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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
26–50 of 328Medford Water Dept. (mwra)
MA3176000 · 61,700 served
Weymouth Water Department
MA4336000 · 57,613 served
Upper Cape Regional Water Cooperative
MA4261024 · 56,250 served
Chicopee Water Dept (mwra)
MA1061000 · 55,560 served
Peabody Water Dept.
MA3229000 · 54,481 served
Methuen Water Dept
MA3181000 · 53,059 served
Centerville Osterville Marstons Mills Wd
MA4020002 · 50,000 served
Everett Water Dept. (mwra)
MA3093000 · 49,075 served
Beverly Water Dept
MA3030000 · 47,461 served
Plymouth Water Department
MA4239000 · 46,799 served
Attleboro Water Dept
MA4016000 · 46,654 served
Arlington Water Dept. (mwra)
MA3010000 · 46,308 served
Randolph/holbrook Joint Water Board
MA4244001 · 45,767 served
Weir River Water System
MA4131000 · 45,339 served
Salem Water Department
MA3258000 · 44,480 served
Pittsfield Dpu Water Dept
MA1236000 · 43,927 served
Billerica Water Works
MA3031000 · 42,119 served
Fitchburg Dpw Division of Water Supply
MA2097000 · 41,946 served
Marlborough Dpw Water Div. (mwra)
MA2170000 · 41,799 served
Leominster Water Division
MA2153000 · 41,683 served
Dedham Westwood Water Dist.
MA3073000 · 41,630 served
Westfield Dpwwater Division
MA1329000 · 41,094 served
Woburn Water Dept.
MA3347000 · 40,876 served
Amherst Dpw Water Division
MA1008000 · 39,263 served
Harwich Water Department
MA4126000 · 39,144 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