County warns of recent Potomac drownings, issues PFAS water‑contact advisory near Great Seneca Highway

Montgomery County Executive Mark Eldridge warned residents about two recent drowning deaths in the Potomac River over the holiday weekend, including a 16‑year‑old who drowned near Great Falls Park, and reiterated that swimming in the Potomac is illegal and dangerous.

"I wanna remind everyone that it is illegal to swim in the Potomac River. It's also really dangerous to swim in the Potomac River," Eldridge said, asking residents to favor county pools and other supervised facilities.

Eldridge also announced a water‑contact advisory for parts of a stormwater pond and a small stream near Great Seneca Highway and Key West Avenues after tests found elevated levels of PFAS, a group of synthetic chemicals that persist in the environment. Officials said the sites with elevated PFAS are not drinking‑water collection points and that WSSC Water has confirmed drinking water drawn from the Potomac meets current federal PFAS standards.

"Out of an abundance of caution, we recommend staying away from water and washing thoroughly with soap and clean water if you, your pets, or your children are exposed," Eldridge said. He added that Montgomery County and the Maryland Department of the Environment will continue testing water, soil and groundwater and that a county interagency task force is coordinating work.

County officials said private well owners in the area have been contacted about testing and provided the county PFAS information webpage and 311 as resources for questions.