Understanding Stormwater Pollution Prevention Plans (SWPPPs) (SWPPPS)

Transcription

1 Understanding Stormwater Pollution Prevention Plans (SWPPPs) (SWPPPS)

2 Definitions SWPPP: Storm Water Pollution Prevention Plan BMP: Best Management Practice(s) to control pollution IDNR: Iowa Department of Natural Resources EPA: Environmental Protection Agency GP #2: General Permit Number 2

3 What You Need to Know About SWPPPs The story for the construction project Identifies all potential sources of pollution Identified all co-permittees Living Document Types and locations of best management practices Phases of construction Identifies sensitive areas to protect

4 Storm Water Permits and SWPPPs The U.S. Environmental Protection Agency (EPA) has determined that construction activities which cause a land disturbance of one or more acres require a Nonpoint Discharge Elimination System (NPDES) permit. Iowa's NPDES General Permit No. 2 covers storm water discharges from construction activities (land disturbances). An operator of a construction site must file a Notice of Intent (NOI) with the Iowa Department of Natural Resources (IDNR) for coverage under Iowa s General Permit #2 before beginning construction activities. Iowa's General Permit No. 2 requires that a storm water pollution prevention plan (SWPPP) for the construction activity be developed before the Notice of Intent is submitted to the IDNR.

5 Outstanding National Or State Resource Water Any discharge from a facility or construction site that may temporarily degrade an Outstanding National Resource Water or Outstanding State Resource Water is required to be permitted by an individual NPDES permit. For more information about storm water permits, contact the IDNR Storm Water Program Coordinator at

6 What is a Stormwater Pollution Prevention Plan? (SWPPP) A SWPPP is a site specific, written, living document that: Identifies potential sources of stormwater pollution at a construction site, Describes practices to reduce pollutants in stormwater discharges, often achieved by reducing the volume of stormwater runoff, and Identifies procedures the operator will implement to comply with the requirements of a general construction permit.

7 Why do I need to understand SWPPPs? A construction site operator (your employer) must be in compliance with storm water permit requirements. A SWPPP is part of the permit contract documents. All other contractors working within the site area must sign the SWPPP Certification as a co-permittee* (EPA rules). It s important that construction site SWPPPs address specific site conditions, are fully implemented and kept updated to reflect any changes at a construction site. If storm water pollution control measures are improperly installed or not completed in a timely manner, a noncompliance notice can be issued.

8 Impacts of Noncompliance Financial: Failure of a site operator to implement an effective SWPPP could result in significant fines from the EPA or IDNR. Environmental: erosion causes the loss of valuable topsoil, the deposition of sediment in streams and lakes, increases the potential for flooding, damages plant and aquatic life, and can cause structural damage to buildings and roads. The No. 1 pollutant by volume in Iowa is sediment! A major source of sediment comes from unprotected construction sites under development.

9 Communication and Coordination Communication and coordination between the site operator and contractor is essential if the project is going to be in compliance with storm water permit requirements and the SWPPP! The timing of erosion and sediment control installation goes hand in hand with the site operator s staging and work plan.

10 Why are we doing this? To protect and improve the quality of Iowa streams and lakes

11 Elements of a SWPPP Site description BMPs - sequencing, temporary and permanent practices Erosion and sediment controls Structural practices Soil Management Plan Stormwater management Waste Disposal, Dust Management Compaction reduction and topsoil replacement What to inspect and when, reports and any changes made to the SWPPP Every 7 calendar day inspections by identified, qualified personnel

12 The Secret of a Good SWPPP: Planning Based on existing site conditions Identifies the nature of construction Describes schedule and season of construction activities Nilles Associates Identifies contractors and subcontractors

13 SWPPP Components Plans must be a combination of: A narrative describing the timing for installation of BMPs... Nilles Associates

14 SWPPP Components Plans must be a combination of: A narrative Plan sheets... Nilles Associates

15 SWPPP Components Plans must be a combination of: A narrative Plan sheets And if necessary, plan detail sheets

16 Summary Guidance Phase 1: Site Evaluation and Design Development Phase 2: Assessment Phase 3: Control Selection and Plan Design Phase 4: Plan Certification and Submitting an NOI Phase 5: Construction and Implementation Phase 6: Final Stabilization and Notice of Discontinuation

