 Dewatering Operations Gravity Bag Filter AVAIWBLE IN VARIOUS \ } ) SHAPES ANO SIZES FOR ^^fttix* — SEDIMENT CONTAINMENT |,f -4*5' TIEDOwP^ H STRAP \^ r. 1 If I SyT" fATER PUMP I I > DEWATERING BAG WATER PUMP PUMP DISCHARGE HOSE FILTERED WATER Description: • A gravity bag filter, also referred to as a dewatering bag, is a square or rectangular bag made of non-woven geotextile fabric that collects sand, silt, and fines. Appropriate Applications: • Effective for the removal of sediments (gravel, sand, and silt). Some metals are removed with the sediment. Implementation; • Water is pumped into one side of the bag and seeps through the bottom and sides of the bag. • A secondary barrier, such as a rock filter bed or straw/hay bale barrier, is placed beneath and beyond the edges of the bag to capture sediments that escape the bag. Maintenance; • Inspection of the flow conditions, bag condition, bag capacity, and the secondary barrier is required. • Replace the bag when it no longer filters sediment or passes water at a reasonable rate. • The bag is disposed of offsite. 6 of 11 California Stormwater BMP Handbook Construction www.cabmphandbooks.com January 2003 Dewatering Operations NS-2 Sand Media Particulate Filter Description: • Water is treated by passing it through canisters filled with sand media. Generally, sand filters provide a final level of treatment. They are often used as a secondary or higher level of treatment after a significant amount of sediment and other pollutants have been removed using other methods. Appropriate Applications: m Effective for the removal of trash, gravel, sand, and silt and some metals, as well as the reduction of biochemical oxygen demand (BOD) and turbidity. • Sand filters can be used for stand-alone treatment or in conjunction with bag and cartridge filtration if further treatment is required. • Sand filters can also be used to provide additional treatment to water treated via settling or basic filtration. JmpZementation; • The filters require delivery to the site and initial set up. The vendor can provide assistance with installation and operation. Maintenance; • The filters require regular service to monitor and maintain the level of the sand media. If subjected to high loading rates, filters can plug quickly. • Venders generally provide data on maximum head loss through the filter. The filter should be monitored daily while in use, and cleaned when head loss reaches target levels. • If cleaned by backwashing, the backwash water may need to be hauled away for disposal, or returned to the upper end of the treatment train for another pass through the series of dewatering BMPs. January 2003 California Stormwater BMP Handbook 7 of 11 Construction www.cabmphandbooks.com NS-2 Dewatering Operations Pressurized Bag Filter Description: • A pressurized bag filter is a unit composed of single filter bags made from polyester felt material. The water filters through the unit and is discharged through a header. Vendors provide bag filters in a variety of configurations. Some units include a combination of bag filters and cartridge filters for enhanced contaminant removal. Appropriate Applications: u Effective for the removal of sediment (sand and silt) and some metals, as well as the reduction of BOD, turbidity, and hydrocarbons. Oil absorbent bags are available for hydrocarbon removal. • Filters can be used to provide secondary treatment to water treated via settling or basic filtration. /mpZementation; • The filters require delivery to the site and initial set up. The vendor can provide assistance with installation and operation. Maintenance; • The filter bags require replacement when the pressure differential equals or exceeds the manufacturer's recommendation. 8 of 11 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Dewatering Operations NS-2 Cartridge Filter Description: • Cartridge filters provide a high degree of pollutant removal by utilizing a number of individual cartridges as part of a larger filtering unit. They are often used as a secondary or higher (polishing) level of treatment after a significant amount of sediment and other pollutants are removed. Units come with various cartridge configurations (for use in series with bag filters) or with a larger single cartridge filtration unit (with multiple filters within). Appropriate Applications: • Effective for the removal of sediment (sand, silt, and some clays) and metals, as well as the reduction of BOD, turbidity, and hydrocarbons. Hydrocarbons can effectively be removed with special resin cartridges. • Filters can be used to provide secondary treatment to water treated via settling or basic filtration. Implementation: • The filters require delivery to the site and initial set up. The vendor can provide assistance. Maintenance; • The cartridges require replacement when the pressure differential equals or exceeds the manufacturer's recommendation. Costs • Sediment controls are low to high cost measures depending on the dewatering system that is selected. Pressurized filters tend to be more expensive than gravity settling, but are often more effective. Simple tanks are generally rented on a long-term basis (one or more months) and can range from $360 per month for a 1,000 gallon tank to $2,660 per month for a 10,000 gallon tank. Mobilization and demobilization costs vary considerably. