MS4 Stormwater Permit Program and Great Bay

1. MS4 Stormwater Permit Program and Great Bay

2. Brief Overview – EPA’s Stormwater Management Program • Clean Water Act – NPDES - 1987 Stormwater amendments • Two Phase approach to stormwater permitting • Industrial activities • Construction • MS4s • Phase II stormwater management program promulgated in 1999 • Construction > 1 acre but less than 5 • Small MS4s (population served < 100,000) • 2003 - General Permit for Small MS4s in MA and NH issued • 2008 – MS4-2003 expired, Draft Permit for NH MS4s public notice • Final Permit expected early 2012

3. What is an MS4? • A municipal separate storm sewer system is: • A conveyance or system of conveyances owned by a state, city, town, or other public entity that discharges to waters of the U.S and is designed or used for collecting or conveying stormwater • Includes • roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains • Does not include • Combined sewers • Parts of publicly owned treatment works • Private systems

4. Summary of NH MS4 permit issuance • Phase II regulated MS4s are those located in an urbanized area as defined by the latest Census • NH Phase II regulated MS4s: 38 Traditional, 4 Non-traditional, 7 Waivers • 2003 Small MS4 GP covered regulated small MS4s in MA and NH, expired 2008 (administratively continued) • Draft NH Small MS4 General Permit issued for public notice 2008. MA versions issued in 2010 and 2011 • Final Permit issuance expected early 2012 with spring 2012 effective date

5. Regulated MS4s in Great Bay Watershed • Phase II regulated MS4s are those located in an “urbanized area” (Census definition) • Great Bay watershed MS4s: • Brentwood* • Chester* • Danville • Dover • Durham • East Kingston* • Exeter • Greenland • Hampstead • Hampton Falls* • Kingston • Lee* • Madbury* • Milton • Newington* • North Hampton • Portsmouth • Rochester • Rollinsford • Sandown • Somersworth • NH DOT • Strafford County Commissioners • UNH * waiver under MS4-2003

6. MS4 Permit Structure • Technology standard: reduce discharge of pollutants to the “Maximum Extent Practicable” • Implemented through requirements for six “minimum control measures” • Public education and outreach • Public participation • Illicit discharge detection and elimination • Construction stormwater management • Post-construction (development/redevelopment) • Municipal good housekeeping/pollution prevention • Water Quality based requirements & TMDLs

7. MS4 Implementation • Stormwater Management Program (SWMP) • “Best management practices” (BMPs) to implement six minimum controls and water quality based requirements • Annual assessment and reporting • Reports available on EPA website • http://www.epa.gov/region1/npdes/stormwater/2003-permit-archives.html

8. Public Education and Outreach • 2003- General program requirement • Draft reissuance • Specific audiences for education • Specific education topics • Specific number of educational messages • Evaluation of the effectiveness of educational messages

9. Illicit Discharge Detection and Elimination (IDDE) Program • 2003 permit: ordinance/regulatory mechanism, outfall map, establish procedures • Draft reissuance: • Complete system map • More specific requirements for: • Assessment of MS4 for illicit discharge potential • Systematic procedure for locating and removing illicit connections, includes outfall inventory & monitoring • Prevent illicit discharges and SSOs • Track program success • Annual employee training • Sampling/monitoring

10. Construction • 2003 Permit –Ordinance/ regulatory mechanism • Draft reissuance • Site plan review process • Site inspections and enforcement • Education

11. Post-Construction • 2003 Permit – Ordinance/ regulatory mechanism covering new development and redevelopment • Draft reissuance • Regulatory program requirements for plan review, design criteria (1” capture), BMP maintenance requirements • Assessment of street design to support low impact development • Assessment of regulations to allow green infrastructure practices • Tracking impervious areas (IA) and implement efforts to reduce IA www.cwp.org

12. Good House Keeping • 2003 Permit - Develop a written program to prevent/reduce stormwater pollution from municipal activities and facilities • Draft reissuance • Standard operating procedures – parks, buildings, vehicles, and roads • Specific infrastructure maintenance requirements • Stormwater Pollution Prevention Plans (SWPPP) for maintenance garages and waste handling facilities • Facility inspections • Employee training

13. Water Quality Requirements • TMDLs • Specific applicable BMPs identified • Discharges to Impaired Waters • BMPs addressing pollutant of concern to be included in SWMP

14. Nitrogen Reduction Potential through MS4 Requirements • Target minimum Controls relevant to N reduction • Education – fertilizer use, septic system maintenance • IDDE – illicit discharges are potentially large source of nitrogen loads • Post-Construction – require stormwater management effective in control of N, LID • Good House Keeping – fertilizer use, infrastructure maintenance • Water Quality based requirements – Final permit to include specific N requirements for Great Bay watershed

15. Questions? Susan Murphy U.S. Environmental Protection Agency Murphy.Susan@epa.gov (617) 918-1534