17 Contact List Nilles Associates

18 Outline of SWPPP Document Nilles Associates

19 (1) Site Evaluation and Design Development - Part A Existing soils Existing runoff quality Location of surface waters on the construction site Lakes, rivers, streams and wetlands Name of receiving waters If MS-4 system, where does it go? Does the site drain to an impaired waterway? Legal description Nilles Associates

20 Site Evaluation and Design Development - Part B Site Plan Evaluation and Design Site Location, topography, proposed improvements, location of streams and proposed controls. Disturbs the smallest area possible. Avoids disturbing sensitive areas: steep slopes, erosive soils and stream channels. Identifies areas to be preserved or left as open spaces. Nilles Associates

21 Protect Sensitive Areas: Wetlands, Trees Nilles Associates

22 Snow Fence to Protect Vegetation and Soil

23 Site Evaluation and Design Development - Part C and D Description of Construction Activity What is the activity? What type of equipment is going to be used? What types of chemicals are going to be stored on site? Preparation of Pollution Prevention Site Map Slopes Proposed Grades Disturbed Areas Drainage Patterns or Discharge Points

24 Combine Practices to Reduce Erosion Nilles Associates

25 (2) Assessment Site Area is Measured Drainage Areas are Determined Look at both on- and off-site areas Runoff Coefficient is Calculated Or Curve Number/Other Measure how much runoff site will generate Nilles Associates

26 Why are the site evaluation and assessments the first steps? All sites are different, SWPPPs should be unique for each site Boiler plate for type and location of practices will not work!

27 (3) Control Selection and Plan Design Local Requirements are Reviewed and Incorporated Erosion and Sediment Controls are Selected Stabilization (erosion control) Structural practices (sediment) Dust Control Topsoil-how removed, stored, replaced Other Controls Selected Rubble, trash, sanitary waste, tracking, etc. Stormwater Management Controls Ponds, wetlands, sediment basins, etc. Nilles Associates

28 Control Selection and Plan Design Controls are Located on the Site Map Inspection and Maintenance Plan is Prepared Description of Controls is Prepared Sequence of Activities (Project Specific) is Prepared Nilles Associates

29 Sequence Of Activities Install down slope or perimeter controls before starting Do not disturb areas until necessary Cover and stabilize areas as soon as possible Time activities to limit impact from seasonal changes or weather events Delay final construction of infiltration measures until end of project when upstream areas are stabilized Topsoil requirements Do not remove temporary controls until all upstream areas are stabilized

30 Using The Right Tools Erosion Control Sediment Control Velocity Control Pollution Prevention Storm Water Management Controls Post Construction

31 Erosion Controls: Stabilization Practices Maintain Existing Vegetation Vegetative Filter Strips Compost blankets Dust Control Grass Channel Mulching Temporary and Permanent Seeding Sodding Surface Roughening-Grading Strategies Turf Reinforcement Mats Rolled Erosion Control Products Compost Blanket on a storm water detention basin at North High School in Davenport.

32 Structural Practices Structural practices (Sediment Control) - description of practices to divert, store flows or limit runoff, list of practices For common drainage location serving 10 disturbed acres, a temporary or permanent sediment basin providing 3,600 cubic feet of storage per acre drained shall be provided, alternatives given where not attainable

33 Structural Controls: Sediment Control Practices Filter berm Filter sock Wattle Flocculants Floatation silt curtain Inlet protection devices Sediment control basins and traps Silt fence, Georidge and similar products Stabilize construction exits

34 Structural Controls: Velocity Control Practices Check Dams Diversion Structures Level Spreader Rock Chutes and Flumes Rock Outlet Protection Flow Transition Mats Temporary Slope Drains

35 Pollution Prevention Practices: Concrete washouts Chemical storage and handling Offsite tracking minimized Sanitary waste Dust control

