PFAS contamination in streams and ponds near the former Public Safety Training Academy in North Potomac exceeds federal drinking-water benchmarks by hundreds of times, according to Montgomery County government data.

The Maryland Department of the Environment sampled 10 locations in two rounds, November–December 2025 and March–April 2026. Every site came back above the EPA's National Drinking Water Standard for PFAS, a group of synthetic chemicals sometimes called "forever chemicals."

The worst readings came from two sites closest to the former academy on Great Seneca Highway. At sampling point MB8, near a stormwater pond, MDE found PFOS at 1,600 parts per trillion. The federal limit is 4 parts per trillion. PFOA hit 439 parts per trillion at the same site, against a 4-part-per-trillion standard. A third compound, PFHxS, measured 1,240 parts per trillion, 124 times the 10-part-per-trillion benchmark.

The county attributes the contamination to Class B firefighting foam, known as AFFF, used for training at the academy from the late 1970s until 2015. The county stopped using PFAS-containing foam entirely in November 2020.

Montgomery County Health Officer Dr. Kisha Davis issued a public health advisory on June 15 for a section of the Muddy Branch stream watershed and surrounding ponds. Residents and pets should avoid water contact and refrain from fishing from Blackwell Road down to the confluence of mainstem Muddy Branch, including a small stream running along the south side of Great Seneca Highway and beneath Key West Avenue.

WSSC Water has confirmed that treated drinking water from the Potomac River remains in compliance with federal PFAS standards. The county is contacting private well owners within one mile of the highest readings to offer free testing.

The West Montgomery County Citizens Association's October newsletter, published Oct. 7, flagged a concern that testing so far covers only the area near the academy. "Scientists have found that decades of PFAS foam use in other states have created underground plumes that migrate several miles," the newsletter stated. A multi-agency task force including the county Department of Environmental Protection, MDE, WSSC Water and Montgomery County Parks is overseeing the response.

The EPA numbers used as benchmarks are drinking-water standards, not surface-water standards. No federal standard exists for PFAS in streams and ponds. The county uses the drinking-water limits as the closest available health-based comparison.

Montgomery County filed a federal lawsuit in May 2023 against PFAS manufacturers, seeking to hold them responsible for contamination and remediation costs.

Elrich warns Starter Homes Act may return

Separately, the WMCCA newsletter reported that County Executive Marc Elrich warned members of the Montgomery County Civic Federation in September that the Moore administration intends to bring back the Starter and Silver Homes Act in some form.

The bill, introduced as SB 36/HB 239 in the 2026 General Assembly session, would have allowed townhouses on single-family-zoned lots and barred local governments from requiring minimum lot sizes above 5,000 square feet in areas with water and sewer, WYPR reported. It died in committee after opposition from civic groups in Montgomery and Prince George's counties.

WMCCA member Ginny Barnes, who wrote the newsletter section on the issue, called the prospect "devastating to low density zoned Master Plans like the Potomac Subregion where environmental protection is key."

No new bill has been introduced. The next opportunity would come in the 2027 General Assembly session, which begins in January. The Civic Federation said it is monitoring and researching the issue.

WMCCA's next general meeting is Tuesday, Oct. 13, at 7:15 p.m. at the Potomac Library. The theme is "You — Bring Your Concerns," an open community discussion.