EPA Region 1 issued a formal postponement, on June 29, of the effective date (July 1) of the general National Pollutant Discharge Elimination System (NPDES) permit for small municipal separate stormwater systems (MS4s) in Massachusetts.  The permit is currently being challenged in the U.S. Court of Appeals for the District of Columbia by a group that includes Massachusetts municipalities, the National Association of Homebuilders, and environmental groups. The delay postpones the effective date of the permit until July 1, 2018, to allow for judicial proceedings and suggests that EPA would like to explore as a possible settlement.

The permit requires strict compliance with water quality standards (WQS), and imposes specific obligations on municipal separate stormwater systems (MS4s) to meet this requirement. These provisions represent a significant shift from the Clean Water Act (CWA) mandate that MS4s reduce the discharge of pollutants to the “the maximum extent practicable (MEP)" through the implementation of best management practices.  Instead, the permit includes compliance with WQS as an additional obligation, and prescribes measures that MS4s must follow to comply with the permit.  The permit also imposes a requirement on regulated MS4s to impose a numeric flow-related (retention) standard on new development and redevelopment within their communities.

NACWA has a long history of defending the MEP standard in litigation as the appropriate standard for MS4 compliance, dating back to the 1990s, and the forthcoming court of appeals’ decision will squarely address the extent and limits of federal CWA authority on this issue.  In March, the NACWA Board approved the filing of a joint amicus curiae brief in cooperation with The Wet Weather Partnership, to provide an important national perspective for issues crucial to MS4s.

EPA Region 1 also issued a nearly identical permit for small MS4s in New Hampshire, which has also been challenged in federal court.  Because of the similarities in the permits, the DC Circuit has delayed briefing in the Massachusetts permit challenge to allow for parallel proceedings with the New Hampshire permit.  According to EPA’s postponement memo, delaying implementation of the Massachusetts permit will allow the parties to explore alternative dispute resolution in both cases, and to align requirements and effective dates for both states.