NHARPC CORNER: What is the 2017 NH Small MS4 General Permit and How Can Your RPC Help?

Various contributors from the New Hampshire Association of Regional Planning Commissions

Q: What is the NH Small MS4 General Permit?

A:   Coming out of the Clean Water Act, the federal EPA MS4 Stormwater Permit for New Hampshire municipalities is formally known as the General Permit for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems (MS4). This federal permit is intended to address and reduce stormwater pollution, at a local level, originating from municipally-owned facilities and land, including local roads.

Q: Which municipalities does the MS4 General Permit apply to?

A:   The areas that are affected are based upon the 2010 census data. Of the 60 NH municipalities that include designated areas, 44 are regulated under the permit and 16 have been granted a waiver from permit requirements.

Q:  Why should you be concerned with stormwater?

A:   Harmful pollutants such as oil, fertilizer, pesticides, sediment, and chemicals are deposited on soil and impervious surfaces.  When stormwater (rain, snow and ice melt) flows over these surfaces it carries the pollutants with it and enters into storm drains and discharges into our lakes, streams, rivers, ponds, and oceans.  This pollution significantly affects the environment, eco-systems and the water quality.

Because development and urbanization increase the amount of impervious surfaces, there is increased danger of flooding if stormwater is not correctly managed.  Roads, parking lots, roofs etc. are all surfaces which can contain pollutants and stormwater must travel over these to drain. Flooding significantly damages our natural and built environment.

Q:  What are the benefits of stormwater management?

A:   Managing stormwater in your community improves the water and environmental and reduces the severity and impact of flooding. These factors increase livability, safety, the environment, and decrease damage to infrastructure and property.

Q:  What do municipalities have to do to be in compliance with this permit?

A:   The permit requires municipalities to develop a stormwater management program that controls pollutants from all of the MS4 discharge points to the “Maximum Extent Practicable.” This program must include the six minimum control measures listed below as well as an annual report to EPA summarizing progress toward achieving specific measurable goals:

  • Public education and outreach on stormwater impacts.
  • Public involvement/participation during program development.
  • Illicit discharge detection and elimination.
  • Construction site storm water runoff control.
  • Post-construction storm water management in new development and redevelopment.
  • Pollution prevention/good housekeeping for municipal operations.

Q:  How can regional planning commissions help municipalities?

A:   There are many areas in which your regional planning commission can offer services, which include:

  • Preparation of the Notice of Intent
  • MS4 permit research and advising; dedicated shared professional stormwater staff; assistance and guidance with applications for pertinent grants
  • Coordination and sharing of resources
  • Host workshops and trainings; Outreach and education
  • Municipal permit compliance assessment utilizing a “road map” to guide yearly compliance activities and collection of data and information for annual reports
  • Regulatory audit of zoning and regulations; Amendments to regulations and zoning ordinances
  • GIS services and mapping of MS4 systems, stormwater infrastructure data, and impervious areas
  • Hot spot pollutant load analysis and assistance with use of the “Pollutant Tracking and Accounting Program” (in development by NHDES)
  • Preparation of water systems maps depicting impaired waters, MS4 systems, sub-watersheds and drainage pathways and outfalls

For More Information

Contact your Regional Planning Commission for more information and to inquire about local assistance:

Additional information is available online from NH DES and EPA Region 1: