Free Pennsylvania water report: PFAS & lead levels for every water system, worst-affected cities, and EPA violations. Check your ZIP.
Pennsylvania's 13 million residents are served by a complex patchwork of water utilities drawing from rivers, reservoirs, and groundwater across a geographically diverse state. Philadelphia pulls from the Delaware and Schuylkill rivers, Pittsburgh from the Allegheny and Monongahela, and smaller cities and towns rely on local surface water or groundwater wells. The state has over 8,000 public water systems – one of the highest counts in the nation – reflecting Pennsylvania's fragmented municipal governance. The Pennsylvania Department of Environmental Protection (DEP) oversees drinking water regulation in a state with a deep industrial legacy and an increasingly well-documented PFAS contamination problem, particularly in the southeastern counties.
Pennsylvania's PFAS contamination is concentrated most severely in Bucks and Montgomery counties in the southeastern part of the state, where military installations have left extensive groundwater contamination. The former Naval Air Warfare Center Warminster (NAWC Warminster) and the former Naval Air Station Joint Reserve Base Willow Grove used AFFF for decades, and PFAS plumes from these facilities have contaminated public and private water supplies in the surrounding communities of Warminster, Warrington, Horsham, and neighboring townships.
The contamination in these communities has been extensively documented and is among the most studied military PFAS sites in the country. Tens of thousands of residents were affected, and the Navy and Air Force have provided bottled water, connected homes to public water, and installed treatment systems in response. Despite these actions, cleanup is ongoing and some contamination plumes continue to migrate.
Beyond the Bucks County hotspot, PFAS has been detected at military and industrial sites across the state. Pennsylvania has been aggressive on testing – the state launched one of the earliest statewide PFAS sampling programs for public water systems and has maintained an extensive monitoring effort. However, Pennsylvania has been slower to adopt enforceable state-specific MCLs, relying on the federal EPA standards of 4 parts per trillion for PFOA and PFOS while developing its own rulemaking.
The EPA's UCMR5 data combined with Pennsylvania DEP's own testing program provides extensive coverage. Our data integrates federal, state, military, and utility-level monitoring for address-specific results.
Pennsylvania is among the most PFAS-aware states in the country, driven by the severity of the Bucks County contamination and sustained community advocacy in affected areas. The state's testing program has been exemplary, generating data that other states have used as a model. Where Pennsylvania falls behind leaders like New Jersey and New Hampshire is in converting that data into enforceable standards – the state has proposed PFAS MCLs but the rulemaking process has moved slowly.
Compared to neighboring New Jersey, which adopted enforceable PFAS MCLs years earlier, Pennsylvania has better data but weaker regulatory teeth. Compared to New York, Pennsylvania covers a broader geographic area of contamination but has a less developed enforcement framework. The Bucks County military contamination cluster is one of the most significant in the nation, comparable in scale and impact to the contamination around Pease ANGB in New Hampshire or Peterson AFB in Colorado.
Pennsylvania also faces legacy contamination from its industrial history – steel production, coal mining, chemical manufacturing, and petroleum refining left contaminants in waterways and groundwater that predate and overlap with PFAS concerns.
Pennsylvania's water quality varies significantly by region and by the size and type of your water system. Southeastern Pennsylvania faces the most documented PFAS contamination, but detections have been found statewide.
1. Check your water quality using our free lookup tool. We map Pennsylvania DEP data, UCMR5 results, military testing, and utility reports to your ZIP code. 2. If PFAS is present, a reverse osmosis system provides the most reliable removal – over 90% for most PFAS compounds. Residents in the Warminster/Warrington/Horsham area should verify that any public water treatment installed by the military is covering their specific supply. Our water filter guide compares point-of-use systems by independent lab data. 3. Private well owners, particularly in Bucks, Montgomery, and Chester counties, should test their water if they have not already. Request a detailed water report for your address.
For more on PFAS science, see our PFAS guide.
Pennsylvania's environmental history is as old as American industry itself. The state was the cradle of the petroleum industry (the first commercial oil well was drilled in Titusville in 1859), a center of steel production, and a major coal mining state. Each of these industries left contamination legacies – acid mine drainage from coal operations still affects thousands of miles of Pennsylvania streams, and industrial waste sites dot the landscape from Philadelphia to Pittsburgh.
The Bucks County PFAS contamination came to public attention around 2014 when testing near the former military bases revealed PFOS and PFOA in public water supplies and private wells at levels that alarmed health officials. The affected communities organized quickly, and groups like the Bucks County PFAS Contamination Coalition became some of the most effective community advocates in the national PFAS conversation.
The Navy and Air Force have spent significant resources on remediation in the area, including installing granular activated carbon treatment at public water systems, connecting private well users to treated public water, and conducting ongoing groundwater monitoring. But the contamination plumes are large and complex, and full cleanup will take years if not decades.
Pennsylvania's DEP launched its statewide PFAS sampling initiative in 2019, testing hundreds of public water systems and identifying detections across the state. The data generated has been valuable but has also highlighted the gap between knowing where contamination exists and having enforceable standards to compel treatment. The state's PFAS MCL rulemaking is underway but faces the same regulatory complexity and industry pushback seen in other states. Check your specific address to see the latest monitoring data for your area.