Free Massachusetts water report: PFAS & lead levels for every water system, worst-affected cities, and EPA violations. Check your ZIP.
Massachusetts delivers drinking water to approximately 7 million residents through one of the more complex and well-regulated water systems in the country. The Massachusetts Water Resources Authority (MWRA) supplies wholesale water to over 50 communities in the greater Boston area, drawn from the Quabbin and Wachusett reservoirs in central Massachusetts – a protected watershed system that produces water clean enough to avoid filtration requirements (one of only a few large systems in the US with this distinction). Outside the MWRA service area, communities rely on local surface water, groundwater, or a combination. The Massachusetts Department of Environmental Protection (MassDEP) oversees approximately 1,600 public water systems.
Massachusetts has been at the forefront of PFAS regulation, driven in large part by one of the worst military PFAS contamination sites in the entire country: Joint Base Cape Cod.
Joint Base Cape Cod (formerly Otis Air National Guard Base) is ground zero for military PFAS contamination in Massachusetts and one of the most contaminated sites nationally. Decades of firefighting training with AFFF created massive PFAS plumes in the sandy, permeable soils of Cape Cod, where groundwater is the sole drinking water source. PFAS concentrations in some monitoring wells have exceeded 40,000 ppt – thousands of times above health advisory levels. The contamination has affected public water supply wells in Bourne, Falmouth, Mashpee, and Sandwich, and has spread across miles of the Cape Cod aquifer system.
Beyond Cape Cod, PFAS has been detected at Westover Air Reserve Base in Chicopee, Barnes Air National Guard Base in Westfield, and at numerous municipal airports and fire training facilities across the state. Industrial sources – including facilities in the Merrimack Valley that manufactured PFAS-containing products – have also contributed to contamination.
Massachusetts adopted one of the most aggressive PFAS standards in the nation: a maximum contaminant level of 20 ppt for the sum of six PFAS compounds (PFOS, PFOA, PFHxS, PFNA, PFDA, and PFHpA). This combined standard means that even if no single compound exceeds 20 ppt, the sum of all six must remain below that threshold. MassDEP has required all public water systems to test for PFAS, and dozens of systems have had to install treatment or take contaminated sources offline.
Massachusetts has some of the strictest PFAS regulations in the country, rivaling Michigan, New Jersey, and Vermont. The state's 20 ppt combined MCL is more protective than the federal standards and more stringent than most state-level limits. This aggressive posture reflects both the severity of the Cape Cod contamination and the state's historically strong environmental regulatory culture.
Joint Base Cape Cod's contamination is among the top military PFAS sites nationally. The EPA has listed the base on the National Priorities List (Superfund) since 1989, and the PFAS contamination is being addressed as part of a broader cleanup that also includes solvents, fuels, and other military contaminants. The cleanup has been ongoing for over three decades, and PFAS remediation will add years and hundreds of millions of dollars to the effort.
The MWRA's reservoir system, by contrast, is one of the cleanest large municipal supplies in the country. Quabbin Reservoir, built in the 1930s by flooding four towns in the Swift River Valley, provides over 400 billion gallons of storage in a protected watershed with minimal development. PFAS detections in the MWRA supply have been at or below detection limits – a stark contrast to the groundwater-dependent systems on Cape Cod.
Water quality in Massachusetts depends heavily on whether you are in the MWRA service area, on Cape Cod, or in a community with its own local water source.
1. Check your specific location at the homepage. We show PFAS data and other contaminant results by ZIP code. 2. Cape Cod residents should pay close attention to their water system's PFAS treatment status. Several towns have installed granular activated carbon treatment, but others are still in the design or construction phase. If you are on a private well on Cape Cod, PFAS testing is strongly recommended. 3. Communities near Westover ARB, Barnes ANGB, or other military facilities should verify their system's PFAS monitoring results with MassDEP. 4. Review our water filter guide for point-of-use options. Massachusetts' strict standards mean your utility is required to address PFAS above 20 ppt combined, but if you want additional protection at the tap, certified filters can reduce levels further. Our detailed water report shows trends over time.
Massachusetts has a long history of water infrastructure innovation. Boston's metropolitan water system, which eventually became the MWRA, was one of the first large-scale municipal water projects in the nation. The Cochituate Aqueduct, completed in 1848, was followed by increasingly ambitious reservoir and tunnel projects through the 19th and 20th centuries.
The construction of Quabbin Reservoir in the 1930s required the flooding of four towns – Dana, Enfield, Greenwich, and Prescott – and the relocation of their roughly 2,500 residents. The reservoir, which took seven years to fill, remains one of the largest man-made public water supplies in the country. Its watershed is actively managed by the state Division of Water Supply Protection, with strict limits on development, recreation, and land use.
Joint Base Cape Cod's contamination history dates to the 1940s, when military operations began on what was then Camp Edwards. The base was used for Army training, Air National Guard operations, and Coast Guard aviation. Firefighting training areas, fuel spills, and industrial operations contaminated the underlying sand-and-gravel aquifer – the same aquifer that provides drinking water for the entire Cape. The discovery of widespread contamination in the 1980s led to the Superfund listing, and cleanup has been ongoing since.
The PFAS chapter began coming into focus in the 2010s, when improved analytical methods allowed testing at the parts-per-trillion level. What had been undetectable suddenly became measurable, and the results on Cape Cod were alarming. The Installation Restoration Program at Joint Base Cape Cod has identified multiple PFAS plumes, some extending miles from the source areas. Pump-and-treat systems are operating, but PFAS remediation in a sole-source aquifer is technically challenging and will continue for decades.
Massachusetts' regulatory response has been among the most comprehensive in the nation. Beyond the drinking water MCL, the state has established cleanup standards for PFAS in soil and groundwater, notification requirements for releases, and limits on PFAS in biosolids applied to land. The 2023 PFAS Interagency Task Force report laid out a multi-agency strategy for addressing contamination statewide.
Check your address to see the latest data for your community. In a state where water quality ranges from pristine reservoir water to some of the most PFAS-contaminated groundwater in the country, your specific location makes all the difference.