Pennsylvania warns against eating fish from Wissahickon basin

Pennsylvania officials are advising people not to eat any fish caught in the Wissahickon Creek basin after sampled fish tissue exceeded the state’s PFOS threshold. The Department of Environmental Protection, Department of Health and Fish and Boat Commission issued the advisory Oct. 7, 2026.

The advisory applies to all fish species throughout the basin in Montgomery and Philadelphia counties. It concerns eating fish, not fishing: the creek remains open to anglers, according to WHYY.

Reported PFOS levels exceeded the state threshold

The state’s Do Not Eat advisory level is 0.04 parts per million, equivalent to 40.0 nanograms per gram. The agencies said sampled fish tissue exceeded that level. The state announcement did not state the exact highest result.

The Philadelphia Inquirer reported that a Department of Environmental Protection spokesperson gave the highest result as 0.0567 parts per million. WHYY reported a rounded maximum of 0.05 parts per million. Both reported figures are above the state threshold, though they differ in precision.

The Inquirer reported that sampling included archived tissue collected from 2013 through 2021 near Fort Washington State Park. WHYY reported that the Department of Environmental Protection had not identified the source of PFOS in the watershed.

One Philadelphia stocking was canceled

The Fish and Boat Commission canceled a trout stocking scheduled for Oct. 15, 2026, on Wissahickon Creek Section 04 in Philadelphia. The cancellation applies to that scheduled stocking; it is not an announcement ending trout stocking throughout the basin.

A commission spokesperson told the Inquirer that sampling in only one or two locations may lead to an advisory covering an entire basin, and raised concerns about what basin-wide advisories could mean for trout stocking. That is the spokesperson’s concern, not a finding that the sampling was inadequate.

WHYY reported that the commission is considering possible approaches to future stocked-trout management, including stocking only sections considered unaffected or requiring catch-and-release. Those are options under consideration, not adopted rules. The Oct. 15 cancellation is the specific stocking change announced so far.

The commission scheduled a public meeting for Nov. 5, 2026, from 6 to 7 p.m. at the Schuylkill Center for Environmental Education, 8480 Hagy’s Mill Road in Philadelphia, to gather input on future stocked-trout management. No new management policy was established in the advisory announcement.

For people who catch fish in the basin, the current guidance is not to eat any species caught there. Fishing remains open, while the commission’s approach to future stocked-trout management remains under consideration.