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Participant HandbookNorth Central Texas Council of Governments Inspection of Storm Water Pollution Prevention Practices during Construction Participant Handbook Fifth Edition Table of Contents Preface Part 1: Introduction, Regulations, and Inspections of Construction Activities Part 2: Storm Water Best Management Practices for Construction Activities Appendices: Inspection Forms Quizzes Glossary Reference List Preface Land disturbance during construction activities is a large contributor to the environmental problem of erosion and sedimentation. Understanding the various methods (best management practices) used to prevent erosion and sedimentation (E &S) will help developers /contractors and inspectors implement effective E &S controls. The North Central Texas Council of Governments and its regional consultant have developed a comprehensive training curriculum to help address the problem of erosion and sedimentation at construction sites. Though each municipality and agency will approach the problem somewhat differently, this course provides instruction that is appropriate to almost all programs. The purpose of the training program is to instruct participants in the following areas: • The importance of erosion and sediment controls. • The environmental problems associated with lack of erosion and sediment controls. • The causes of erosion and sedimentation. • The inspection and maintenance of erosion and sediment controls. Understanding the importance of controlling erosion and sedimentation at construction sites will help inspectors and developers to comply with regulations, avoid costly problems, and protect the environment. Part 1: Introduction, Regulations, and Inspections of Construction Activities Erosion and Sedimentation, a Three -Part Process • Erosion is the wearing away of the soil by forces such as water and wind. • Surface flow or wind carries loose soil particles away. • Sedimentation occurs when the velocity of wind or water slows to allow eroded material to settle out. Important Pointy] rel North Central Texas Council of Governments Inspection of Storm Water Pollution Prevention Practices during Construction Important Points • This course provides instruction appropriate to almost all programs; however, each municipality /agency will approach some things differently. I Goal • To train municipal personnel inspecting storm water pollution prevention requirements at construction sites using consistent inspection guidelines Important Points • Recognize that storm water pollution control from construction sites is the responsibility of multiple parties -- developer, engineer, contractor, and inspector. ♦ The inspector's responsibility includes not only enforcement of the rules and requirements, but also the facilitation of compliance. • Resources to be used in class: ♦ Handbook Glossary is provided in appendix ♦ Sample Plans ♦ Video 2 Course Outline • Erosion and sedimentation theory • Brief overview of regulatory requirements for construction sites • Guidelines for municipal personnel inspecting storm water pollution prevention practices on construction sites • Common erosion and sediment control measures • Proper installation and maintenance of BMPs Important Points 1, � &kC"1 Why is Construction Identified as a Problem? • Construction is a specialized type of industrial activity • Intense, varied activities occur in a limited area • Erosion and sedimentation are the largest potential problem from these sites • Potential exists for other pollutants (such as debris and on -site chemicals) to reach waterways Important Points 4 Erosion and Sedimentation Theory • To implement effective E &S controls and enforce E &S requirements, we need to understand: ♦ The process of erosion and sedimentation ♦ Factors affecting the rate of erosion ♦ Effects and costs of erosion and sedimentation ♦ Ways to reduce and control storm water pollution from erosion and sedimentation Important Points Factors Affecting Rate of Erosion • Rate of erosion due to water depends on: ♦ Type and amount of energy (rainfall and flow) ♦ Length and steepness of slope ♦ Erodibility of soil ♦ Management of land Important Points • The extent of erosion depends on: ♦ Amount and velocity of water. ♦ Type of soil: The erosive forces of water (raindrops or flowing water) or wind break the natural bonds between soil particles. ♦ Type and amount of soil cover. Impacts of Erosion and Sedimentation • Suspended solids from erosion are the largest source of pollutants in waterways. • Effects: ♦ Reduction in fish populations ♦ Transportation of pollutants ♦ Increase in hazard and severity of flooding • Costly problems are caused by sedimentation: ♦ Increased maintenance cost to remove sediment Important Points] • Erosion is the largest source of pollutants in waterways. • Effects: ♦ Reduction of fish populations: Sediments increase turbidity, reduce light penetration, cover fish spawning area, clog and harm gills and interfere with their feeding habits. ♦ Transportation of pollutants: Chemicals such as trace metals, pesticides, phosphorus, and ammonia are adsorbed and transported by sediment. ♦ Increase in hazard and severity of flooding: Sediments clog rivers, decrease reservoir capacity, reduce recreation and scenic value, as well as increase the hazard and severity of flooding. • Costs to correct problems caused by sedimentation: ♦ Maintenance costs to remove sediment from road ditches, dredge sediments from rivers, lakes and reservoirs and remove chemicals from the water supply. ♦ Environmental cost of degraded habitats. 8 The Water Quality Act of 1987 • The Clean Water Act was amended in 1987 to require the implementation of a comprehensive national program for addressing :storm water pollution • Regulations cover storm water discharges from certain construction activities and from Municipal Separate Storm Sewer Systems (MS4s) • Regulations have been implemented in two phases • The Texas Commission on Environmental Quality created the Texas Pollutant Discharge Elimination System (TPDES) program to regulate storm water discharges Important Points] 0 Storm Water Regulations • Phase I ♦ Large Construction Activities • Sites > 5 acres; Administered by TCEQ ♦ Large & Medium MS4 Management Program for Construction • No size specified; Administered by the MS4 • Phase II ♦ Small Construction Activities • Sites > 1 acre and < 5 acres; Administered by TCEQ ♦ Small MS4 Construction Site Runoff Control • Sites > 1 acre; Administered by the MS4 Important Points] (AC) � not A MA 10 Large Construction Activity • All construction activity disturbing > 5 acres • Regulated since early 90's • Large construction activities were previously regulated by EPA under the NPDES Construction General Permit • TCEQ issued the TPDES Construction General Permit TXR150000 effective March 5, 2003 Important Points] Small Construction Activity • Construction activity disturbing > 1 acre and < 5 acres • Previously unregulated at the federal or state level in Texas • Permit coverage currently required under TPDES Construction General Permit TXR150000 Important Points] 1 12 21 MS4 Permit Issues • Phase I cities ♦ Enforce, local ordinances ♦ Refer violators of TPDES Construction General Permit to TCEQ in accordance with local procedures • Phase II cities and counties ♦ Develop a plan under the Construction Site Runoff Control Minimum Measure ♦ Implement plan over 5 year permit term IAW schedule and enforce local ordinances ♦ Refer violators of TPDES Construction General Permit to TCEQ in accordance with local procedures Important Points] psi TPDES General Permit for Construction Activities • Before construction, operators are required to: ♦ Develop Storm Water Pollution Prevention Plan (SWPPP); and ♦ Submit Notice of Intent (for large construction activities) or post Construction Site Notice (for small construction activities) prior to start of construction • The "operator" is either: ♦ the person or persons that have operational control over construction plans and specifications; or ♦ the person or persons that have day -to -day operational control of those activities at a construction site Note: This workbook provides summarized information from the Construction General Permit and is not intended for use in regulatory compliance. Rlefer to TPDES General Permit No. TXR150000 for complete permit requirements. Important Points] • Developer /contractor is responsible for NOI, SWPPP and NOT -- not the City! • Many cities may require developer /contractor to submit Erosion & Sedimentation Control Plan and the Storm Water Pollution Prevention Plan for their review • This workbook provides summarized information from the Construction General Permit and is not intended for use in regulatory compliance. Refer to TPDES General Permit No. TXR150000 for complete permit requirements. 