The U.S. Environmental Protection Agency (EPA) oversees the National Pollutant Discharge Elimination System (NPDES) Phase II permitting program. The program is intended to improve water quality by reducing the discharge of pollutants from stormwater runoff into local storm drains, rivers, ponds, streams and other receiving waterbodies.

The Town’s drainage system operates as a Municipal Separate Storm Sewer System (MS4) under this permit program. The federal regulations governing this permit are known as the Storm Water Phase II MS4 Regulations, 40 CFR 122 (chapters 26 and 20 through 37). 

Stormwater Management Plan

The Public Works Department (DPW) developed a Stormwater Management Plan (SWMP) to define policies and procedures by which the Town’s MS4 is operated and support the Town in meeting the Phase II permit requirements. The SWMP accurately describes the Tonw’s plans and activities. The document is updated and/or modified during the permit term as the Town’s activities are modified, changed or updated to meet permit conditions during the permit term.

Drainage System Management

The DPW manages the Town’s storm drain system. This system, also known as the drainage system, includes about over 40 miles of drainage pipe connecting to 2,400 catch basins (also called drains) and 800 drainage manholes. 

The drainage system handles only stormwater runoff and carries rainwater from the roadway to outfalls at brooks, ponds, rivers, and wetlands. This is why it is so important for the water going into the drains to be clean. In addition, there are also 20 miles of private roads including drainage systems for which the town has no control over the maintenance or upkeep.

Minimum Control Measures

In addition to other requirements, in order to comply with the program, Weston must follow 6 Minimum Control Measures, which are implemented through a series of Best Management Practices (BMPs). 

The primary components of the stormwater management program include:

  • public education and outreach 
  • public involvement and participation 
  • illicit discharge detection and elimination
  • construction site stormwater runoff control
  • post-construction stormwater management
  • pollution prevention and good housekeeping

Additional Information

To learn more about the U.S. EPA NPDES Phase II Program in New England, please visit the EPA website for a series of fact sheets.

For more information regarding the Phase II Stormwater Management Program in Weston, contact Stephen Fogg, Weston Town Engineer at 781-786-5115.