Navy Agrees to Comply with Clean Water Act for Munitions Testing on Potomac

Federal Court in Maryland Approves Settlement in Lawsuit Brought by Potomac Riverkeeper Network and NRDC 

WASHINGTON, DC  – The U.S. Navy has settled a Clean Water Act lawsuit filed by Potomac Riverkeeper Network (PRKN) and NRDC (the Natural Resources Defense Council) over the Navy’s pollution of the Potomac River through a century of munitions testing. A federal court in Maryland today approved a consent decree requiring the Navy to apply to the Maryland Department of the Environment for a permit within 30 days, resolving claims by PRKN and NRDC that the Navy’s unpermitted discharges of cannon shells, chemical warfare simulants and other munitions into the river violate the Clean Water Act. A permit under the Clean Water Act would require the Navy to meet the state’s water quality standards for the Potomac and conduct monitoring sufficient to ensure compliance.

Throughout a 51 nautical mile stretch of river designated part of the Potomac River Test Range, the Navy fires small arms and large-caliber guns, detonates explosives, and tests lasers, propellants, and targeting systems. In a remarkable artifact of World War I era testing, the Navy has been discharging these munitions since 1918—more than 33 million pounds worth—into the Potomac, 53 miles south of Washington DC. The munitions contain toxic metals, solvents, explosives, and other potentially harmful constituents.  The testing takes place on land, in laboratories and in the Potomac River itself.  Until now, the program’s discharge of munitions into the river has never been regulated under the Clean Water Act.

Watermen, oystermen, recreational anglers and commercial watercraft operators welcomed the Navy’s promise to comply.

As a Virginia waterman, I am concerned about water quality and how it could impact our fish and crabs that enable our livelihoods,” said Michael Lightfoot, member of the Virginia Waterman’s Association and Twin Rivers Watermen’s Association. “I depend on high water quality to make a living and I rely on Maryland, Virginia and the Potomac Riverkeeper Network to enforce and ensure our water quality in the Potomac River.”

“The Navy’s coming into compliance with the Clean Water Act will sustain the public’s ability to safely use and enjoy the Potomac.” said Dean Naujoks, Potomac Riverkeeper. “We will work in the state process to ensure that Maryland issues a permit that fully protects water quality in the river.” 

Upon earlier request by PRKN and NRDC, the Navy had already agreed to voluntarily reinitiate consultation with the National Marine Fisheries Service (NMFS) over potential harms to the habitat for the endangered Atlantic sturgeon, which spawns and migrates in these waters. It has begun conducting a biological study on this special species, known as the ‘dinosaur’ of fish. The initial complaint in the lawsuit, filed in June 2023, is available here.


NRDC (Natural Resources Defense Council) is an international nonprofit environmental organization with more than 3 million members and online activists. Established in 1970, NRDC uses science, policy, law, and people power to confront the climate crisis, protect public health, and safeguard nature. NRDC has offices in New York City, Washington, D.C., Los Angeles, San Francisco, Chicago, Bozeman, MT, Beijing and Delhi (an office of NRDC India Pvt. Ltd). Visit us at www.nrdc.org and follow us on Twitter @NRDC. 

Potomac Riverkeeper Network is a registered 501(c)3 non-profit organization with three regional Waterkeeper branches: Potomac Riverkeeper, Upper Potomac Riverkeeper, and Shenandoah Riverkeeper. Our mission is to protect the public’s right to clean water in the Potomac and Shenandoah Rivers and their tributaries. We stop pollution to enhance the safety of our drinking water, protect healthy river habitats, and enhance public use and enjoyment.

Related Press Releases