14 TPDES General Permit for Construction Activities • During construction, operators must: ♦ Install and maintain BMPs to prevent and control pollution ♦ Temporarily or permanently stabilize areas where construction activities have been suspended or completed • Before terminating coverage, operators must: ♦ Perform final site inspection to ensure that final stabilization of site is achieved ♦ Remove all temporary measures and ensure that site is completed per plan Important Point;] oU -c - TPDES General Permit Storm Water Pollution Prevention Plan • Elements of SWPPP: ♦ Site /project information ♦ Best Mlanagement Practices • Erosion and sediment controls, stabilization practices, and structural control practices • Permanent storm water controls ♦ Other controls to minimize pollutants • Dust, vehicle tracking, waste materials, concrete or asphalt batch plants, velocity dissipation ♦ Regular maintenance and inspection of BMPs Important Points] VV - 4`14, 16 ite/Project Information • Site description, project and soil conditions • Anticipated construction schedule and phasing of BMPs • Detailed Site Map • Copy of the Construction General Permit Important Points] • Site Plan should show: ♦ drainage patterns and approximate slopes anticipated after major grading activities; ♦ areas where soil disturbance will occur; ♦ locations of all major structural controls either planned or in place; ♦ locations where stabilization practices are expected to be used; ♦ locations of off -site material, waste, borrow, fill, or equipment storage areas; ♦ surface waters (including wetlands) either adjacent or in close proximity; ♦ locations where storm water discharges from the site directly to a surface water body; ♦ the location of asphalt plants and concrete plants providing support to the construction site; ♦ the name of receiving waters at or near the site that will be disturbed or that will receive discharges from disturbed areas of the project. SWPPP Best Management Practices • Erosion and sediment controls, stabilization practices, and structural control practices ♦ Must be designed to retain sediment to the extent practicable ♦ Includes retention of existing vegetation, temporary or permanent vegetative cover, mulching erosion control matting, diversion dikes, sediment traps and basins, check dams, silt fence, etc. • Permanent storm water controls ♦ Measures installed during construction that will control pollutants in discharges after construction operations have been completed ♦ Could include wet ponds, constructed wetlands, buffer strips, etc Important Points] 18 SWPPP Other Controls • Minimize off -site vehicle tracking and dust generation • Controls to reduce pollutants from construction and waste materials ♦ Construction materials storage and disposal areas ♦ Equipment storage /maintenance /cleaning areas • Controls to reduce pollutants from concrete and asphalt plants • Velocity dissipation devices to provide non - erosive flows in storm water discharges Important Points' I 19 SWPPP Maintenance & Inspection • Maintenance ♦ Erosion and sediment control measures and other protective measures must be maintained in effective operating condition ♦ Maintenance on poorly performing BMPs must be conducted prior to the next storm event or as soon as practicable ♦ Maintenance of BMPs that have been intentionally disabled or removed must be replaced or corrected immediately upon discovery • Personnel provided by the operator must inspect: ♦ Disturbed areas that have not been finally stabilized ♦ Materials storage areas ♦ Erosion and sediment control measures and structural controls ♦ Vehicle entrances and exits Important Points] 20 Maintenance & Inspection (Cont.) • Operator inspection frequency ♦ At minimum once every 14 calendar days and within 24 hours after a storm of 0.5 -inch or greater; or ♦ Once every 7 calendar days regardless of rainfall • Operator inspection reports contents ♦ Name and qualifications of inspector(s), date of inspection ♦ Locations of sediment or pollutant discharges ♦ Locations of BMPs that need maintenance, have failed to operate as designed or are inadequate, and/or where additional BMPs are needed • SWPPP Modification ♦ SWPPP must be modified by the operator within 7 days of inspection if deficiencies are identified Important Points] jm" c w� 21 Operator's Responsibilities • Develop SWPPP and obtain TPDES permit coverage for large and small construction activities • Submit plans and obtain local permits • Construct and install BMPs as specified by plans • Maintain all BMPs throughout construction • Make necessary changes to SWPPP • Maintain inspection log that notes deficiencies and corrective actions • Remove all temporary BMPs after final stabilization • Submit NOT (for large construction activities) Important Points] • Generic developers' /contractors' responsibilities include submitting plans and obtaining all necessary permits. This process will vary depending on the different cities' requirements. • Fulfilling permit conditions throughout construction is the deve lope rs'(owne rs')/ope rators' most important responsibility. It includes: ♦ proper installation, inspection and maintenance of all BMPs throughout: construction. ♦ record keeping which requires maintenance of SWPPP, reflecting all site changes to the SWPPP and providing necessary certification within the required time period, as well as maintaining an inspection log that notes deficiencies and corrective actions. • Developers(owners) /contractors (not the inspectors) are primarily responsible for inspecting BMPs to ensure that they work; inspectors only confirm compliance. 22 MS4 Inspector's Responsibilities • Enforce all applicable local (MS4) ordinances • Advise TPDES permittees of identified deficiencies related to compliance with the Construction General Permit • Assess site conditions and understand the developer's SWPPP • Possess technical competency to determine if BMPs are properly installed and effective for the site conditions • Determine if the SWPPP is being kept up to date as site conditions change and deficiencies are identified • Check that BMPs are properly maintained • Take appropriate enforcement actions against violators including referral to TCEQ in accordance with local (MS4) procedures if necessary Important Points] • Inspector needs to understand that an effective inspection program requires: ♦ Appropriate technical competency. ♦ A focus on winning cooperation /bargaining enforcement. ♦ Playing a diagnostic and enforcement role. ♦ Fairness and a creative problem - solving attitude in helping site personnel meet permit requirements. ♦ Clear communication channels between the enforcer and developers /contractors. ♦ An understanding that the degree of installation and maintenance compliance is directly proportional to the frequency and duration of inspection. • Inspectors only confirm compliance; it is the developers' (owners') /operators' responsibility to inspect and maintain all BMPs. 23 1VIS4 Inspector Checklist • During initial inspection, inspector needs to understand site conditions: ♦ Erosion and sediment control plan xk ♦ BMP installation ♦ Erodibility of soils ♦ Critical site area ♦ Potential source areas on site ♦ Presence and quality of existing vegetation ♦ Existing and proposed drainage patterns ♦ Climatic conditions during construction ♦ Construction sequencing Important Points • Generic Inspection Checklist and Schedule for typical E &S controls ♦ All required permits and plans should be in order. ♦ Erodibility of soils: What type of soils are on site? Physical and chemical characteristics of soils? ♦ Are BMPs properly installed? ♦ Critical site area: Are there any critical site areas that may require special considerations such as wetlands or creeks? ♦ Note potential source areas such as the location of construction staging, material /chemical storage, and waste disposal areas. ♦ Note the presence and quality of existing vegetation: Is there any existing vegetation that could be utilized for on -site erosion and sedimentation control program? ♦ Existing drainage pattern: Can the existing drainage patterns be modified to prevent run -on and' reduce runoff from exposed areas? If there is a spill, what is the most effective way to contain the pollutants on site? ♦ Climatic conditions during construction: During wet seasons, more inspection may be necessary and BMPs may require more maintenance. ♦ Construction sequencing: Does it make sense? Will it minimize site exposure? 24 M[S4 Inspector Checklist • During follow -up inspections, observe overall conditions: ♦ Signs of good housekeeping practices should be evident ♦ Signs of erosion and sedimentation should be noted ♦ BMPs should be properly installed ♦ BMPs :should be maintained based on schedule and all site changes should be reflected in SWPPP ♦ Corrective measures required by previous inspections should have been implemented ♦ Sediments collected from regular maintenance efforts will need to be handled appropriately and not contribute to additional sedimentation problems ♦ Operator inspection log complete Important Point;] • BMP implementation and maintenance: Are BMPs installed in a timely manner to meet the permit requirements and as specified by the SWPPP? Are the BMPs properly maintained? OV N\WWOIN - (�i OV" !QW, W� 25 MS4 Inspector Checklist • Miscellaneous ♦ Inspection immediately after a significant rain event will allow inspector to identify ineffective erosion and sedimentation controls ♦ Intermediate inspection between rain events will allow inspector to observe maintenance effort ♦ Work with operator's site representative and initiate enforcement actions if necessary ♦ After construction is completed, inspector continues regular inspections until site is permanently stabilized and temporary measures and accumulated sediment are removed Important Points] 26 Part 2: Storm Water Best Management Practices for Construction Activities Controlling Pollution From Construction • Best Management Practices (BMPs) ♦ Effective and practical techniques or combination of techniques used to reduce pollution. • Pollution management using BMPs ♦ Preventive BMPs ♦ Treatment (remedial) BMPs ♦ Combination of preventive and treatment BMPs Important Points] • Best Management Practices