LEESPORT, PA -- The U.S. Army Corps of Engineers’ (USACE) Philadelphia District at Blue Marsh Lake will be reopening the swim beach for Saturday, July 19, 2025, however the Harmful Algal Bloom (HAB) Status will remain within the Warning Status.
The update to the swim beach status does not eliminate the risks associated with harmful algae. Please be aware of the presence of moderate to high levels of cyanobacteria, also known as blue-green algae, in the lake and the detection of harmful toxins. Visitors are advised to be alert for harmful algal bloom conditions and avoid contact with the water.
The designated swimming area at the Dry Brooks Day Use Area is the only location at the lake that is monitored and tested on a weekly basis. Tests from this week have indicated toxin levels from the cyanobacteria have fallen within safe standards to allow the swim beach to be reopened. However, these tests only represent conditions at the time of testing and can change rapidly. Test results from other areas of the lake during monthly reservoir monitoring activities currently indicate high levels of cyanobacteria and the presence of high levels of the harmful toxins produced by the algal blooms occurring within the lake.
To protect yourself, your family, and your pets from blue-green algae blooms:
- Learn about and know the signs and symptoms of harmful algal bloom, such as extremely discolored water, foam, scum, or mats of algae. When in doubt, stay out.
- Avoid water contact where the water is discolored or where you see foam, scum, or mats of algae on the water’s surface.
- Children and pets are especially susceptible to the harmful effects of the toxins produced by cyanobacteria. Do not allow children or pets to play in or drink discolored or scummy water.
- If you have contact with water that might contain harmful cyanobacteria, rinse off with fresh water as soon as possible afterwards.
- Learn more about Harmful Algae Blooms and their associated risks and current lake statuses by visiting: https://www.nap.usace.army.mil/Missions/Civil-Works/Blue-Marsh-Lake/Harmful-Algal-Bloom-Information/
- Tests for various locations submitted to PA DEP for in depth analysis can be viewed on the Pennsylvania HAB Task Force’s PA HAB Dashboard at: https://www.arcgis.com/apps/dashboards/9b653809b2724ff299dc1b5b3d1c546b
For additional information, please contact the Park Office at 610-376-6337.
Release no. 25-018