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Massachusetts Water Quality
328
Utilities in database
10.0M
Residents served
18%
On private wells
3
Key contaminants tracked
Drinking Water in Massachusetts
Massachusetts has 328 community water systems serving approximately 10.0 million residents. Primary water sources include surface water. The most commonly reported contaminants include lead, disinfection byproducts, nitrates. 18% of Massachusetts residents rely on private wells. DEP holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Massachusetts
51–75 of 328Braintree Water and Sewer Dept.
MA4040000 · 39,143 served
Yarmouth Water Department
MA4351000 · 38,900 served
Shrewsbury Water Department
MA2271000 · 38,325 served
Chelsea Water Dept. (mwra)
MA3057000 · 38,319 served
Holyoke Water Works
MA1137000 · 37,838 served
Gloucester Public Utility Division
MA3107000 · 37,440 served
Natick Water and Sewer Division
MA3198000 · 37,006 served
Mashpee Water District
MA4172039 · 36,922 served
Andover Water Dept
MA3009000 · 36,569 served
Watertown Water Dept. (mwra)
MA3314000 · 35,329 served
Brewster Water Department
MA4041000 · 35,000 served
Hyannis Water System, Town of Barnstable
MA4020004 · 35,000 served
Randolph Water Department
MA4244000 · 34,362 served
Lexington Water Dept. (mwra)
MA3155000 · 34,074 served
Marshfield Water Department
MA4171000 · 34,000 served
Abington/rockland Joint Wtr. Works
MA4001000 · 33,647 served
Franklin Water Department
MA2101000 · 33,399 served
Needham Water Dept
MA3199000 · 33,130 served
Tewksbury Water Department
MA3295000 · 31,342 served
North Andover Water Dept
MA3210000 · 30,915 served
Milford Water Department
MA2185000 · 30,379 served
Chatham Water Department
MA4055000 · 30,000 served
Norwood Water Dept. (mwra)
MA4220000 · 29,909 served
Mattapoisett River Valley W.d.
MA4173001 · 29,600 served
Northampton Water Division
MA1214000 · 29,571 served
Key Contaminant Concerns in Massachusetts
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always from human activity — nitrate interferes with the blood's ability to carry oxygen. The United States produces over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Massachusetts Water FAQs
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Data source: Utility data from EPA SDWIS. 328 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-19