are a group of techniques proven to be effective in reducing and controlling storm water pollution. • Three basic classes of BMPs: ♦ Preventive, measures, ♦ Treatment measures, and ♦ Combination of preventive and treatment measures. • Examples of different BMPs: ♦ Preventative -- ground cover, diversion dike. ♦ Treatment -- silt fence, sediment pond. 27 Preventive vs. Treatment BMPs • It is often more cost - effective to prevent construction site erosion than to treat and remove pollutants from runoff. Low High Limiting disturbed areas through phasing Protecting disturbed areas through 12 0 mulching and reve etation >_ Diversion around disturbed areas w ~ Sediment removal through detention Structural controls to treat flow High Low Important Points] • Leaving cover on -site as long as possible (and restoring it as soon as possible) reduces costs by: ♦ Reducing amount of runoff, ♦ Reducing erosion, and ♦ Lowering need for treatment BMPs. • Limit disturbance on areas that do not contribute to the final development: ♦ Protect areas that are beyond the limits of construction as specified, ♦ Minimize construction staging area, and ♦ Utilize effective construction sequencing, e.g. construct parking lots first and stage building construction from the parking lot. • Do not disturb off -site areas without permit/agreement and, if used, stabilize disturbed areas before leaving site. 28 Controlling Erosion • Preventive Practices: ♦ Vegetatlive ground protection / ground stabilization ♦ Non - vegetative ground protection ♦ Diversion • Treatment (Remedial) Practices: ♦ Trap and filter flow ♦ Trap and hold flow to allow settling Important Points] 29 Preventive Practices • Vegetative ground protection ♦ Vegetative ground protection (VGP) is the most effective way of preventing erosion. ♦ VGP can be permanent or temporary. ♦ Provide vegetative ground protection by: • Staging construction to retain existing vegetative cover and minimize exposed ground. • Using temporary and permanent VGP such as mulch and mats with seeding. Important Point:] • Vegetative ground protection prevents erosion by: ♦ Shielding the soil surface from the direct erosion impact of raindrops; ♦ Retaining water by improving the soil's water storage porosity and capacity so more water can infiltrate into the ground; ♦ Reducing runoff energy by slowing the runoff and allowing the sediment 'to drop out or deposit; and ♦ Physically holding the soil in place. • Provide VGP by: ♦ Preserving existing ground covers by establishing limits of construction and identified vegetative buffer and tree protection areas. ♦ Staging construction to retain existing vegetative cover and minimize exposed ground. ♦ Using temporary and permanent VGP such as temporary seeding, permanent seeding, mulch and seed, mulch /mat (mulch /mat provides protection while vegetation becomes established), and sodding (sodding provides immediate permanent stabilization). 30 Preventive Practices • Non - vegetative ground protection: ♦ Non - vegetative measures are also used to protect ground from erosive forces. • Diversion: ♦ Diversions are placed to divert the erosive forces away from areas that are disturbed and most prone to erosion. Important Points] • Examples of non - vegetative measures are rip rap at outlets and pipe slope drain. • Exposed ground can be stabilized by lime stabilization, which is quite common in North Texas areas for soils with high plastic limits (clay). However, runoff firom lime stabilized areas may adversely impact the pH of runoff, which could be toxic to aquatic life. Precautions for lime stabilized areas include: ♦ Place lime in stages to ensure that lime placed can be thoroughly mixed. ♦ If phasing is impractical, curing seal will be necessary. Place curing seal based on manufacturer's specifications. ♦ Diversions such as dike and interceptor swales are used to control and reduce the potential to carry lime offsite. • Diversion - dikes, drains, swales used to route flows around disturbed areas. 31 Important Points] 32 Treatment/Remedial Practices • Trap and filter flow: ♦ Filter barriers are used to filter sediment -laden flow. • Trap and hold flow to allow settling of sediment: ♦ Different methods are used to hold sediment -laden runoff for settling. Important Points] • Perimeter controls include silt fences and straw bales; inlet protection uses silt fences or a combination of wire mesh and gravel filter barrier. • Trapping and holding flow allows settling of sediment. • Different methods are used to hold sediment -laden runoff for settling: s� Check dams, stone outlet sediment traps, temporary sediment tanks and :sediment basins. • Settling basins provide a higher rate of efficiency in removing sediments when compared to other treatment practices. 33 Combination of Preventive and Treatment BMPs • Preventive measures are the most effective method. However, construction activities inevitably create conditions where erosion and sedimentation occur. 4 most practical solution Design a site - specific solution that uses a combination of preventive and treatment (remedial) BMPs. Important Points] • As part of a site - specific solution, consider integrating the following construction sequencing techniques: ♦ Following a specified work sequence that coordinates the timing of land- disturbing activities, logistics of equipment access and installation of control measures is perhaps one of the most important steps in implementing a successful program in controlling erosion during construction. ♦ The removal of surface ground cover leaves a site vulnerable to accelerated erosion. Construction procedures that limit land clearing, provide the timely installation of erosion and sedimentation controls, and restore protective cover quickly can significantly reduce the erosion potential of a site. ♦ The construction sequence is an orderly listing of all major land- disturbing activities together with the necessary erosion and sedimentation control measures planned for a project. This type of schedule guides the contractor on work to be done before other work is started so that serious erosion and sedimentation problems can be avoided. 34 Screening E &S Control BMPs for Construction Sites ENTRANCE AND EXITS MMUM11100- AREAS EXPOSED MORE THAN 14 WMEN1111111- DAYS DURING CONSTRUCTION EXPOSED AREAS WITH RUN -ON I -_ FROM UPSTREAM OR RUNOFF FROM SITE TO CRITICAL AREAS FLOW WITH HIGH VELOCITY 1 ­1111110- EXISTING AND NEW STORM INLETS RECEIVING FLOW RUNOFF WITH HIGH SEDIMENT I .a.- STABILIZED CONSTRUCTION ENTRANCE PERMANENT REMOVE TEMP. CONSTRUCTION COMPLETION STABILIZATION MEASURES Important Points] • It is important to recognize that a BMP works for a specific set of circumstances and not in all situations. • Intermediate maintenance, including sediment removal, is required to keep BMPs functional. • Inspection of BMPs after rainfall of 0.5" rain or greater is the best way to determine the effectiveness of implemented BMPs; schedule maintenance and corrective measures as necessary. • BMPs and accumulated sediment must be removed at the completion of construction. 35 Silt Fence • Initial Inspection: ♦ Geotextile should meet stated technical specifications. ♦ Geotextile should be secured and supported by posts. ♦ Geotextile should be embedded in trench to prevent any bypass of runoff under the silt fence. ♦ Silt fence should be placed on contour to receive only sheet flow as specified by the SWPPP. ♦ End of silt fence should be turned upslope such that runoff does not flow around silt fence. Important Points] • Silt fence: ♦ A silt fence reduces the velocity of flow, allows deposition, and retains sediment. It consists of a permeable barrier erected on small disturbed areas to capture sediment from sheet flow. It is made of filter fabric buried at the bottom, stretched, and supported by posts. ♦ Because silt fences are not designed to withstand high heads, the drainage area must be restricted. Silt fences should be placed along contour lines such that they do not receive concentrated flow and water depth does not exceed 1.5 feet at any point. • Straw /hay bale barrier ♦ Sometimes straw /hay bales are used instead of silt fences. These are temporary barriers consisting of a row of entrenched and anchored straw /hay bales erected on small disturbed areas to capture sediment from sheet flow. ♦ Straw /hay bale barriers also reduce the velocity of flow, allow deposition, and retain sediment. They are not designed to receive concentrated flows. ♦ As a sediment barrier, straw /hay bales are less effective than silt fences and they require more maintenance. They have a design life of 3 months or less. Do not install straw bale barriers across streams, ditches, or where flows are concentrated. 