Creating a Storm Water Pollution Prevention Plan

1. Creating a Storm Water Pollution Prevention Plan For Construction Activities

2. Creating a Storm Water Pollution Prevention Plan A requirement of the construction storm water permit is to develop a storm water pollution prevention plan (SWPPP) before construction activities begin. The SWPPP should be complete before submitting the Notice of Intent (NOI). The following slide show will step through each item that is to be addressed in the SWPPP. By following this guide, you will be able to develop a SWPPP that fulfills the requirements of the Arkansas Department of Environmental Quality.

3. SWPPP Organization Guideline • Site Evaluation and Design Development: • Collect site information • Develop Site Plan • Prepare pollution prevention site map

4. SWPPP Organization Guideline • Assessment: • Measure the site area • Determine the drainage areas • Calculate the runoff coefficient

5. SWPPP Organization Guideline • Control Selection / Plan Design: • Select erosion and sediment controls • Select other controls • Select storm water management controls • Indicate the location of controls on the site map • Site map requirements

6. SWPPP Organization Guideline • Control Selection / Plan Design Continued: • Prepare an inspection and maintenance plan • Prepare sequence of major activities • Incorporate State or local Requirements

7. SWPPP Organization Guideline • Certification / Notification: • Certify the plan • Submit Notice of Intent • Plan location

8. SWPPP Organization Guideline • Construction / Implementation: • Implement controls • Inspect and maintain controls • Update / change the plan • Report releases of reportable quantities

9. SWPPP Organization Guideline • Final Stabilization / Termination • Final stabilization • Notice of Termination

10. SWPPP The following is a step-by-step description of each item in the organizational list that was previously supplied. By addressing each item in the list, an acceptable SWPPP can be developed that meets ADEQs basic criteria.

11. Site Evaluation and Design • Collect site information • Existing conditions site map • Soils information • Runoff water quality • Name of receiving stream / water • Rainfall data

12. Site Evaluation and Design • Develop Site Plan • Disturb the smallest vegetated area possible • Keep the amount of cut and fill to a minimum • Limit impacts to sensitive areas such as: • Steep and / or unstable slopes • Surface waters, including wetlands • Areas with soil is likely to erode • Existing drainage channels

13. Site Evaluation and Design • Prepare Pollution Prevention Site Map • Approximate slopes after grading • Indicate areas of soil disturbance • Indicate drainage patterns

14. Assessment • Measure site area • Indicate the total site area and the area which will be disturbed

15. Assessment • Determine the Drainage Area • Measure the size of each drainage basins for each point where concentrated flow will leave the site • Use the calculated concentrated flow to determine the appropriate sediment control measures

16. Assessment • Calculate the Runoff Coefficient • Develop an estimate of the development’s impact on runoff after construction is complete. This can be done by estimating a runoff coefficient for post-construction conditions Q = (C) * (I) * (A) where Q = the rate of runoff from an area C = partial amount of the total rainfall that will become runoff I = rainfall intensity, and A = the area of the drainage basin

17. Assessment Continued • Calculate the Runoff Coefficient Continued • Calculating a “weighted” runoff coefficient: where A = acres and C = coefficient

18. Assessment Continued

19. Control Selection / Plan Development • Select erosion and sediment controls • Stabilization measures for disturbed areas • Structural controls to divert runoff and remove sediments • Erosion and sediment controls can include temporary or permanent measures

20. Control Selection / Plan Development • Select other controls • Proper waste disposal • Control of offsite vehicle tracking • Compliance with applicable State or local waste disposal • Sanitary sewer or septic system regulations • Control of allowable non-storm water discharges

21. Control Selection / Plan Development • Select storm water management controls • Storm water detention structures (including wet ponds) • Storm water retention structures • Open vegetated swales • Natural depressions • Infiltration measures

22. Control Selection / Plan Development • Indicate location of controls on the site map • Areas of permanent seeding • Areas of sod stabilization • Silt fence • Straw bale barrier • Earth dikes • Brush barriers • Drainage swales • Sediment traps

23. Control Selection / Plan Development • Indicate location of controls on the site map • Pipe slope drains • Level spreaders • Storm drain inlet protection • Reinforced soil retaining systems • Gabions • Temporary or permanent sediment basins • Stabilized construction entrances

24. Control Selection / Plan Development • Site map requirements • Drainage patterns • Approximate slopes after grading • Area of soil disturbance • Location of major structural and nonstructural controls • Areas where stabilization practices are expected to occur • Location of surface waters

