NPDES MS4 Permit
The 2016 Massachusetts Small MS4 General Permit was signed April 4, 2016 and will become effective July 1, 2018.
An MS4 is a conveyance or system of conveyances that is:
- owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.,
- designed or used to collect or convey stormwater (e.g., storm drains, pipes, ditches),
- not a combined sewer, and
- not part of a sewage treatment plant, or publicly owned treatment works (POTW).
The Clean Water Act authorizes EPA to regulate point sources that discharge pollutants into waters of the United States through the National Pollutant Discharge Elimination
Point sources are generated from a variety of municipal and industrial operations, including treated wastewater, process water, cooling water, and stormwater runoff from drainage systems. The NPDES Stormwater Program, in place since 1990, regulates discharges from municipal separate storm sewer systems (MS4s), construction activities, industrial activities, and those designated by EPA due to water quality impacts.
To prevent harmful pollutants from being washed or dumped into specific types of MS4s, operators might be required to obtain NPDES permits and develop stormwater management programs (SWMPs).
In order for a small MS4 operator to obtain authorization to discharge, it must submit a complete and accurate Notice of Intent (NOI). A small MS4 operator must meet the eligibility requirements of the general permit prior to submission of its NOI. A small MS4 operator will be authorized to discharge under the permit upon receipt of written notice from EPA following a public notice of the submitted NOI.
Owners/operators of regulated municipal separate storm sewer systems (MS4s) are required to develop, implement, and enforce a stormwater management program (SWMP). The focus of the SWMP is to describe how the MS4 will reduce the discharge of pollutants from its sewer system and addresses these program areas:
- Construction Site Runoff Control
- Illicit Discharge Detection and Elimination
- Pollution Prevention/Good Housekeeping
- Post-Construction Runoff Control
- Public Education and Outreach
- Public Involvement/Participation
- Program Effectiveness
- Total Maximum Daily Loads