MDE Finds No Shellfish Contamination in Prince George's Potomac; Closure Lifted March 10

The Maryland Department of the Environment announced Feb. 25 that state water-quality and shellstock testing show no evidence that shellfish harvesting waters of the Potomac River in Maryland were affected by the Jan. 19 Potomac Interceptor breach, and the agency set a precautionary shellfish-harvest closure to be lifted on March 10, 2026 while monitoring continues. The agency’s public statement framed the results under the headline, “Maryland Department of the Environment Releases Latest Sampling Results Maintaining Positive Shellfish Conditions After Potomac Interceptor Spill,” and MDE posted on social media, “🌊🦀 Recent testing by the Maryland Department of the Environment (MDE) confirms there is no evidence that Maryland shellfish have been affected.”

Local reporting and agency materials place the late-February sampling window in Charles County and Prince George’s County, where MDE conducted shellstock testing and collected river water samples. Somdnews reported that the state-collected samples indicated bacteria levels that would meet water quality standards for recreational contact, a finding that underpins the March 10 lift date announced by MDE. Maryland officials also said that water quality monitoring is ongoing.

The Potomac Interceptor breach occurred Jan. 19 along Clara Barton Parkway in Montgomery County; the interceptor is a large sewer line owned and maintained by D.C. Water. Maryland’s Feb. 20 update described the agency’s role supporting the regional response to restore service and protect waterways. On the Virginia side, the Virginia Department of Health issued recreational use advisories on Feb. 13; local reporting cited an official named Naujoks saying those advisories could be lifted by March 2, and Naujoks warned, “If you’re going to restore the public faith and confidence to come back and use the river, it’s going to require a lot of testing and data and a lot of reassurances.”

Charles County commissioners moved on testing and local oversight on Feb. 24 when they approved a letter requested by Commissioner Gilbert “BJ” Bowling asking MDE, the Metropolitan Washington Council of Governments, the Southern Maryland Tri-County Council and other agencies to conduct bi-weekly water quality testing from the county line at Bryans Road to Cobb Island. Bowling told the county meeting, “It’s impacting the watermen’s ability to make a living and the health and the safety of the river for recreational purposes. Our economy … relies heavily on the waterways.” Bowling also stressed investments in oyster restoration, saying, “I don’t want to lose track of the progress we made,” as watermen have reported increased shellfish harvesting and oysters play a role in filtering the river.

Somdnews underscored the stakes for the ecosystem and local economy, noting concerns about massive fish kills and harmful algal blooms and explaining that, “Unlike oil spills, sewage cannot be removed from the water. Instead, it fills the area with E. coli and other bacteria, putting the environment, watermen and other residents at risk.” Local reporting also stated, “No drinking water has been affected, according to officials.”

For broader water-quality context, University of Maryland School of Public Health reporting on the WATER Study highlights gaps between regulated municipal systems and private wells and notes ongoing concerns about persistent contaminants. The study team said, “The preliminary data suggest drinking water in Maryland is generally safe. The at-home test kits showed small percentages of households with various harmful contaminants,” and researchers warned, “We are still analyzing samples but we expect to see the presence of ‘forever chemicals’, consistent with other research and possibly heavy metals and antimicrobial-resistant bacteria.” The report added that PFAS have been found in at least 45 percent of American drinking water sources and have been shown to increase the risk of cancer by a third.

MDE’s March 10 lift date is a near-term milestone, but testing will continue between now and then and Charles County is pushing for bi-weekly sampling in the Bryans Road to Cobb Island corridor. Outstanding technical questions remain about the number and location of samples, laboratory results and whether the March 10 action is conditional on additional confirmation testing. Residents, commercial watermen and recreational harvesters should watch Maryland Department of the Environment releases and county announcements for confirmation of the closure lift and any site-specific harvesting guidance ahead of March 10, 2026.