Boston MA metro: water quality. Greater Boston benefits from one of the better-protected municipal water sources in the country.
Greater Boston benefits from one of the better-protected municipal water sources in the country. The Massachusetts Water Resources Authority (MWRA) serves Boston, Cambridge, and about 50 other communities from the Quabbin and Wachusett reservoirs in central Massachusetts – a system so clean it earned a filtration waiver from the EPA, meaning only ozonation and UV disinfection are required rather than full conventional filtration. But the 4.9 million person metro extends well beyond MWRA territory. Worcester runs its own system from ten reservoirs. Springfield draws from the Cobble Mountain Reservoir. Smaller communities across the metro operate independent systems with varying source water quality.
What you drink depends entirely on which of these providers your municipality has chosen.
MWRA's reservoir-sourced water has shown very low PFAS detections under UCMR5, consistent with its protected watershed. The deeper concern in this metro sits outside MWRA's service area. Communities on Cape Cod, near Joint Base Cape Cod (formerly Otis Air National Guard Base), have reported some of the highest PFAS levels in New England. Hanscom Air Force Base, northwest of Boston in Bedford, is another documented contamination source.
Massachusetts set a combined PFAS MCL – the sum of six PFAS compounds – at 20 ppt, one of the stricter group standards in the country. The Massachusetts Department of Environmental Protection (MassDEP) has also required public water systems to test for PFAS and report results publicly. According to MassDEP's 2024 PFAS data, 38 community water systems statewide exceeded the 20 ppt threshold, with a concentration of those in communities near military sites and manufacturing facilities.
Our data integrates MassDEP reports, UCMR5 results, and utility-level data to show you how your specific provider performs.
Boston sits in a strong position nationally thanks to MWRA's protected reservoir system. Among northeastern metros, only New York's Catskill-sourced supply is comparably well-shielded. Philadelphia and DC, both drawing from rivers, face higher contamination exposure.
The risk within this metro, though, is uneven. A Cambridge resident on MWRA water has a very different exposure profile than a Springfield resident on Cobble Mountain supply or a Worcester resident on a locally managed reservoir system. Communities that rely on groundwater face the highest PFAS risk, particularly those near military bases or manufacturing sites.
Visit our Massachusetts state page for statewide data.
First, confirm whether you're on MWRA water or a local system. MWRA serves about 2.5 million of the metro's 4.9 million residents; the rest are on independent supplies.
Check your water to see exactly which system serves your address and what it has reported. If you're on MWRA, your PFAS exposure is likely minimal. If you're on a local system – especially one using groundwater – reviewing the data is more urgent. Our water filter guide matches filter technology to your specific contaminant profile. For historical trends and compliance history, pull a detailed report.