36 Silt Fence • Follow -up Inspection: ♦ Observe signs of sedimentation downstream of the silt fence. ♦ Silt fence should remain secured and the geotextile should remain embedded with no gaps. ♦ Geotextile that is clogged with sediment will need to be cleaned or replaced with new fabrics if necessary. ♦ Silt buildup in excess of 6 inches high behind the fence will need to be cleared. Important Points] 37 a ar ' M \`\. \ \\ oil VON I -a • • Silt Fence Stabilized Construction Entrance • Initial Inspection: ♦ Entrance must be placed at location specified by plan or as needed according to site conditions. ♦ Crushed rocks or concrete must meet minimum 3- to 5 -inch diameter requirements and not be placed directly on the ground but on top of the filter fabric. ♦ Entrance must meet both minimum and site - specific length, width and 6 -inch thickness requirements. Important Points] • Preferred location is at the high point of the site away from storm water ponding area. 39 Stabilized Construction Entrance • Follow-up Inspection: ♦ Look for signs of off -site sediments on paved areas: • Tracked sediments need to be removed. • Identify the reason. Is the construction entrance serving its intended purpose at the specified location? ♦ New dressing of rock/concrete is necessary when: • Gaps between rocks /concrete are filled with sediment, or • Rock/concrete is crushed to less than 3 -inch diameter. Important Points] • When a stabilized construction entrance is working properly, sediment is being deposited. The sediment trapped by the entrance needs to be removed and properly disposed of frequently. • It may be necessary to install a water tap for wash downs and wash rack to further reduce sediment tracking in abutting streets. 40 DIVERSION RIDGE REQUIRED WHERE GRADE EXCEEDS 27. 2 X OR GREATER SEDIMENT BARRIER (STRAW BALE TYPE SHOWN) \ SUPPLY WATER TO WASH WHEELS IF NECESSARY, FLOW 1 - -�- �- q O C4 A Q A. a Z H rn p W SECTION A - A NOTE: / SPILLWAY USE STRAW BALES OR jr�ERDBAAGS-ROVED ME THODS TO HNELIZE RUNOFF TO BASIN AS /REQUIRED. � I fww ,� . � • . /� • .�•� iii �;�``• : • �,�"• ; • •;� • . • "�;. ,�. COURSE ��•= :� A AGGREGATE MIN. r THICK !��'�• _ • .'. �,� DIVERSION RIDGE 50' MIN. PLAN Stabilized Construction Entrance Temporary Vegetative Ground Protection • Initial Inspection: ♦ Temporary ground protection should be implemented in locations as specified by the plan (SWPPP). ♦ Mulch should be used for areas that have just been seeded or disturbed areas during non - growing season. ♦ Temporary stabilization is required for all disturbed areas, including off -site material storage areas. • Follow-up Inspection: ♦ Thin and bare spots need to be reapplied or revegetated. Important Points] For any disturbed areas that will remain for more than 21 days, temporary stabilization is required. Use either mulch, temporary seeding or a combination of mulch /temporary seedings. Vegetation needs to be established by the 14th day if disturbed areas are to remain more than 21 days. Mulching: • Mulch is the most effective, practical means of controlling erosion on disturbed areas before establishing vegetation. Mulch protects the soil surface, reduces runoff velocity, increases infiltration, slows soil moisture loss, helps prevent soil crusting and sealing, moderates soil temperatures, and improves the microclimate for seed germination. ♦ Organic mulch such as straw, wood chips, and shredded bark are effective for general use where vegetation is to be established. In recent years, a variety of mats and fabrics have been developed that make effective mulches for use in critical areas such as waterways and channels. Various types of tacking and netting materials are used to anchor organic mulches. Netting is generally not effective when used alone. Temporary seedings: ♦ Annual plants that are adapted to site conditions and that sprout and grow rapidly should be used for temporary plantings. Proper seedbed preparation and the use of quality seed are also important. ♦ Because temporary seedings provide protective cover for less than one year, areas must be reseeded annually or planted with perennial vegetation. ♦ Temporary seeding is used to protect earthen sediment control practices and to stabilize denuded areas that will not be brought to final grade for several weeks or months. Temporary seeding can provide a nurse crop for permanent vegetation, provide residue for soil protection and seedbed preparation, and help prevent dust production during construction. 42 Diversion Dike • Initial Inspection: ♦ Diversion dike should be placed as specified by the SWPPP prior to any site disturbance. ♦ Diversion dike should be properly compacted using materials clear of vegetation. ♦ Diversion dike should meet accepted side slope, width and height criteria. • Follow -up Inspection: ♦ Vegetation needs to be established by the 14th day if dike is to remain more than 21 days. ♦ Any break in the dike will need to be repaired and re- stabilized. ♦ Silt buildup will need to be removed. Important Points] • Diversions are among the most effective and least costly practices for controlling erosion and sedimentation. They can be permanent or temporary and can serve special purposes such as perimeter protection. • Diversions may control runoff above steep slopes, across long slopes, below steep grades, and around buildings or other areas subject to damage from runoff. The capacity of the diversion should be based on the runoff characteristics of the completed site and the potential damage from runoff after development. • It is important that diversions be designed, constructed, and maintained properly since they concentrate flow and increase erosion potential if failure occurs. Outlets for diversions must be stable for the expected flow and reinforced before the diversion is installed. 43 DISCHARGE ONTO A STABILIZED OUTLET CROSS - SECTION iRUNOFF FLOW POSMVE DRAINAGE PLAN V" N.T.S. 3:1 SLOPE 24' MIN. DIKE TO BE PLACED IN Ir LIFTS. COMPACTED OR FLATTER TO 95X STD. PROCTOR DENSITY FLOW .�-- -- lfr MIN. 7' -0' 1AIN. STABILIZATION. IF REQUIRED SHALL BE EXISTING GROUND -r THICK LAYER OF CRUSHED STONE OR HIGH VELOCITY EROSION CONTROL MATTING CROSS SECTION N.T.S. Diversion Dike Interceptor Swale • Initial Inspection: ♦ Swale should be placed as specified by the SWPPP. ♦ Swale should be properly stabilized. ♦ Swale should meet accepted depth, width, and side slope criteria. • Follow -up Inspection: ♦ Areas that show signs of erosion will need to be re- stabilized. ♦ Damaged sections and ponding areas will need to be repaired. ♦ Sediments and debris in the swales will need to be cleared. Important Points] • Swale ♦ Until swale has been stabilized, silt -laden runoff should be discharged to a treatment barrier. ♦ Swale must maintain a positive grade. ♦ Swale should be discharged to an acceptable outlet -- either a stabilized area for diverted run -on or sediment trap for sediment -laden flow. ♦ Areas that show signs of erosion need to be restabilized. In addition, the effectiveness of the cover materials should be evaluated. r•Al CROSS SECTION STONE STABILIZATION MIN. T THICKNESS OR EROSION CONTROL MAT IS REQUIRED WHEN VELOCITIES EXCEED 6 FPS OR SLOPE -- EXCEEDS 2.0% PLAN Vm N.T.S. CHANNEL WIDTH (PER PLANS) 3:1 SLOPE OR FLATTER --� 1.5' DESIGN WATER SURFACE ELEVATION CROSS SECTION N.T.S. Interceptor Swale Energy Dissipator/ Stone RiDrau • Initial Inspection: ♦ Riprap should be placed as specified by the SW PPP and meet the criteria for width, length, and stone sizes. ♦ Riprap layer consisting of a mixture of stone sizes, as specified, is more stable. ♦ Stones should not be placed directly on the soil surface but on top of a filter fabric layer. • Follow -up Inspection: ♦ Signs of erosion may indicate riprap is inadequate. ♦ Remove sediments that are built up. Important Points] 47 MATERIAL ELEVATION THICKNESS ('d') - 1.5 x MAX ROCK DIAMETER (I' MIN.) _I 12' MIN. 'D' um— SECTION La - 4.5 x 'D' MIN. 'D' = PIPE DIAMETER PLAN Energy Dissipator / Stone Riprap 4.0 x '0' MIN. Inlet Protection • Inlet protection is used in paved or unpaved areas: ♦ Silt fencing or hay bales in unpaved areas. ♦ Wire mesh and gravel filter barrier in paved areas. • Initial Inspection: ♦ Inlet protection is placed as specified by the SWPPP. ♦ These may create ponding; therefore, traff ic and pedestrian safety should be considered. ♦ Overflow /relief for flow exceeding the inlet protection capacity should be provided. Important Points • There are many different types of drainage inlets such as curb and grate inlets. Inlet protection for different types of inlets varies. • Inlet protection is necessary for both existing and proposed inlets that are receiving sediment -laden runoff. Filter barriers (geotextile and gravel) shall meet accepted criteria. • Inlet protection installed on sloping streets /areas does not allow ponding; it merely blocks water from entering the storm sewer system. • To make sure that inlet protection does not cause excessive ponding /flooding, it should provide overflow relief. An example of overflow relief is the gap at the top of the curb inlet protection. 'Y' ON' "� u` v�+ 49 Inlet Protection • Follow -up Inspection: ♦ Barrier around the inlet structure must be continuous to prevent flow from bypassing. ♦ Inlet protection using geotextile should receive same follow - up inspection as silt fence. ♦ If inlet protection using gravel /stone barrier is clogged, stone /gravel will need to be pulled to clear and remove sediment. ♦ Damage from normal construction activities such as truck traffic should be repaired as soon as possible. Important Points WX BACK OF SIDEWALK r- A -- CATCH BASIN BACK OF CURB CURB INLET 2X4 WOOD STUD CONCRETE BLOCK WIRE SCREEN OR� �vwo` -1w1Uk- 71Q1°e: FILTER FABRIC A \ CONCRETE BLOCK 314 t DRAIN GRAVEL PLAN VIEW �� PONDING HEIGHT / OVERFLOW �� CONCRETE BLOCK umm `WIRE SCREEN OR CATCH BASIN FILTER FABRIC PLACED OVER VERTICAL \�-' 2X4 WOOD STUD FACE TO PREVENT GRAVEL PLACED THROUGH FROM GETTING THROUGH THE HOLES OF SPACER BLOCK ON BOTH END TO KEEP BLOCKS IN PLACE SECTION A - A Curb Inlet Protection it PLAN VIEW ATTACH FILTER SECURILY • FABRIC WOOD FRAME. OVERLAPPING .