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and at two-week intervals in the non-rainy season to verify continued BMP implementation. January 2003 California Stormwater BMP Handbook 9 of 11 Construction www.cabmphandbooks.com NS-2 Dewatering Operations • Inspect BMPs subject to non-stormwater discharges daily while non-stormwater discharges occur. • Unit-specific maintenance requirements are included with the description of each unit. • Sediment removed during the maintenance of a dewatering device may be either spread onsite and stabilized, or disposed of at a disposal site as approved by the owner. • Sediment that is commingled with other pollutants must be disposed of in accordance with all applicable laws and regulations and as approved by the owner. • References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities, Developing Pollution Prevention Plans and Best Management Practices, EPA 832-R-92005; USEPA, April 1992. Labor Surcharge & Equipment Rental Rates, April 1, 2002 through March 31, 2003, California Department of Transportation (Caltrans). 10 of 11 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Dewatering Operations NS-2 Assess water quality and eliminaie discharge flow rate and volume No, it is in Region lor 2, or is groundwater or cofferdam/ diversion dewatering Dewatering Operations Management Flow Chart Dewatering of groundwater, cofferdams, or diversions, and discharge of accumulated precipitation is addressed in this flow chart. Contact a Stormwater quality professional for guidance on all other discharges. Notes: MGD Million Gallons per Day NPDES National Pollutant Discharge Elimination System RWQCB Regional Water Quality Control Board Implement sediment control BMPs Discharge water to storm drain or water tiody Monitor and maintain to ensure sediment controls are working and to prevent erosion at outfall Maintain monitoring records with SWPPP and provide to RWQCB if required Figure 1 Operations Flow Chart January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 11 of 11 Vehicle & Equipment l^aintenance NS-10 Objectives Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stonnwater Management Control Waste Management and Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective EC SE TC WE NS WM Targeted Constituents Description and Purpose Prevent or reduce the contamination of stormwater resulting from vehicle and equipment maintenance by running a "dry and clean site". The best option would be to perform maintenance activities at an offsite facility. If this option is not available then work should be performed in designated areas only, while providing cover for materials stored outside, checking for leaks and spills, and containing and cleaning up spills immediately. Employees and subcontractors must be trained in proper procedures. Suitable Applications These procedures are suitable on all construction projects where an onsite yard area is necessary for storage and maintenance of heavy equipment and vehicles. Limitations Onsite vehicle and equipment maintenance should only be used where it is impractical to send vehicles and equipment offsite for maintenance and repair. Sending vehicles/equipment offsite should be done in conjunction with TC-i, Stabilized Construction Entrance/Exit. Outdoor vehicle or equipment maintenance is a potentially significant source of stormwater pollution. Activities that can contaminate stormwater include engine repair and service, changing or replacement of fluids, and outdoor equipment storage and parking (engine fluid leaks). For further information on vehicle or equipment servicing, see NS-8, Vehicle and Equipment Cleaning, and NS-9, Vehicle and Equipment Fueling. Sediment Nutrients Trash Metals Bacteria Oil and Grease Organics • • • • Potential Alternatives None California Stormwater OuaKty Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 4 NS-10 Vehicle St Equipment Maintenance Implementation • Use offsite repair shops as much as possible. These businesses are better equipped to handle vehicle fluids and spills properly. Performing this work offsite can also be economical by eliminating the need for a separate maintenance area. • If maintenance must occur onsite, use designated areas, located away from drainage courses. Dedicated maintenance areas should be protected from stormwater runon and runoff, and should be