MS4 Stormwater Permit
Program and Great Bay
Brief Overview – EPA’s Stormwater
Management Program
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Clean Water Act – NPDES - 1987 Stormwater amendments
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Two Phase approach to stormwater permitting
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Industrial activities
Construction
MS4s
Phase II stormwater management program promulgated in 1999
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Construction > 1 acre but less than 5
Small MS4s (population served < 100,000)
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2003 - General Permit for Small MS4s in MA and NH issued
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2008 – MS4-2003 expired, Draft Permit for NH MS4s public
notice
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Final Permit expected early 2012
What is an MS4?
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A municipal separate storm sewer system is:
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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
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Includes
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roads with drainage systems, municipal streets, catch basins,
curbs, gutters, ditches, man-made channels, or storm drains
Does not include
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Combined sewers
Parts of publicly owned treatment works
Private systems
Summary of NH MS4 permit issuance
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Phase II regulated MS4s are those located in an
urbanized area as defined by the latest Census
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NH Phase II regulated MS4s: 38 Traditional, 4 Nontraditional, 7 Waivers
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2003 Small MS4 GP covered regulated small MS4s in
MA and NH, expired 2008 (administratively continued)
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Draft NH Small MS4 General Permit issued for public
notice 2008. MA versions issued in 2010 and 2011
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Final Permit issuance expected early 2012 with spring
2012 effective date
Regulated MS4s in Great Bay Watershed
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Phase II regulated MS4s are
those located in an “urbanized
area” (Census definition)
 Great Bay watershed MS4s:
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Brentwood*
Chester*
Danville
Dover
Durham
East Kingston*
Exeter
Greenland
Hampstead
Hampton Falls*
Kingston
Lee*
Madbury*
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Milton
Newington*
North Hampton
Portsmouth
Rochester
Rollinsford
Sandown
Somersworth
NH DOT
Strafford County
Commissioners
UNH
* waiver under MS4-2003
MS4 Permit Structure
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Technology standard: reduce discharge of pollutants
to the “Maximum Extent Practicable”
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Implemented through requirements for six “minimum
control measures”
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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
MS4 Implementation
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Stormwater Management Program
(SWMP)
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“Best management practices” (BMPs) to
implement six minimum controls and water
quality based requirements
Annual assessment and reporting
 Reports available on EPA website
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http://www.epa.gov/region1/npdes/stormwater/2003-permit-archives.html
Public Education and Outreach
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2003- General program
requirement
 Draft reissuance
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Specific audiences for
education
Specific education topics
Specific number of
educational messages
Evaluation of the
effectiveness of educational
messages
Illicit Discharge Detection and
Elimination (IDDE) Program
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2003 permit: ordinance/regulatory mechanism,
outfall map, establish procedures
Draft reissuance:
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Complete system map
More specific requirements for:
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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
Construction
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2003 Permit –Ordinance/
regulatory mechanism
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Draft reissuance
Site plan review process
 Site inspections and
enforcement
 Education
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Post-Construction
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2003 Permit – Ordinance/
regulatory mechanism covering
new development and
redevelopment
Draft reissuance
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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
Good House Keeping
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2003 Permit - Develop a written
program to prevent/reduce
stormwater pollution from municipal
activities and facilities
 Draft reissuance
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Standard operating procedures –
parks, buildings, vehicles, and roads
Specific infrastructure maintenance
requirements
Stormwater Pollution Prevention
Plans (SWPPP) for maintenance
garages and waste handling facilities
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Facility inspections
Employee training
Water Quality Requirements
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TMDLs
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Specific applicable BMPs identified
Discharges to Impaired Waters
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BMPs addressing pollutant of concern to be
included in SWMP
Nitrogen Reduction Potential through
MS4 Requirements
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Target minimum Controls relevant to N reduction
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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
Questions?
Susan Murphy
U.S. Environmental Protection Agency
Murphy.Susan@epa.gov
(617) 918-1534