- FRAME NECESSARY FABRIC TO NEXT STAKE FOR STABUTY PONDING HT. 2x4 WOOD FRAME 4 SIDES OF DROP INLET 0 x II�TRENCHDggINCK�LLED WITH COMPACTED EARTH SECTION A -A Silt Fence Drop Inlet Sediment Barrier Wnnn CTAWrr nn ME DRAIN GRATE LESS THAI 5% SLOPE STRAW BALES TIGHTLY STACKED OR ,ET CORNERS :HOWN. PLAN VIEW PONDING HEIGHT STRAW Ln— — — — ---a i DROP INLET V U SECTION A -A (STRAW BALES STAKED WITH 2 STAKES PER BALE) GRAVEL BACKFlLL GRAVEL BACKFILL EMBED STRAW BALE C MIN. INTO SOIL. Straw Bale /Gravel Dro p Inlet Sediment Barrier GRAVEL (12" MIN. DEPTH) 18` MIN RUNOFF WATER WITH SEDIMENT SEDIMENT 111111= Ii ►III =: _ 1111= ililli= FILTERED WATER Drop Inlet Protection with Wire Mesh and Gravel Check Dams • Check dams are barriers of rock or sand bags placed across a drainage swale or ditch. ♦ They reduce the velocity of small flows and allow sediment to settle„ • Initial Inspection: ♦ Check dams should be placed as specified by the SWPPP and used only in conjunction with other BMPs. ♦ They should be placed in series and anchored, and should meet accepted height and spacing criteria. ♦ They are designed for small flows; major flows should be allowed to pass to avoid major flooding upstream. Important Points • Check dams are used to reduce gullying /erosion in the bottom of small channels. They are temporary expedient practices to reduce channel erosion until permanent stabilization measures can be installed. These small channel blocks serve to restrict the velocity of flow by reducing the cross - sectional area of the channel at a series of selected points. • Check dams are usually made of stone. The center section must be lower than the edges. Space the dams so that the toe of the upstream dam is at the same elevation as the top of the downstream dam. Ensure that overflow areas along the channel are resistant to erosion from out -of -bank flow caused by the check dams. Restrict the drainage area above the lowest dam to 5 acres or less. 55 Check Dams • Follow -up Inspection: ♦ Replace and re- anchor check dam as necessary. ♦ Remove built up sediments to prevent flushing of sediments by largo flow. ♦ Make sure that overflow areas from the overflow caused by the check dams do not show signs of erosion. Important Points] 56 POINT 'X' SHOULD BE�_ ABOVE POINT 'Y' t- 2 • • lim. . . u THE DISTANCE SUCH THAT POINTS 'A' AND 'B' ARE OF EQUAL ELEVATION. Check Dams Sediment Tank • A sediment tank is a large truck - mounted tank used to treat sediment -laden water to provide for sedimentation and filtration. • Initial Inspection: ♦ Use in sump locations where other BMPs are not practical. ♦ Tank should not have sediment beyond 1/3 tank capacity. • Follow -up Inspection: ♦ Insure adequate treatment is provided prior to discharge. ♦ Tank sediments should be disposed of properly. Important Points • This practice works well with utility construction in confined areas, for example, a trench that is filled with sediment -laden rain water or groundwater, or excavation in a highly developed area (tank farm). V &X&Y) 58 55 GAL DRUMS, OR SIMILAR WELDED END lb END 3'0 INTAKE FROM SUMP PUMP 2'x4' CRADLE ENDS OF BARRELS CUT TO ACT AS A BAFFLES (TYP.) =1 ELEVATION 12' (APPRO)L) CLEANOUT SLOT CUT OUT (INTERIOR WALL ONLY) SECTION A -A APPROX 3/4 4 BARREL END TO ACT AS BAFFLE Portable Sediment Tank Stone Outlet Sediment Trap • A stone outlet sediment trap is a small ponding area formed in a depressed area where a stone embankment or gabion is placed to act as an outlet. • Initial Inspection: ♦ Check to ensure that the trap is installed as specified by the SWPPP (location, size, depth, and embankment). Important Points • This temporary device can be used in areas for 18 months or less. 04 Stone Outlet Sediment Trap • Follow -up Inspection ♦ Inspect to make sure that trap is not clogged: • Stones may need to be pulled to remove sediment between them. ♦ Remove buildup or sediments when buildup is beyond 1/3 capacity of the trap. ♦ Sediment removed should be disposed of properly. Important Points] 61 i b GEOTEME COVERED FILTER STONE CORE W RIP RAP 3 �+ 1 EXCAVATION. IF NECESSARY FOR STORAGE. 1800 CF /AC.. MINIMUM FLOW CROSS- SECTION OF STONE OUTLET SEDIMENT TRAP EXISTING GROUND 3 1� Stone Outlet Sediment Trap Sediment Basin • Sediment basins can be the most effective treatment practice in removing sediment from runoff. • Initial Inspection: ♦ Check to ensure that the basin is installed as specified by the SW'PPP (location, size depth, embankment, spillway, and outlet). ♦ The discharge point of the outlet pipe should be stabilized with riprap and no additional erosion should be created. ♦ Basin embankments must be stabilized to prevent erosion. Important Points] • Basins are located to capture sediment from as much of the disturbed area of the site as possible and should be installed before clearing and grading begin. Ease of basin cleanout and spoil disposal should be considered in site selection. The embankment should be well compacted and vegetated. • The rate of removal depends on the sediment type. Sands are relatively easy but clay and silts take a lot longer to settle out. The trap efficiency of the sediment pond will depend on how long and how much runoff is detained. To increase the trap efficiency, the basin should have the maximum surface area possible, and sediment should enter the basin as far from the outlet as possible. • Sediment basins should not be constructed in live streams or where failure might cause loss of life or serious property damage. 63 Sediment Basin • Follow -up Inspection: ♦ Inspect to make sure that outlet structure is not clogged and remove debris. ♦ Remove buildup of sediments when buildup is greater than 1/5 capacity of the basin. ♦ Sediment removed must be disposed of properly. ♦ Outlet pipe should not create any erosion downstream of sediment basin. ♦ Observe riprap at discharge for signs of sedimentation to provide an indication of the effectiveness of the sediment basin. ♦ Check for basin embankment stabilization. Important Points M Good Housekeeping • Housekeeping practices observed during inspection will indicate overall E &S control effort: ♦ Spoil piles, fill areas, and unprotected exposed ground need erosion protection ♦ Construction sites require: • waste collection and disposal • ways to handle concrete washouts • proper storage for chemicals and fuels • containment for runoff from lime stabilized areas Important Points will Appendix 1 Inspection Forms F- Q a OC O LL Z O H V W CL z a D N L c 0 E O C N O a CL ml a� a� L O O O O Z Z Z Z: c O 0 o Z 16 N `m «s a � a a a c� X m X z a o So C/5 w U) 0 J a m ac_ z Q O o 0 � U9 Ca G CX. E mo X t� O Q O U �> Z ca � a) cA m U) o _ w @ a a v N H d U d Lu rn c .Q CO o Y a) N c 0 U U CO `m CL 3 'D Q) O U m y a a) ca ca m (D c O E (, E U) N O m p 7 a) O E Z U H a Q �° ¢ O M a) Z: N i (c$ co U Q U ti ml a� a� L O I a7 X X X X So ac_ X fl o c 0 U CO CL m y a a) m (D c O E (, E E N O m p 7 U O E Z U H a Q �° ¢ O ml a� a� L Q N H cr Q IL O LL z LO r W a z q ns N Cl) U a) C N co a c co E (b ca a) N CD a) t C O U m Q N C a� Q N F- Ir Q d O N co 3 CD a� U c O U CD a _ c co CD co c a� E a� co c co E a) Z5 co 3 a> rn co O m _ rn c _ co co $D co a> O y c m E Q Q d co �L ca E C a> U fo C O U _ N C O U 3 N co as U a) CL Cl) C a) O z a� L m N H Q IL Q O LL Z O F- U W CL m z aY U) a) U C «s a c as E co as m (D co a 3 0 0 U- C: 0 U CL y C m N H Q d. N E E a V . c d s I� `m w c a Q ;c !a: d z z z z z z z z a c a Ch CO) a a a a a G a. +4 d v_ D o ;c O v O 4 N Appendix 2 Quizzes Quiz 1 1. T / F The best way to control sediment is to reduce erosion. 2. T / F It is generally more cost - effective to prevent construction site erosion than to treat and remove sediments from muddy water. 3. T / F Sediment is the only potential impact from construction sites. 4. T / F Silt fencing is very effective; therefore, it should be used on all construction sites. 5. T / F Vegetative stabilization is the most effective type of control. 6. T / F Erosion can largely be prevented on construction sites by using the appropriate preventive BMPs. 7. T / F Erosion controls are mostly preventive BMPs and sedimentation controls are mostly treatment BMPs. 8. T / F The most practical solution to erosion and sedimentation is a combination of preventive and treatment BMPs. 9. T / F Storm water is the only force that contributes to erosion and sedimentation. 10. T / F It is the developers'(owners') /operators' responsibility to inspect and maintain BMPs. Inspectors only confirm compliance. 11. Name two reasons, other than water pollution, why sediment from construction sites is a problem. 12. Four factors that determine the rate of erosion: Quiz 2 1. T / F A temporary construction entrance is installed to trap sediment from construction vehicles. 2. T / F To stop runoff from flowing around a silt fence, the ends of the silt fence are turned down slope. 3. T / F Inadequate maintenance is often cited as one of the major factors influencing the poor effectiveness of BMPs. 4. T / F Check dams are not effective for catching sediment but can slow flow velocity and reduce channel erosion. 5. T / F When inlet protection is used in paved areas, it is important to consider the effects of ponding runoff on traffic and safety issues. 6. T / F Straw /hay bales are as effective as a silt fence. 7. T / F Sediment basins can be the most effective sediment removal structures. 8. T / F The design life of a straw /hay bale is more than 3 months. 9. T / F It is important to install a silt fence along a contour line. 10. T / F Straw /hay bales can be used as check dams in channels. 11. T / F The most effective way to provide ground cover is to use riprap. 12. T / F Inspecting erosion and sediment controls immediately after a rainfall event will provide good indications on the performance of erosion and sedimentation controls on a construction site. 14. T / F Riprap is used at outlet discharge points to reduce the velocity of flow and to reduce erosion in channel areas. 