Massachusetts Water Report Card: Worst Water Systems
The most contaminated public water systems in Massachusetts, ranked by PFAS levels, lead, and EPA violations from official EPA data.
Quick Answer
Raynham Center Water District has the highest PFAS in Massachusetts at 92 ppt (23x the EPA limit). Mwra has the highest lead at 10.8 ppb. The tables below rank the worst systems in each category so you can see how your water compares.
Highest PFAS Levels in Massachusetts
Public water systems in Massachusetts with the highest peak PFAS ("forever chemical") reading in EPA UCMR5 testing (2023-2025). The EPA enforceable limit for PFOA and PFOS is 4 ppt.
| # | Water System | Location | Peak PFAS (ppt) | Compounds | vs 4 ppt limit |
|---|---|---|---|---|---|
| 1 | Raynham Center Water District | – | 92 | 6 | 23x |
| 2 | Hatfield Water Dept | – | 60.8 | 4 | 15x |
| 3 | Yarmouth Water Department | West Yarmouth · 38,900 served | 59.4 | 4 | 15x |
| 4 | Dartmouth Water Division | – | 50.6 | 6 | 13x |
| 5 | Duxbury Water Department | – | 46.6 | 8 | 12x |
| 6 | Natick Water Department | – | 37.3 | 5 | 9x |
| 7 | Abington/Rockland Joint Wtr. Works | – | 32 | 6 | 8x |
| 8 | Hyannis Water System, Town Of Barnstable | – | 29.8 | 3 | 7x |
| 9 | Sharon Water Dept | – | 29 | 6 | 7x |
| 10 | Acton Water Supply District | – | 20.6 | 6 | 5x |
| 11 | Ipswich Dpu Water Dept | – | 20.6 | 6 | 5x |
| 12 | Ayer Dpw Water Division | – | 19.9 | 3 | 5x |
Highest Lead Levels in Massachusetts
Community water systems in Massachusetts with the highest 90th-percentile lead result under the EPA Lead and Copper Rule. The EPA action level is 15 ppb; there is no safe level of lead for children.
| # | Water System | Location | Lead 90th-pctile (ppb) | vs 15 ppb |
|---|---|---|---|---|
| 1 | Mwra | Chelsea · 2,660,000 served | 10.8 | within |
| 2 | Onset Fire Districtwater Dept. | Onset · 5,392 served | 10 | within |
| 3 | Tisbury Water Works | Tisbury · 6,082 served | 7.2 | within |
| 4 | Yarmouth Water Department | West Yarmouth · 38,900 served | 5 | within |
| 5 | Taunton Water Division | Taunton · 62,165 served | 4 | within |
| 6 | West Bridgewater Water Dept | West Bridgewater · 7,709 served | 4 | within |
| 7 | Wrentham Water Division | Wrentham · 12,190 served | 4 | within |
| 8 | Wareham Fire District | Parkwood Beach · 21,418 served | 4 | within |
| 9 | Walpole Water Dept | Walpole · 24,070 served | 3 | within |
| 10 | Weymouth Water Department | Weymouth · 57,613 served | 3 | within |
| 11 | Whitman Water System | Whitman · 14,837 served | 2 | within |
| 12 | Southfield Redevelopement Authority | Weymouth · 1,800 served | 0 | within |
Most EPA Violations in Massachusetts
Community water systems in Massachusetts with the most health-based EPA Safe Drinking Water Act violations on record. A health-based violation means a contaminant exceeded its federal limit or required treatment was not applied.
| # | Water System | Location | Health-based violations |
|---|---|---|---|
| 1 | Wareham Fire District | Parkwood Beach · 21,418 served | 1 |
| 2 | Walpole Water Dept | Walpole · 24,070 served | 1 |
| 3 | Tisbury Water Works | Tisbury · 6,082 served | 1 |
| 4 | Yarmouth Water Department | West Yarmouth · 38,900 served | 1 |
| 5 | Weymouth Water Department | Weymouth · 57,613 served | 1 |
| 6 | Onset Fire Districtwater Dept. | Onset · 5,392 served | 1 |
How This Report Card Is Built
PFAS rankings use EPA UCMR5 monitoring (2023-2025), showing each system's peak detection above the 4 ppt EPA limit. Lead rankings use the EPA Lead and Copper Rule 90th-percentile tap results. Violation counts come from the EPA Safe Drinking Water Information System (SDWIS) and count health-based violations. Lead and violation lists are limited to community water systems serving 1,000 or more people. Figures are the most severe on record and do not necessarily reflect current treated water.
Frequently Asked Questions
What is the most PFAS-contaminated water system in Massachusetts?
In EPA UCMR5 testing (2023-2025), Raynham Center Water District had the highest recorded PFAS level in Massachusetts at 92 ppt - about 23x the EPA's 4 ppt limit for PFOA and PFOS.
Which Massachusetts water system has the highest lead levels?
Mwra in Chelsea had the highest 90th-percentile lead result in Massachusetts under the EPA Lead and Copper Rule at 10.8 ppb (within the 15 ppb action level).
Which Massachusetts water system has the most EPA violations?
Wareham Fire District in Parkwood Beach has the most health-based EPA Safe Drinking Water Act violations on record in Massachusetts, with 1 violations.
Where does the Massachusetts water report card data come from?
PFAS figures come from EPA UCMR5 monitoring (2023-2025), lead from the EPA Lead and Copper Rule 90th-percentile tap results, and violations from EPA SDWIS health-based violation records. Figures are the most severe on record and do not necessarily reflect current treated water. Check your exact address at knowyourexposure.com.
What Massachusetts Residents Should Do
- Look up your exact address at knowyourexposure.com for your system's data
- See the full Massachusetts water quality overview
- If your system is listed, a certified filter (reverse osmosis for PFAS, NSF-53 for lead) reduces exposure at the tap. See the best water filters.