located at least 50 ft from downstream drainage facilities and watercourses. • Drip pans or absorbent pads should be used during vehicle and equipment maintenance work that involves fluids, unless the maintenance work is performed over an impermeable surface in a dedicated maintenance area. • Place a stockpile of spill cleanup materials where it will be readily accessible. • All fueling trucks and fueling areas are required to have spill kits and/or use other spill protection devices. • Use adsorbent materials on small spUls. Remove the absorbent materials promptly and dispose of properly. • Inspect onsite vehicles and equipment daily at startup for leaks, and repair immediately. • Keep vehicles and equipment clean; do not allow excessive build-up of oil and grease. • Segregate and recycle wastes, such as greases, used oil or oil filters, antifreeze, cleaning solutions, automotive batteries, hydraulic and transmission fluids. Provide secondary containment and covers for these materials if stored onsite. • Train employees and subcontractors in proper maintenance and spill cleanup procedures. • Drip pans or plastic sheeting should be placed under all vehicles and equipment placed on docks, barges, or other structures over water bodies when the vehicle or equipment is planned to be idle for more than 1 hour. • For long-term projects, consider using portable tents or covers over maintenance areas if maintenance cannot be performed offsite. • Consider use of new, alternative greases and lubricants, such as adhesive greases, for chassis lubrication and fifth-wheel lubrication. • Properly dispose of used oils, fluids, lubricants, and spill cleanup materials. • Do not place used oil in a dumpster or pour into a storm drain or watercourse. • Properly dispose of or recycle used batteries. • Do not bury used tires. • Repair leaks of fluids and oil immediately. 2 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Vehicle & Equipment Maintenance NS-10 Listed below is further information if you must perform vehicle or equipment maintenance onsite. Safer Aitemative Products • Consider products that are less toxic or hazardous than regular products. These products are often sold under an "environmentally friendly" label. • Consider use of grease substitutes for lubrication of truck fifth-wheels. Follow manufacturers label for details on specific uses. • Consider use of plastic friction plates on truck fifth-wheels in lieu of grease. Follow manufacturers label for details on specific uses. Waste Reduction Parts are often cleaned using solvents such as trichloroethylene, trichloroethane, or methylene chloride. Many of these cleaners are listed in California Toxic Rule as priority pollutants. These materials are harmful and must not contaminate stormwater. They must be disposed of as a hazardous waste. Reducing the number of solvents makes recycling easier and reduces hazardous waste management costs. Often, one solvent can perform a job as well as two different solvents. Also, if possible, eliminate or reduce the amount of hazardous materials and waste by substituting non-hazardous or less hazardous materials. For example, replace chlorinated organic solvents with non-chlorinated solvents. Non-chlorinated solvents like kerosene or mineral spirits are less toxic and less expensive to dispose of properly. Check the list of active ingredients to see whether it contains chlorinated solvents. The "chlor" term indicates that the solvent is chlorinated. Also, try substituting a wire brush for solvents to clean parts. Recycling and Disposal Separating wastes allows for easier recycling and may reduce disposal costs. Keep hazardous wastes separate, do not mix used oil solvents, and keep chlorinated solvents (like,- trichloroethane) separate from non-chlorinated solvents Oike kerosene and mineral spirits). Promptly transfer used fluids to the proper waste or recycling drums. Don't leave full drip pans or other open containers lying around. Provide cover and secondary containment until these materials can be removed from the site. Oil filters can be recycled. Ask your oil supplier or recycler about recycling oil filters. Do not dispose of extra paints and coatings by dumping liquid onto the ground or throwing it into dumpsters. Allow coatings to dry or harden before disposal into covered dumpsters. Store cracked batteries in a non-leaking secondary container. Do this with all cracked batteries, even if you think all the acid has drained out. If you drop a battery, treat it as if it is cracked. Put it into the containment area until you are sure it is not leaking. Costs All of the above are low cost measures. Higher costs are incurred to setup and maintain onsite maintenance areas. January 2003 California Stormwater BMP Handbook 3 of 4 Construction www.cabmphandbooks.com NS-10 Vehicle & Equipment