15. T / F When installing a silt fence, it is important to embed the filter fabric in trenches to prevent any bypass of runoff under the silt fence. 16. T / F After the site is permanently stabilized, it is very important to keep the silt fence on site as a secondary measure to capture additional sediments. 17. T / F Place crushed rocks directly on the ground when installing a temporary construction entrance. 18. T / F During winter, straw or hay mulch will be the best form of temporary ground protection. Quiz 2 19. T / F Construction sequence does not have any impact on the installation of erosion and sedimentation controls. 20. T / F Built up sediments cleared from sedimentation controls can be disposed on -site when they are permanently stabilized and will not contribute to sediment off -site. 21. Two examples of Spill Prevention and Response: 22. Two examples of Material Storage and Handling: 23. Two examples of Waste Management and Disposal: Quiz 3 1. T / F All construction sites require grading permits and SWPPPs. 2. T / F When an NPDES permit is required, submit the NOI first and then prepare a SWPPP. 3. T / F Erosion and sediment control is the only concern for SWPPPs. 4. T / F Inspectors' major responsibility is to issue stop work orders to violators. 5. T / F For construction sites that submitted an NOI, both the NOI and the SWPPP will have to be made available on site for inspection. 6. T / F Whenever there are any changes to site conditions and operations, it is the inspector's responsibility to update the SWPPP within 7 days. 7. T / F Sediment is the only potential pollutant from construction sites. 8. T / F A construction site that is more than 5 acres in size is defined as an industrial activity that will be regulated by a general NPDES permit. 9. T / F Debris from a construction site should be buried on site. 10. T / F Erosion and sedimentation controls will not be necessary when lime is used to stabilize a construction site. 11. T / F During dry seasons, water can be used to limit wind erosion. 12. T / F The operator must perform inspections of BMPs at least once every two weeks and within 24 hours after a storm of 0.5 -inch or greater. 13. List the four major responsibilities of inspectors: 14. List the four major responsibilities of developers(owner') /operators: Appendix 3 Glossary Glossary Of Storm Water Management Terminology AST Above - ground storage tank. Backfill Compacted soil material used to bring an area to grade so that drainage will flow away from the site. Baseline General Permit A storm water permit (issued under the NPDES program) intended to cover the majority of storm water discharges associated with industrial activities. Best Management Practices (BMPs) Schedule of activities, prohibitions or practices, maintenance procedures, and other management practices devices designed to prevent or educe t e ton poll of waters by preventing pollutants from entering storm waters or by directing the flow of such waters. BMPs also include treatment requirements, operating procedures, and practices to control facility site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. Binding agent / tacking agent Any chemical or mechanical method used to secure mulch to keep it from blowing or washing away. Biodegradable Having the ability to break down or decompose under natural conditions and processes. Bypass Intentional diversion of waste streams from an Y portion of a treatment facility. By- product Material, other than the principal product, that is generated as a consequence of an industrial process. Calculated drainage area The area of land that is vulnerable to storm water runoff and sedimentation that will impact planned perimeter controls. CERCLA Comprehensive Environmental Response, Compensation, and Liability Act; often referred to as "Superfund." Check dams Small, temporary dams constructed across a drainage swale or ditch used to dissipate the velocity of the storm water drainage. Clean Water Act (CWA) Federal law regulating the discharge of water -bome pollutants into surface waters. Also referred to as the Federal Water Pollution Control Act or Federal Water Pollution Control Act Amendments of 1972. Code of Federal Regulations Compendium of official Federal Regulations. Notation indicates (CFR) volume number, part and section of the code, as in 40 CFR 122.26. Glossary — Page 1 Glossary Of Storm Water Management Terminology (Continued) Combined storm water sewer A conveyance system which conveys storm waters and other system waste waters together. Concentrated storm water flow Runoff flowing in a defined channel or drainageway. vegetation worn down due to impacts from the elements or Conduit Any channel or pipe for transporting the flow of Detention water. Contaminant/contamination An unwanted and non - beneficial substance. Conveyance Any natural or manmade channel, ditch, culvert, pipe, conduit or Diversion dike similar device in which concentrated water flows. Conveyance system A system of interconnected open, closed, or pressurized flow manmade or natural flow conveyance structures, pipes, channels, drains, and similar devices to transport waste, storm, Dust control or similar waters. Culvert A covered channel or a large- diameter pipe that directs water Environmental Protection Agency (EPA) flow below the ground level. Curb Manmade ground level structure of small height but usually of considerable length used to confine or contain liquids on the ground. Denuded Land stripped of vegetation such as grass, or land that has had vegetation worn down due to impacts from the elements or humans. Detention The temporary holding of runoff in a basin. Discharge A release or flow of storm water or other substance from a conveyance or storage container. Diversion dike 'Also known as an earth berm; a perimeter erosion and sedimentation control, usually a temporary ridge of compacted earth, which is stabilized with seed and mulch. Dust control The process of spraying water on denuded land areas to reduce wind erosion. Environmental Protection Agency (EPA) Primary federal agency responsible for enforcement of federal laws protecting the environment. Glossary - Page 2 Glossary Of Storm Water Management Terminology (Continued) Erosion The wearing away of land surface by wind or water. Erosion occurs naturally from weather or runoff but can be intensified by land- clearing practices related to farming, residential or industrial development, road building, or timber - cutting. Exempt nonstorm water Nonstorm waters which can be legally discharged with storm waters without an NPDES permit. Under federal storm water discharge regulations, the following nonstorm waters are exempt nonstorm waters: - Discharges from fire fighting activities - Fire hydrant flushings - Potable waters, including waterline flushings - Irrigation drainage - Lawn watering - Uncontaminated groundwater - Foundation or footing drainage which is not contaminated with process materials - Discharges from springs - Routine exterior building washdown waters which do not have detergents in them - Pavement wash waters from areas where spills or leaks of toxic or hazardous materials have not occurred and in which detergents are not used - Air conditioning condensate Filter fabric A synthetic, woven or nonwoven fabric used for perimeter sediment control and for soil separation such as construction entrances. Filter strip Usually long, relatively narrow area of undisturbed or planted vegetation used to retard or collect sediment for the protection of watercourses, reservoirs, or adjacent properties. Gabion stone Six- to eight -inch well - graded rock, generally placed in wire baskets for stream bank erosion control; also used for gravel outlets for temporary sediment traps. Gravel filter Strategically sized and installed rock used to regulate the flow of water discharging from a temporary sediment trap. Grommets Large metal or plastic staples used to secure flexible tubing to a sloping area; primarily used for temporary slope drains. Glossary - Page 3 Glossary Of Storm Water Management Terminology (Continued) Hazardous substance Any material that poses a threat to human health or the environment. Hazardous substances can be toxic, corrosive, ignitable, explosive, or chemically reactive; or any named substance required by EPA to be reported if designated a quantity of the substance is spilled in the waters of the United States or if otherwise emitted into the environment. Incident The release of an undesirable substance into the Notice of Intent (NOI) environment. Inlet An entrance into a ditch, storm sewer, or other waterway. Material storage areas Onsite locations where raw materials, products, final products, by- products, or waste materials are stored. Municipal Separate Storm Sewer A separate storm water conveyance system operated by a System (MS4) municipality or other public agency. National Pollutant Discharge See the definition of "National Pollutant Discharge Elimination Elimination System ( NPDES) System" in 40 CFR 122.2 for further discussion. Federal permitting system established by the CWA and administered NPDES permit by EPA to regulate point source discharges of wastewater, process wastewater, non - contact wastewaters, storm water, and similar discharges to waters of the United States. Nonstorm water Water or any other liquid which mixes with storm water, enters a storm water conveyance system, is transported