MS4 Permit Campaigns

What is an MS4 Permit?

Governments that maintain a storm drain system are issued a federal Clean Water Act permit known as an MS4 (municipal separate storm sewer system). This MS4 permit regulates discharges from the storm sewer system into local waterways. These permits are one of the primary regulatory and enforcement tools of the Clean Water Act. The District of Columbia and Montgomery and Prince George’s Counties are all MS4 jurisdictions, and advocacy around these permits is an important part of AWS’s work.

Montgomery County MS4 Permit

Five years of advocacy by AWS and its allies in the Montgomery County Stormwater Partners resulted in Montgomery County being issued the first of a new, stronger wave of Maryland MS4 permits in 2010. This permit required that Montgomery retrofit 20% of its existing impervious surfaces in every 5 year permit cycle, until all impervious surfaces have adequate stormwater runoff controls.

However, we and many of our fellow water quality advocates feel that this permit is not strong enough. In 2013, some of our partners filed a petiton with the Montgomery County circuit court on the grounds that the permit is flawed, does not move us closer to meeting water quality standards, and does not provide adequate opportunities for public involvement. The court ruled on the side of the advocates and required that Maryland Department of the Environment (MDE) improve the permit on those grounds. MDE appealed this court's decision and the case was heard by Maryland Court of Special Appeals which ruled against MDE in April 2015 and sent the permit back to the state’s environmental regulators. We expect big changes in the next propsed permit from MDE and that this action will start the change needed on other county permits. 

Prince George's County MS4 Permit

When the 2010 Montgomery permit was finalized, MDE committed to using that permit as a “floor” for all future MS4 permits in the state.  In other words, every subsequent permit issued would be at least as strong as the Montgomery permit. Prince George's County's 2009 permit needed vast improvements and though we are making gains in getting changes made, we still are not seeing what is needed in order for the county to meet water quality standards. Soon after the 2014 permit was released in January, we joined our partners in filing a petition to require the state to strengthen permit requirements.

DC MS4 Permit

DC’s unique legal status means that EPA Region 3 issues the permit directly to the District. AWS and its allies have worked on this permit for several years, and a fairly strong five-year permit was issued in September 2011. The permit improved restrictions on polluted stormwater discharges and requires more green infrastructure. For development projects that disturb an area of 5,000 square feet or more, stormwater controls must achieve onsite retention of 1.2” of stormwater (one of the highest standards in the region).

In November 2011, some of our partners filed a joint petition requesting that the Environmental Appeals Board review the permit to improve its implementation and provide the public with opportunities to provide input. DC Water and the Wet Weather Partnership (WWP) also jointly filed a similar but separate petition at that same time. In May 2012, our partners and the EPA settled on an agreement which resulted in the following changes to the permit 1) the public recieved more notification and was given additional opportunities to provide input on DC's Consolidated TMDL Implementation Plan (a requirement of the 2011 permit), 2) more accountability and better clarification for some of the water-quality outcomes were given, 3) the DC government is listed as the only permittee. 

DC's Consolidated TMDL Implementation Plan was released for public comment in May 2015. We submitted comments in collaboration with some of our partners and are awaiting responses and a final plan.




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