Maintenance Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and at two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect BMPs subject to non-stormwater discharges daily while non-stormwater discharges occur. • Keep ample supplies of spill cleanup materials onsite. • Maintain waste fluid containers in leak proof condition. • Vehicles and equipment should be inspected on each day of use. Leaks should be repaired immediately or the problem vehicle(s) or equipment should be removed from the project site. • Inspect equipment for damaged hoses and leaky gaskets routinely. Repair or replace as needed. References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Coastal Nonpoint Pollution Control Program; Program Development and Approval Guidance, Working Group, Working Paper; USEPA, April 1992. Stormwater Quality Handbooks - Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. 4 of 4 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Entrance/Outlet Tire Wash TC-3 Description and Purpose A tire wash is an area located at stabilized construction access points to remove sediment from tires and under carriages and to prevent sediment from being transported onto public roadways. Suitable Applications Tire washes may be used on construction sites where dirt and mud tracking onto public roads by construction vehicles may occur. Limitations • The tire wash requires a supply of wash water. • A turnout or doublewide exit is required to avoid having entering vehicles drive through the wash area. • Do not use where wet tire trucks leaving the site leave the road dangerously slick. Implementation • Incorporate with a stabilized construction entrance/exit. See TC-1, Stabilized Construction Entrance/Exit. • Construct on level ground when possible, on a pad of coarse aggregate greater than 3 in. but smaller than 6 in. A geotextile fabric should be placed below the aggregate. • Wash rack should be designed and constructed/manufactured for anticipated traffic loads. Objectives EC Erosion Control SE Sediment Control TC Tracking Control • WE Wind Erosion Control NS Non-Stomfiwater NS Management Control WM Waste Management and WM Materials Pollution Control Legend: ^ Primary Objective / Secondary Objective Targeted Constituents Sediment ^ Nutrients Trash Metals Bacteria Oil and Grease Organics Potential Alternatives TC-1 Stabilized Construction Entrance/Exit California Stormwater Ouality Association January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 1 of 3 TC-3 Entrance/Outlet Tire Wash • Provide a drainage ditch that will convey the runoff from the wash area to a sediment trapping device. The drainage ditch should be of sufficient grade, width, and depth to carry the wash runoff. • Use hoses with automatic shutoff nozzles to prevent hoses from being left on. • Require that all employees, subcontractors, and others that leave the site with mud caked tires and undercarriages to use the wash facility. • Implement SC-y, Street Sweeping and Vacuuming, as needed. Costs Costs are low for installation of wash rack. Inspection and Maintenance • Inspect and verify that activify-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect BMPs subject to non-stormwater discharge daily while non-stormwater discharges occur. • Remove accumulated sediment in wash rack and/or sediment trap to maintain system performance. • Inspect routinely for damage and repair as needed. References Blueprint for a Clean Bay: Best Management Practices to Prevent Stormwater Pollution from Construction Related Activities; Santa Clara Valley Nonpoint Source Pollution Control Program, 1995- Coastal Nonpoint Pollution Control Program; Program Development and Approval Guidance, Working Group, Working Paper; USEPA, April 1992. Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Governments, May 1995. Stormwater Quality Handbooks Construction Site Best Management Practices (BMPs) Manual, State of California Department of Transportation (Caltrans), November 2000. Stormwater Management for Construction Activities, Developing Pollution Prevention Plans and Best Management Practices, EPA 832-R-92005; USEPA, April 1992. 2 of 3 California Stormwater BMP Handbook January 2003 Construction www.cabmphandbooks.com Entrance/Outlet Tire Wash TC-3 Crushed aggregate greater than 3' but smaller than 6". Corrugated steel panels Original ^^^^^^^^^^^^^ grade 12" Min, unless otherwise specified by a soils engineer Filter fabric SECTION A-A NOT TO SCALE Crushed aggregate greater than 3' but smaller than 6" •Filter fabric Original grade 12 Min, unless otherwise specified by a soils engineer SECTION B-B NTS Ditch to carry runoff to 0 sediment trapping device NOTE: Many designs can be field fabricated, or fabricated units may be used. Water supply & hose TYPICAL TIRE WASH NOT TO SCALE January 2003 California Stormwater BMP Handbook Construction www.cabmphandbooks.com 3 of 3