Suffolk County, Massachusetts: drinking water report. Suffolk County encompasses Boston, Chelsea, Revere, and Winthrop, serving roughly 800,000 residents…
Suffolk County encompasses Boston, Chelsea, Revere, and Winthrop, serving roughly 800,000 residents through the Massachusetts Water Resources Authority (MWRA) system. The MWRA draws primarily from the Quabbin and Wachusett Reservoirs in central Massachusetts, delivering water through one of the nation's oldest urban distribution networks. Boston's aging infrastructure, with pipe sections dating to the 1800s, creates distinct concerns despite high-quality source water.
The MWRA source water consistently meets federal standards, but the delivery system presents challenges characteristic of legacy urban infrastructure. Lead service lines remain throughout Boston and surrounding municipalities, particularly in neighborhoods developed before 1950. The city has documented elevated lead levels in homes with older plumbing, especially during periods of low water use or after service line work. Massachusetts regulations require action when more than 10 percent of targeted samples exceed 15 parts per billion for lead, and Boston has periodically approached or exceeded this threshold in specific sampling rounds.
PFAS contamination has been detected across Massachusetts water systems, though the MWRA reservoirs show lower levels than groundwater-dependent systems elsewhere in the state. The 2023 EPA UCMR5 testing cycle identified PFAS compounds in some Massachusetts utilities at levels that would exceed the newly proposed federal limits of 4 parts per trillion for PFOA and PFOS. Urban and industrial history in Suffolk County creates multiple potential PFAS sources, including former manufacturing sites, firefighting foam use at Logan Airport, and stormwater runoff. The MWRA has invested in treatment upgrades, but residents in buildings with private wells or served by smaller water systems face different risk profiles.
Chlorination byproducts like trihalomethanes (THMs) appear in systems serving dense urban areas where water spends extended time in distribution pipes. Boston's system must balance adequate disinfection against byproduct formation, a challenge amplified by warm weather and older infrastructure that allows longer residence times. Some neighborhoods see seasonal THM spikes that approach or occasionally exceed the 80 parts per billion maximum contaminant level.
Boston-area residents should verify whether their building contains lead service lines or lead solder (common in homes built before 1986) and consider testing if they live in pre-1950 construction. Property owners in Chelsea, Revere, and Winthrop should similarly assess their plumbing age and materials. Check your water to see current contamination data for your specific ZIP code, review our water filter guide for certified filtration options that address lead and PFAS, and access your detailed report for full contaminant breakdowns. For broader context on Massachusetts water quality patterns and regulatory updates, visit our state page.