25. Control Selection / Plan Development • Prepare an inspection and maintenance plan • Qualified personnel shall inspect disturbed areas of the construction site at least once every seven calendar days and within 24 hours of the end of a storm that is 0.5 inches or greater • A description of procedures to maintain in good condition and effective operating condition • Vegetation • Erosion and sediment control measures • Other protective measures identified in the site plan

26. Control Selection / Plan Development • Prepare sequence of major activities • The sequence of major activities should include a timeline for: • Construction of control measures • Earth disturbing construction activities • Maintenance activities for control measures in the order in which they will occur • Down slope and side slope perimeter controls should be installed before the land disturbing activity occurs • Do not disturb an area until it is necessary for construction to proceed • Cover or stabilize as soon as possible

27. Control Selection / Plan Development • Prepare sequence of major activities continued • The sequence of major activities should include a timeline for: • Time activities to limit impact form seasonal climate changes or weather events • Construction of infiltration measures should be delayed to the end of the project when upstream drainage areas have been stabilized

28. Control Selection / Plan Development • Incorporate state or local requirements • Permittees shall incorporate all applicable requirements specified in State or local sediment and erosion control plans or permits, or storm water management plans or permits. This should include requirements such as • City ordinances • City grading permit requirements

29. Certification and Notification • Certify the Plan • Your NPDES storm water permit requires that authorized representative(s) of the operator(s) sign and certify the plan. The authorized representative(s) should be individuals at or near the top of the management chain, such as: • The president • Vice-president • General partner, who has been delegated the authority to sign and certify this type of document

30. Certification and Notification • Notice of Intent • You are required to submit a Notice of Intent (NOI) prior to commencement of construction • The NOI cannot be submitted until the SWPPP has been prepared

31. Certification and Notification • Plan location • SWPPPs for construction activities shall be maintained onsite of the activity unless the Director, or authorized representative, the operator of a large or medium MS4, or a State or local sediment and control agency requests that the plan be submitted. • Permittees should keep a copy of the plan at the construction site until the site is finally stabilized • Permittees are required to keep the plan, all reports and data for at least three years after the project is complete

32. Construction / Implementation • Implement controls • The controls should be constructed or applied in accordance with State or local standard specifications • If there are no State or local specifications for control measures then the controls should be constructed in accordance with good engineering practices • Improperly installed controls can have little or no effect and may actually increase the pollution of storm water

33. Construction / Implementation • Inspect and maintain controls • Inspection should be performed at the frequency specified in the SWPPP and / or the permit • The inspector should note any damage or deficiencies in the control measures in an inspection report • The inspector should correct damage or deficiencies as soon as practicable after the inspection • The operator should keep records of the construction activity on the site, such as: • Dates when major grading activities occur in a particular area • Dates when construction activities cease in an area • Dates when an area is stabilized

34. Construction / Implementation • Update / change plans • SWPPPs are developed based on site-specific features and functions. Where there are changes in design, construction, operation, or maintenance, and that change will have a significant effect on the potential for discharging pollutants in storm water at a site, the SWPPP should be modified by the permittee to reflect the changes and new conditions • The permittee is required to update the plan as necessary to reflect any changes onsite which may affect the potential for discharges of pollutants from the site

35. Construction / Implementation • Releases of reportable quantities • If the construction site has a release of a hazardous substance or of oil in an amount which exceeds a reportable quantity (RQ) as defined at 40 CFR Part 110, 40 CFR Part 117, or 40 CFR Part 302, then the permittee shall do several things: • The person in charge of the site at the time of the spill shall call the National Response Center to report the spill – 800-424-8802 • Within 14 days after the release is detected, modify the site SWPPP • Within 14 days of the release, submit a written description of the release to ADEQ

36. Final Stabilization / Termination • Final stabilization • A site can be considered finally stabilized when all soil disturbing activities at the site have been completed and a uniform perennial vegetative cover with a density of 70 percent for the unpaved areas and areas not covered by permanent structures has been established or equivalent permanent stabilization measures have been employed

37. Final Stabilization / Termination • Notice of Termination • The Notice of Termination (NOT) is the final task required to comply with the requirements of an NPDES storm water permit for a construction activity. The NOT form is sent to the permittee with the confirmation letter. Additional NOTs can be obtained by contacting the storm water staff at ADEQ