Poolesville closed two municipal wells after detecting PFAS contamination | The Locally Times
The town removed Wells 2 and 3 from service following Maryland Department of the Environment testing.
The Town of Poolesville closed municipal Wells 2 and 3 after water quality testing confirmed the presence of per- and polyfluoroalkyl substances (PFAS). The Maryland Department of the Environment (MDE) sampled 137 community water systems and identified the Poolesville system as requiring risk mitigation due to elevated levels of PFOA and PFOS compounds. Following the test results, the town mailed a Tier 2 Public Health Advisory Notice to residents. The Environmental Protection Agency (EPA) set interim health advisory levels for PFOA and PFOS at 0.004 parts per trillion (ppt) and 0.02 ppt respectively. Current laboratory testing technology uses a minimum reporting level (MRL) of 4 ppt, meaning equipment cannot measure down to the specific federal health advisory thresholds. ## Filtration Testing The town installed carbon-activated charcoal filtration units at Well 3 and bench-top corn-based filtration units at Wells 2 and 3. The town is collecting data on removal rates, operational costs, and maintenance requirements for these media types. The MDE will check these results to determine if the town can return Well 3 to active service. The town submitted grant applications to fund water treatment infrastructure upgrades. ## Treatment Expansion The shutdown of Wells 2 and 3 follows state assessments of water safety. The town plans to use data from the filtration testing to evaluate whether to expand treatment protocols to other municipal wells. The town has not disclosed the specific impact of the well closures on total water capacity or potential service restrictions as of June 21, 2026. ## Key Questions **Why were the wells shut down?** The Town of Poolesville removed Wells 2 and 3 from service after state-mandated testing detected elevated levels of PFOA and PFOS. **When will the wells be back in service?** Well 3 will return to service only after the MDE check the pilot program data and approves the water safety. The town has not set a date for the return of either well. **How can I learn more about my water safety?** Residents should check the Tier 2 Public Health Advisory Notice mailed to their homes and monitor the official Town of Poolesville website for updates.