Maryland health officials announced the lifting of recreational water advisories for the Potomac River in Prince George’s and Charles counties, following the January 19 Potomac Interceptor sewage spill. The decision comes after consistent water quality testing by the Maryland Department of the Environment showed bacteria levels at acceptable standards for recreation in those areas. Montgomery County’s advisory remains in effect due to elevated bacteria near the spill site in that jurisdiction. A precautionary shellfish harvesting closure in parts of Charles County is set to lift March 10, pending final tests confirming no impact from the upstream event.
The spill occurred when a 72-inch sewer main, owned and operated by DC Water, ruptured in Montgomery County, releasing an estimated 243 million gallons of untreated wastewater into the Potomac River. DC Water contained the overflow, with the last significant release reported February 9. The line transports sewage from Northern Virginia to the Blue Plains Wastewater Treatment Plant in Washington, D.C. The incident prompted immediate closures and advisories across Maryland, Virginia, and D.C. to protect public health.
Maryland’s Department of Health, coordinating with local health departments and state agencies, based the lifting of advisories in Prince George’s and Charles counties on MDE sampling results. Prince George’s lifted its January 25 advisory immediately, citing acceptable bacteria levels in county-specific Potomac River samples. Charles County followed suit on the same basis. St. Mary’s County never required an advisory, as it remained outside the affected plume, with routine sampling confirming safe conditions for recreation and shellfish.
Montgomery County’s January 29 advisory continues, reflecting proximity to the spill on federal land and ongoing elevated bacteria readings. Officials will monitor further results to determine next steps. Public drinking water supplies across the region stayed unaffected throughout the response.
For shellfish, MDE imposed a precautionary closure January 25 on a 60-mile downstream stretch in Charles County, from the Port Tobacco River region to the U.S. Route 301 bridge. Recent testing, including post-thaw sampling, found fecal coliform levels well below national standards for approved shellfish harvesting. No evidence emerged of impacts to shellfish waters, and the closure—more stringent than recreational standards under the National Shellfish Sanitation Program—will end March 10 after confirmation. This program involves rigorous water quality testing, harvesting reviews, and enforcement by agencies including Maryland Natural Resources Police. Oysters currently on the market come from approved Chesapeake Bay areas, tagged for traceability, and remain unaffected.
The Potomac River Fisheries Commission, in a joint statement with Maryland agencies, confirmed the river portion under its jurisdiction stays open for fishing. Crabbing will proceed as scheduled when the season opens, with no evidence of harm to fish or shellfish populations. Anglers and boaters in Prince George’s and Charles counties can now resume activities, following Maryland Department of Natural Resources regulations on species limits.
D.C. lifted its recreational advisory March 2 after weeks of low bacteria levels meeting EPA standards. Virginia partially lifted portions of its advisory, though some upstream sections remain restricted.
The District of Columbia secured a presidential emergency declaration February 21 for federal assistance in repairs and cleanup. Maryland’s Department of Natural Resources continues collaboration with involved agencies to assess any lingering risks, prioritizing public health and environmental protection.
General guidance urges caution with natural waters: avoid contact in impacted zones, keep pets away, wash after exposure, and seek medical help for symptoms like vomiting or rash. Those at higher risk—young children, older adults, and immunocompromised individuals—face greater vulnerability to waterborne illnesses.