Stormwater

DEP’s stormwater laws and regulations work toward protecting and restoring surface water and groundwater impacted by stormwater flows. Stormwater runoff from developed areas carries pollutants, and affects the rates and volumes of flows in natural waterbodies in ways that can cause damage. Everyone has a role in reducing impacts from stormwater runoff, from the large developer constructing a new parking lot, to the homeowner using good erosion control methods and handling chemicals carefully around the house.

DEP regulates a variety of stormwater programs under three core laws:

  • Site Location of Development Law (Site Law). This law relates to larger commercial and residential developments in Maine, in general, projects that create more than 3 acres of new impervious area (like buildings and parking lots), or occupy more than 20 acres of land (like golf courses and ski areas). The Site Law reviews several environmental standards, including potential stormwater impacts from proposed developments.
  • Stormwater Management Law. Maine’s Stormwater Management Law lists stormwater standards for projects that propose more than one acre of disturbed area. Disturbed area generally includes areas that are stripped, graded, excavated, or filled during construction. The Stormwater Management Law includes standards for both the quantity of stormwater runoff, as well as the quality of that runoff.
  • Waste Discharge Law. A waste discharge license is required for the discharge of pollutants to Maine’s environment. There are a number of general permits that the DEP administers, including the Multi-Sector General Permit, the Municipal Separate Storm Sewer Systems (MS4) General Permit, and the Maine Construction General Permit, that cover a wide variety of activities.

Additional information about the laws, rules, application forms and other materials is available at the three links above.

Contacts

For general questions related to the Site Law or Stormwater Management Law, please contact us through our Bureau of Land Resources ‘on-call’ system. Depending on the location of the project, contact one of the DEP’s regional offices, and ask to speak with the "on-call" person for the Site Law program in the Bureau of Land Resources. For general questions related to the Waste Discharge Law, please contact us through our Bureau of Water Quality ‘on-call’ system. Depending on the location of the project, contact one of the DEP’s regional offices, and ask to speak with the "on-call" person for the Waste Discharge License program in the Bureau of Water Quality.

  • Augusta: 800-452-1942
  • Bangor: 888-769-1137
  • Portland: 888-769-1036
  • Presque Isle: 888-769-1053