Update – 9/5/26: The U.S. Army Corps of Engineers Philadelphia District has announced that the Swim Area at the Dry Brooks Day Use Area, Blue Marsh Lake, has been reopened. Bacteria readings for the designated swimming area have returned to safe levels. The swim beach has been re-opened as of September 5, 2026 at 8AM.
Original post: The designated swim beach at Blue Marsh Lake has been temporarily closed after testing detected elevated bacteria levels, the U.S. Army Corps of Engineers Philadelphia District announced Friday.
The closure affects the swimming area at the Dry Brooks Day Use Area, where high levels of E. coli were detected above safe recreational standards.
According to the Army Corps of Engineers, the closure is limited to the designated swim beach. The picnic area and boat launches remain open for recreational use.
Officials said testing will be conducted daily to monitor bacteria levels. The swim beach will reopen once testing shows that levels have returned to safe recreational standards.
No reopening date has been announced.
