Boston tap water: lead, PFAS and violations

Supplied by Boston Water and Sewer Commission (water from MWRA) · EPA ID MA3035000 · 675,647 people

By Daryna Klochko · Data checked Oct 13, 2026
Short answer

Boston tap water comes from Boston Water and Sewer Commission, which serves 675,647 people. In Jan – Jun 2026 sampling, the lead 90th percentile was 5.8 ppb, against the 15 ppb action level. EPA-required UCMR 5 testing found no PFAS at reporting levels. EPA lists 1 health-based violation in the last 10 years, the latest in Nov 2020.

Lead · 90th pct 5.8 ppb Action level 15 ppb · Jan – Jun 2026 PFAS · UCMR 5 None detected 29 PFAS tested · Jan 2024 – Oct 2024 Hardness — not reported Not in EPA’s records EPA violations · 10 yrs 1 record 1 health-based · 1 in all since 2020

These numbers describe the water system, not your tap. Lead and copper often come from pipes and fixtures inside a home, so your water can differ. Where a goal (MCLG) is 0, EPA’s goal for that contaminant is zero. Legal limits are set above it.

Is Boston tap water safe to drink?

In the latest results, every contaminant we list with a single federal limit was below that limit or action level. Lead was 5.8 ppb at the 90th percentile, below the 15 ppb action level. EPA’s goal for lead is zero. The previous round (2025) was 22.5 ppb, above the action level. EPA lists 1 health-based violation in the last 10 years, the latest in Nov 2020. EPA’s record shows one health-based violation without a return-to-compliance date: treatment technique under the Lead and Copper Rule (Nov 2020). See how US tap water compares nationally.

What’s in Boston tap water

This page uses EPA records only: lead from SDWIS, PFAS and lithium from UCMR 5. Boston Water and Sewer Commission’s yearly water quality report (Consumer Confidence Report) lists more, and EPA explains how to find it.

ContaminantResultLimitSampledSource
LeadComes mostly from home plumbing, not from the source water. 5.8 ppb 90th percentile reported to EPA; previous round (2025): 22.5 ppb 15 ppbAction level · goal 0Drops to 10 ppb on Nov 1, 2027 (Lead and Copper Rule Improvements). Jan – Jun 2026 EPA SDWIS record, MA3035000
PFOA and PFOS (PFAS)Two “forever chemicals” with a federal limit. Not detected 4 samples at 1 entry point; none at or above the reporting level (4 ppt) 4.0 ppt eachLegal limit (MCL) · goal 0Utilities must comply from 2029; EPA proposed 2031 in May 2026. Jan 2024 – Oct 2024 EPA UCMR 5 final occurrence data (Aug 2026 release)

ppb = parts per billion (µg/L), ppt = parts per trillion (ng/L). The bar shows the result against the limit (black line). Limits: EPA drinking water regulations, PFAS rule, Lead and Copper Rule Improvements. “Not detected” means below the lab’s reporting level, not zero.

EPA violations

EPA’s SDWIS database lists 1 violation record for Boston Water and Sewer Commission since 2020, 1 of them health-based. 1 has no return-to-compliance date on EPA’s record.

Nov 2020 · Treatment technique Lead and Copper Rule Health-based No return-to-compliance date

Shown: health-based violations and everything from the last 10 years. Source: EPA SDWIS record, MA3035000, retrieved Oct 13, 2026.

How hard is Boston water?

Hardness is not in EPA’s records. Boston Water and Sewer Commission’s yearly water quality report is the place to look. Hardness has no federal health limit. A test kit or a lab test measures it at your tap (see how to test water hardness).

What to do with these numbers

Only what the data above points to.

Lead · 5.8 ppb

Lead comes from home plumbing

EPA’s goal for lead is zero. Older faucets, lead solder and lead service lines can add lead at your tap. A filter certified to NSF/ANSI 53 for lead reduces it.

Certified to reduce lead. Lead is not necessarily in your water.

All filters compared →
Your tap, not the system

Test your own water

Boston Water and Sewer Commission’s numbers come from its own sampling sites. A certified lab test of your faucet shows lead and copper from your plumbing. How to test your own tap for lead, starting with your water utility.

All water tests compared →

Questions people ask

Does Boston tap water have lead?
In Jan – Jun 2026 sampling, Boston Water and Sewer Commission’s lead 90th percentile was 5.8 ppb (90th percentile reported to EPA; previous round (2025): 22.5 ppb). The federal action level is 15 ppb, and EPA’s goal is zero. Lead usually enters water from home plumbing, so only a test of your own tap shows your level.
Does Boston tap water have PFAS?
In EPA’s UCMR 5 testing (Jan 2024 – Oct 2024), none of 29 PFAS were found at or above reporting levels at 1 entry point of Boston Water and Sewer Commission’s system. The federal limit for PFOA and PFOS is 4.0 ppt each. Utilities must comply from 2029. On May 18, 2026 EPA proposed letting systems ask for two more years, to 2031, and dropping the 2024 limits for PFHxS, PFNA, HFPO-DA and PFAS mixtures (the Hazard Index).
Has Boston Water and Sewer Commission had EPA violations?
EPA’s SDWIS database lists 1 violation record for Boston Water and Sewer Commission since 2020, 1 of them health-based. 1 has no return-to-compliance date on EPA’s record. EPA lists 1 health-based violation in the last 10 years, the latest in Nov 2020.
Who supplies water in Boston?
Boston Water and Sewer Commission (water from MWRA) (EPA ID MA3035000), a community water system serving 675,647 people through 88,895 connections. Main source: purchased surface water.

Sources and nearby

How to find Boston Water and Sewer Commission’s water quality reportepa.gov EPA record for Boston Water and Sewer Commission (MA3035000)echo.epa.gov EPA UCMR 5 data (PFAS and lithium)epa.gov Massachusetts water quality by cityMA Providence tap waterRINew Haven tap waterCTNew York tap waterNY How we researchMethod