Maryland’s Municipal Separate Storm Sewer System (MS4) Permits

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Maryland Court Rules in Favor of Local Riverkeepers and Rejects Weak Montgomery County Stormwater Permit

On April 2, the Maryland Court of Special Appeals ruled against the Maryland Department of Environment (MDE) and sent the flawed stormwater permit for Montgomery County back to the state’s environmental regulators, citing a laundry list of legal and factual shortcomings that violated state and federal law. The court’s April 2 order upholds a 2013 […]


Stormwater runoff from streets, parking lots and other impervious surfaces in urban and suburban areas carries fecal bacteria, oil, chemicals, trash and nutrients from sediments into storm sewers that carry this polluted water directly to nearby waterways. The result is degraded water quality that fails to meet minimum standards for protection of aquatic wildlife or recreational uses like canoeing, kayaking and swimming. To solve it, local governments need to work with businesses and residents to do a few basic things – screen out the big stuff like trash and debris, capture and alter the water to remove pollutants before they are dumped into these waterways, and monitoring to make sure the measures are working as planned.

The detailed plan on how to do this should be contained in what’s called an “MS4” Permit, issued and overseen by the Maryland Department of the Environment (MDE). Unfortunately, MDE and several Counties did their best to avoid the details, timelines and verification, and instead tried to pass off a permit that was at best, a “plan to make a plan” sometime in the future, without enough meat on the bones for the public to provide useful input. Their recalcitrance is bad public policy, and an insult to businesses and homeowners in our region who have voluntarily made efforts to reduce their stormwater impact. In addition, MS4 permits must include specific, verifiable requirements for reducing stormwater runoff into local waterways and meeting the EPA’s standards for reducing downstream pollution to the Chesapeake Bay.

Status Update: We filed suit against Montgomery County MS4 permit in late 2010 and against the Prince George’s County MS4 permit in early 2014. We were joined in our legal challenges by other local Waterkeepers and other groups, and represented by Earthjustice. Similar challenges to equally lousy permits were led in at least five other counties by Chesapeake Bay Foundation and other groups, all with a simple goal: compel Maryland regulators to write strong permits to improve water quality. In March 2016, the Court of Appeals upheld Montgomery County, Prince George’s County, Balitmore County and the City of Baltimore MS4 permits. Earthjustice’s Motion for Reconsideration was denied in May 2016.