in a storm water conveyance system, or is otherwise discharged by a storm water conveyance system. Most nonstorm waters cannot be legally discharged with storm waters without being permitted (see definition of "exempt nonstorm water "). Notice of Intent (NOI) A formal, written declaration of intent to be covered by a general permit and thereby abide by the terms and conditions of such permits. NOls are submitted either to EPA or a state permitting agency. Notice of Termination (NOT) A formal, written declaration that a facility is withdrawing its coverage under a general permit after once being covered by a general permit. NOls are submitted either to EPA or a state permitting agency, justification of the withdrawal must be provided. NPDES permit An authorization, license, or equivalent control document issued by EPA or an approved state agency to implement the requirements of the NPDES program. Oil sheen A thin, glistening layer of oil on water. Glossary - Page 4 Glossary Of Storm Water Management Terminology (Continued) OiVwater separator A device, usually installed at the entrance to a drain, which removes oil and grease from water flows entering the drain. Operator Any parry associated with a construction project that meets either of the following two criteria: 1) The party that has operational control over construction plans and specifications, including the ability to make modifications to those plans and specifications; or 2) The party that has day -to -day operational control of those activities at a project that are necesssary to ensure compliance with a storm water pollution prevention plan for the site or other permit conditions. Note: There can be more than one operator for the site. Organic pollutants Substances containing carbon which may cause pollution problems in receiving streams. Organic solvents Liquid organic compounds capable of dissolving solids, gases, or liquids. Outfall The point of exit of waters from a conveyance system; at industrial facilities, the exit point for storm water conveyance systems is usually the point where storm waters leave the facility boundary. Perimeter controls E &S controls that are generally used within the boundary or perimeter of a construction site; examples are silt fences, diversion dikes, sediment traps, sediment basins. Permit An authorization, license, or equivalent control document issued by EPA or an approved State /City agency to implement the requirements of an environmental regulation; e.g., a grading or a building permit. Petroleum hydrocarbons Petroleum organic compounds that contain only carbon and hydrogen. pH Acidity or alkalinity of the discharge water. Pipe outlet sediment trap Same as the sediment trap with gravel outlet filter, but designed for drainage areas between one and three acres. Point source Any discernible, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. Glossary - Page 5 Glossary Of Storm Water Management Terminology (Continued) Pollutant Legally, any dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act), or heat discharged into water. From a practical perspective, a pollutant is any substance or mixture which after release into the environment and upon exposure to any organism will or may reasonably be anticipated to cause adverse effects in such organisms or their offspring. Pretreatment system A treatment system designed to remove gross contamination in order to increase the efficiency of the following treatment steps. Preventative Maintenance Program A schedule of inspections and testing at regular intervals intended to prevent equipment failures and deterioration. Recycle To minimize the generation of waste by recovering usable products that might otherwise become waste. Examples are the recycling of aluminum cans, wastepaper, bottles. and Reportable quantity (RQ) The quantity of a hazardous substance or oil that triggers reporting requirements under CERCLA or the CWA. If a substance is released in amounts exceeding its RQ, the release must be reported to the National Response Center, the State Emergency Response commission, and community emergency coordinators for areas likely to be affected. Residual Amount of pollutant remaining in the environment after a natural or technological process has taken place, e.g., the sludge remaining after initial wastewater treatment. Retention The holding of runoff in a basin without release except by means of evaporation, infiltration, or emergency by -pass. Retrofit The modification of storm water management systems in developed areas through the construction of wet ponds, infiltration systems, wetland plantings, stream bank stabilization, and other BMP techniques for improving water quality. A retrofit can consist of the construction of a new BMP in the developed area, the enhancement of an older storm water management structure, or a combination of improvement and new construction. Glossary - Page 6 Glossary Of Storm Water Management Terminology (Continued) Riprap A permanent, erosion - resistant ground cover of large, loose, angular stone used to dissipate the energy of storm water discharge from a pipe. Root mat A mixture of soil and plant roots that anchors the soil in place for erosion and sediment control. Runoff Storm water surface flow or other surface flow which leaves the property from which it originated. Run -on Storm water surface flow or other surface flow which enters property other than that where it originated. Sanitary sewer A system of underground pipes that carries sanitary waste or process wastewater to a treatment plant. Sanitary waste Domestic sewage. Secondary containment Structures, usually dikes or berms, surrounding tanks or other storage containers and designed to catch spilled material from the storage containers. Sediment Solid material, both mineral and organic, that is in suspension, is being transported, or has moved from its site of origin by air, water, or ice, and has come to rest on the ground's surface. Sediment basin A holding area with a controlled storm water release structure; designed for drainage areas greater than 3 acres. Sediment trap A device for removing sediment from water flows; usually installed at outfall points. Sediment trap with gravel outlet A perimeter erosion and sedimentation control which provides filter a ponding area used to detain sediment -laden runoff long enough to allow sediment to settle out. Designed for drainage areas of one acre or less. Sedimentation The process of depositing soil particles, clays, sands, or other sediments that were picked up by flowing water. Seed and mulch The method of mechanically or manually applying grass seed mixtures and protective mulch covers to the soil surface to ultimately establish an adequate stand of grass or ground cover. Separate storm water sewer A storm water conveyance system which conveys storm system waters separately from other waste waters. Glossary - Page 7 Glossary Of Storm Water Management Terminology (Continued) Sheet flow Runoff which flows over the ground surface as a thin, even layer and is not concentrated in a channel or other conveyance. Significant material Raw materials; fuels; materials such as solvents, detergents and plastic pellets; finished materials such as metallic products; raw materials used in food processing or production; hazardous substances designated under section 101(14) CERCLA; any chemical the facility is required to report pursuant to section 313, SARA of Title III; fertilizers; pesticides; and waste products such as ashes, slag, and sludge that have a potential to be released with storm water discharges. Note that significant material refers to the type of material, not the amount. Significant spills Releases of oil or hazardous substances in excess of reportable quantities under section 311 of the Clean Water Act (see 40 CFR 110.10 and CFR 117.21) or section 102 of CERCLA (see 40 CFR 302.4). Silt fence A synthetic filter fabric stretched across and attached to posts, which intercepts and detains sediment on site; best suited for gently sloping, nearly level land. Silt trap A small, temporary ponding area, formed by constructing an earthen embankment with a gravel outlet across a drainage swale. Solid waste Any garbage, refuse or sludge, including solid, liquid, semisolid or contained gaseous material resulting from industrial, commercial, agricultural or mining operations, or community activities, excluding material in domestic sewage, discharges subject to regulation as point sources under the CWA, or any nuclear material or by- product regulated under the Atomic Energy Act of 1954. Source control A practice or structural measure to prevent pollutants from entering storm water runoff or other environmental media. Spill guard A device used to prevent spills of liquid materials from storage containers. Spill Prevention Control and Plan consisting of structures, such as diking or curbing, and Countermeasures Plan (SPCC) action plans to prevent and respond to spills of hazardous substances as defined in the Clean Water Act. SWPPPs and SPCC plans have many common features. Glossary - Page 8 Glossary Of Storm Water Management Terminology (Continued) Stabilization The process of seeding and mulching denuded areas of land to prevent soil from washing away. Storm drain Opening, usually slotted, leading to an underground pipe or an open ditch for carrying surface runoff. Storm drain inlet protector A sediment filter or an excavated impounding area around a storm drain drop inlet or curb inlet used to prevent sediment from entering storm drainage systems prior to stabilization