Advisory issued after ‘forever chemicals’ detected in stream and pond

Montgomery County officials on Monday warned about high levels of “forever chemicals” in a pond and stream near Great Seneca Highway.

A “contact water advisory” has been issued for the Muddy Branch stream and a pond it feeds into at the corner of the highway and Key West Avenue. People and their pets should avoid swimming, fishing and touching the water.

The Maryland Department of the Environment informed the county that high levels of perfluoroalkyl and polyfluoroalkyl substances, known as PFAS, had been detected in the water, county officials said a press conference Monday.

PFAS are synthetic chemicals used in a wide variety of products, including nonstick cookware and adhesive bandages.

Research has shown that long-term exposure may increase the risk for certain types of cancer.

The local contamination presents no threat to drinking water, said Laura O’Donnell, of WSSC Water, which supplies drinking water to most Montgomery County residents.

The highest concentrations of the PFAS were found adjacent to and on the site of the former Montgomery County Public Safety Training Academy, according to county officials. Firefighting foam containing PFAS was used there for decades until it the state legislature banned it in 2021.

Officials say the contamination is concentrated around the pond and sections of Muddy Branch, with significantly lower levels in surrounding areas.

Kisha Davis, the county’s health officer, said at the press conference that brief contact with contaminated water does not increase the risk from PFAS.

“The health risks are tied to chronic exposure, meaning drinking contaminated water or eating contaminated fish every day for years, which allows the chemical to gradually accumulate in the body’s tissues,” Davis said.

The county has begun notifying nearby residents and businesses, posting warning signs and offering free testing for private wells within a one-mile radius of the most contaminated areas.

Officials will host a series of in-person and virtual community meetings on the contamination. The first event, at DuFief Elementary School, will take place at 7 p.m. on Wednesday.