Is Boston Tap Water Safe? Boston Water and Sewer Commission (MWRA water)’s EPA Records

City water quality

Is Boston Tap Water Safe? What Boston Water and Sewer Commission (MWRA water)’s EPA Records Show

Boston Water and Sewer Commission (MWRA water), which serves about 675,647 people in Massachusetts, reported no PFAS above reporting limits in the EPA’s UCMR5 monitoring (2023-2025). Non-detect means not found above the EPA’s reporting floor in that round — not that the water was never tested again. Its most recent EPA-record lead 90th-percentile (22.5 ppb) was above the action level — a system-wide statistic, not any single tap. The system has 4 health-based violations on its federal SDWA record.

EPA records (UCMR5 2023-2025 + SDWIS/ECHO)
Boston Water and Sewer Commission (MWRA water)
Action recommended
Population served (SDWIS)675,647
PFOA vs 4 ppt limitnon-detect
PFOS vs 4 ppt limitnon-detect
PFHxS vs 10 ppt limit (under reconsideration)non-detect
PFNA vs 10 ppt limit (under reconsideration)non-detect
GenX (HFPO-DA) vs 10 ppt limit (under reconsideration)non-detect
Lead 90th percentile (latest round)22.5 ppb
SDWA violations on record (health-based)8 (4)
These are the systems’ own EPA UCMR5 monitoring results — “reported above the limit,” not “in violation.” The EPA limit (4 ppt for PFOA and for PFOS) is a running annual average, so a system counts here when the AVERAGE of a full set of results at one of its sampling locations is above the limit — EPA’s own method. That is an occurrence flag, not a compliance finding: real compliance is determined from quarterly samples reported to the state. Enforcement phases in through 2029-2031.
A metro area is usually served by more than one water system — this page covers the area's largest. Suburbs and neighboring towns often have their own systems with their own results; check your exact ZIP for yours.

See the full interactive report for this system — every PFAS analyte, lead and copper rounds, violations, and the filter that handles what was found: open the Boston report → Or check YOUR exact ZIP: check your water by ZIP →

Common questions about Boston water

Is Boston's tap water safe to drink?

The records show lead above a current EPA limit or action level — the details, with dates, are in the sections above. That is a system-level occurrence record, not a verdict on any individual tap. These are system-level records for public water systems, not a reading of any individual home’s tap, and they do not cover private wells. Confirm your own utility’s current Consumer Confidence Report, and test your tap if you’re unsure.

Does Boston have PFAS in its drinking water?

Boston Water and Sewer Commission (MWRA water) reported no PFAS above reporting limits in UCMR5 monitoring.

Who supplies Boston's drinking water?

Boston Water and Sewer Commission (MWRA water) (PWSID MA3035000) serves about 675,647 people, per EPA SDWIS records. A metro area is usually served by more than one water system — this page covers the area’s largest. Suburbs and neighboring towns often have their own systems with their own results; check your exact ZIP for yours.

How do I check my exact address?

Water systems report by system, not by address. Enter your ZIP on the water checker to see the system(s) serving it and what each reported.

Statewide, 26.7% of Massachusetts’s UCMR5-tested systems reported PFOA or PFOS over the EPA limit — see the Massachusetts water page.

See the 100 largest US water systems, water quality by state, and the national PFAS data study.

Sources: EPA UCMR5 occurrence data, Feb 2026 release (~95% complete; final reporting 2026) (2026-06); lead/copper + violations: EPA SDWIS via ECHO; population served: EPA SDWIS via ECHO (system-reported population served). PWSID MA3035000. Public-domain federal/state records; assembly by WaterByTheBook. Built 2026-07-25. Plain-markdown mirror: https://waterbythebook.com/md/boston.md