of a disturbed area. Storm drain structure A storm drain inlet device; i.e., curb inlet or grated drop inlet, used to convey storm water through a piped system. Storm water Runoff resulting directly or indirectly from a storm event or snow melt runoff. Storm water associated with industrial activity Discharge from any conveyance which is used for collecting and carrying storm water and which is directly related to manufacturing, processing or raw materials storage areas at an industrial plant. The term does not include discharges from facilities or activities excluded from the NPDES program; and does not include discharges from unregulated areas of industrial facilities. The term includes, but is not limited to, storm water discharges from industrial plant yards; immediate access roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste material, or by- products used or created by the facility; material handling sites; refuse sites; sites used for the application or disposal of process waste waters (as defined at 40 CFR 401); sites used for the storage and maintenance of material handling equipment; sites used for residual treatment, storage, or disposal; shipping and receiving areas; manufacturing buildings; storage areas (including tank farms) for raw materials, and intermediate and finished products; and areas where industrial activity has taken place in the past and significant materials remain and are exposed to storm water. For this definition, material handling activities include the storage, loading and unloading, transportation, or conveyance of any raw material, intermediate product, finished Product, by- product or waste product. The term excludes areas located on plant lands separate from the plant's industrial activities, such as office buildings and accompanying parking lots as long as the drainage from the excluded areas is not mixed with storm water drained from the above described areas. The following categories are considered to be industrial activities or operations: (1) Hazardous waste treatment, storage, or disposal facilities, including those that are operating under interim status or a Glossary - Page 9 Glossary Of Storm Water Management Terminology (Continued) Storm water associated with permit under Subtitle C of RCRA; industrial activity (cont.) (2) Landfills, land application sites, and open dumps that have received any industrial wastes including those that are subject to regulation under Subtitle D of RCRA; (3) Transportation facilities classified as Standard Industrial Classifications 40 (Railroad Transportation) and 5171 (Warehousing) which have vehicle maintenance shops or equipment cleaning operations. Only those portions of the facility that are either involved in vehicle maintenance (including vehicle rehabilitation, mechanical repairs, painting, fueling, and lubrication), equipment cleaning operations, or which are otherwise covered under other regulated industrial activity categories are covered by this definition; (4) Construction activity including clearing, grading and excavation activities except: operations that result in the disturbance of less than five acres of total land area which are not part of a larger common plan of development or sale. Storm water discharge The discharge from any conveyance which is used for collecting and conveying (transporting) storm water. Storm water permit An NPDES permit issued by EPA or delegated state to discharge storm waters. Non - delegated states may have other required state - issued (non- NPDES) permits for discharge of storm waters. Storm Water Pollution Prevention A plan to reduce or minimize the introduction and subsequent Plan (SWPPP) discharge of pollutants in storm water discharges. Such plans are required by storm water regulations. Storm water regulations Federal and corresponding (if any) state regulations which regulate the point source discharge of storm waters. Storm water release pipe A pipe designed and installed to convey storm water runoff from a given storm recurrence interval, e.g., 25 -year storm. Storm water sewer system A conveyance system which conveys storm waters. Sump A pit or tank that catches liquid runoff for drainage or disposal. Surface impoundment A pond for treatment, storage, or disposal of liquid wastes. Surface water Any body of water that is above ground, such as a river, lake, reservoir, estuary, pond, creek or stream. Glossary - Page 10 Glossary Of Storm Water Management Terminology (Continued) Swale An elongated depression in the land surface that is at least seasonally wet, is commonly vegetated, and is normally without flowing water except during storm event periods. Swales direct storm water flows into primary drainage channels and allow some of the storm water to infiltrate into the ground surface; vegetation may also promote biological changes in flowing water containments. Tarp A sheet of waterproof canvas or other material used to cover and protect materials, equipment, or vehicles. Temporary construction entrance A rock pad covering the width of the construction entrance, used to remove mud from the tires of heavy equipment vehicles. Often a wash rack is used at the entrance also. Temporary slope drain A flexible conduit extending from the top to the bottom of a steep slope which is used to convey storm water runoff above the slope to the bottom of the slope. Total dissolved solids The concentration of minerals in water. Total suspended solids (TSS) A measure of the suspended solids in wastewater, effluent, storm water or similar waters; determined by using test for total suspended non - filterable solids. Toxic pollutants Any pollutant listed as toxic under Section 501(a)(1) or, in the case of "sludge use or disposal practices," any pollutant identified in regulations implementing Section 405(d) of the CWA; toxics are injurious to human health or animals. Treatment The act of applying a procedure or chemicals to a substance to remove undesirable pollutants. Tributary A river or stream that flows into a larger river or stream. Underground storage tank (UST) Resource Conservation and Recovery Act (RCRA) regulated tank and connected piping with 10 or more percent of its volume underground; used to store petroleum products or CERCLA- regulated hazardous chemicals. Waste Unwanted materials left over from a manufacturing, industrial or other process or activity. Glossary - Page 11 Glossary Of Storm Water Management Terminology (Continued) Waste pile Any non - containerized accumulation of a solid, nonflowing waste that is used for treatment or storage. Wastewater Process water contaminated to such an extent that it cannot be reused without some repurification. WWTP Wastewater treatment plant. Waterway A channel for the passage or flow of water. Wetlands An area that is regularly saturated by surface or ground water and subsequently is characterized by a prevalence of vegetation that is adapted for life in saturated soil conditions. Examples include: swamps, bogs, alluvial fans, marshes, and estuaries. Glossary - Page 12 Reference List The following may be helpful reference material to area municipalities conducting storm water quality programs for construction activities: ♦ Storm Water Quality Best Management Practices Manual for Construction Activities for North Central Texas, North Central Texas Council of Governments, Department of Environmental Resources, PO Box 5888, Arlington, Texas 76005 -5888, (817) 640 -3300 ♦ SWP3 Expert System for Construction Activities, Software and User's Manual, City of Dallas, Texas, Available from North Central Texas Council of Governments, Department of Environmental Resources, PO Box 5888, Arlington, Texas 76005- 5888, (817) 640 -3300 ♦ Keeping Soil on Construction Sites: Best Management Practices; Available from Ohio Department of Natural Resources, Division of Soil and Water Conservation, Fountain Square, E -2, Columbus, OH 43224 ♦ Training Program for Site Inspections, Available from Fairfax Virginia Department of Environmental Management, (703) 324 -1734 ♦ Virginia Erosion and Sediment Control Handbook, Third Edition, 1992, Virginia Department of Conservation and Recreation, Division of Soil and Water Conservation, 203 Governor Street, Suite 206, Richmond, VA 23219 -2094, (804) 786 -2064 ♦ New York Guidelines for Urban Erosion and Sediment Control, Third Printing, 1991, Available from Empire State Chapter - SWCS, PO Box 712, Syracuse, NY 13261- 7172 Appendix 4 Reference List The following may be helpful reference material to area municipalities conducting storm water quality programs for construction activities: ♦ Storm Water Quality Best Management Practices Manual for Construction Activities for North Central Texas, North Central Texas Council of Governments, Department of Environmental Resources, PO Box 5888, Arlington, Texas 76005 -5888, (817) 640 -3300 ♦ Keeping Soil on Construction Sites: Best Management Practices; Available from Ohio Department of Natural Resources, Division of Soil and Water Conservation, Fountain Square, E -2, Columbus, OH 43224 ♦ Training Program for Site Inspections, Available from Fairfax Virginia Department of Environmental Management, (703) 324 -1734 ♦ Virginia Erosion and Sediment Control Handbook, Third Edition, 1992, Virginia Department of Conservation and Recreation, Division of Soil and Water Conservation, 203 Governor Street, Suite 206, Richmond, VA 23219 -2094, (804) 786 -2064 ♦ New York Guidelines for Urban Erosion and Sediment Control, Third Printing, 1991, Available from Empire State Chapter - SWCS, PO Box 712, Syracuse, NY 13261- 7172