36 Storm Water Management Wet/Dry Ponds Constructed Wetlands Bioretention Cells Bioswales Infiltration Trenches Native Landscaping Permeable Paving Alternatives Rain Gardens Soil Quality Restoration Mechanical Systems

37 Sample Site Map Diversion to cut off overland flow Rock chute Critical area seeding (steep slope >3:1) Silt fence Permanent seeding Building setback line Property line Stabilized construction entrance Culvert outlet protection Check dams Proposed pond as sediment basin (outlets to ditch)

38 (4) Plan Certification and Submittal of Notice of Intent Who needs to Certify? Operator (owner or prime contractor) signs both NOI and plan certification All other contractors working within the site area must sign on as co-permittee* Language is standard and is defined by State law Is part of the SWPPP needs to be kept together Submit the signed NOI. All previous steps have been completed Need copies of two public notices (signed proof of publication) Until IDNR authorizes coverage, construction activities may not be started

39 SWPPP Contents: SWPPP Certification I certify under penalty of law that I understand the terms and conditions of the general National Pollutant Discharge Elimination System (NPDES) permit that authorizes the storm water discharges associated with industrial activity from the construction site as part of this certification. Further, by my signature, I understand that I am becoming a co-permittee, along with the owner(s) and other contractors and subcontractors signing such certifications, to the Iowa Department of Natural Resources NPDES General Permit No. 2 for "Storm Water Discharge Associated with Industrial Activity for Construction Activities" at the identified site. As a co-permittee, I understand that I, and my company, are legally required under the Clean Water Act and the Code of Iowa, to ensure compliance with the terms and conditions of the storm water pollution prevention plan developed under this NPDES permit and the terms of this NPDES permit.

40 (5) Construction and Implementation Controls are Implemented Follow Sequence of Events (developed in Phase 3) Add or edit controls or sequence to reflect changing site conditions document changes: SWPPP should be a living document and up to date at all times Stabilize within 14 days of last construction activity in a given area, or where construction will not occur within a period of 21 calendar days Controls are Inspected and Maintained Site inspection at disturbed areas that have not been stabilized with a perennial, vegetative cover of sufficient density to preclude erosion once every 7 days and after any storm event with at least.05 inches of rainfall Keep controls in good working order Verify that identified maintenance needs have been addressed

41 Construction and Implementation Records of Construction Activities are Maintained Dates when grading occurs in particular areas Dates when activity ceases (either temporarily or permanent) Dates of temporary or permanent stabilization (remember the 14/21 day rules) Plan Updated and Kept Current Plan Map should always reflect current and past site conditions Add new contractor certifications and any changes in ownership (Co-permittees*) *New Draft Rules Nilles Associates

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43 Construction and Implementation Any hazardous condition should be reported and the plan updated Notify the IDNR and local sheriff ASAP after a spill (no longer than 6 hours) Update the plan within 14 days to note the conditions surrounding the spill, and prevention steps taken to prevent it from happening again The SWPPP location should be known and accessible to everyone working on the site Must be kept on site Keep all records for 3 years after final site stabilization Access need to be available for review upon request Nilles Associates

44 (6) Final Stabilization and Notice of Discontinuation Final Stabilization All land disturbing activities are completed Uniform perennial vegetative cover established or equivalent measures (revetment, geotextiles, etc.) are installed Notice of Discontinuation Within 30 days of final stabilization All temporary controls should have been removed Submit form to IDNR ends coverage under General Permit No. 2 Nilles Associates

45 Copy of NOI Permit Authorization Schematic SWPPP Map Recorded Changes to Plan Document reasons for changes Copies of Inspection Reports Certification Statement by Inspection Personnel Certification by Contractor/Owner Copies of Records of Change in Ownership or Responsibility Notice of Discontinuation Copy of the NPDES General Permit No. 2 Nilles Associates

46 Before Notice of Discontinuation Final site stabilization with permanent perennial cover!

47 Available Resources General Permit No. 2 Summary Guidance IDNR Forms and Manuals Statewide Urban Design and Specifications Iowa Stormwater Management Manual Iowa Stormwater Partnership

48 Class Project: SWPPP Interpretation

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