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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
251–275 of 328North Raynham Water District
MA4245002 · 3,902 served
South Deerfield Water Supply District
MA1074001 · 3,800 served
Westminster Department of Public Works
MA2332000 · 3,741 served
Cherry Valley/ Rochdale Water District
MA2151001 · 3,696 served
Ashburnham Water Department
MA2011000 · 3,680 served
Essex Water Dept.
MA3092000 · 3,675 served
Mci Shirley
MA2270001 · 3,500 served
Boylston Water District
MA2039000 · 3,343 served
Nahant Water Dept. (mwra)
MA3196000 · 3,334 served
South Grafton Water District
MA2110001 · 3,262 served
Three Rivers Fire District
MA1227003 · 3,258 served
Belchertown Water District
MA1024000 · 3,253 served
West Brookfield Water Department
MA2323000 · 3,217 served
Leicester Water Supply District
MA2151000 · 3,200 served
Sunderland Water District
MA1289000 · 3,190 served
Hatfield Water Dept
MA1127000 · 3,183 served
West Newbury Water Department
MA3324000 · 3,080 served
Hanscom Family Housing (landings)
MA3157001 · 3,067 served
Wellesley College
MA3317001 · 3,000 served
Siasconset Water Department
MA4197001 · 3,000 served
Mci Bridgewater
MA4042001 · 2,802 served
East Chelmsford Water District
MA3056001 · 2,800 served
Stockbridge Water Dept
MA1283003 · 2,800 served
Wilkinsonville Water District
MA2290014 · 2,773 served
Tewksbury Hospital
MA3295001 · 2,500 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
Quick Links
Data source: Utility data from EPA SDWIS. 328 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-19