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Connecticut Water Quality
121
Utilities in database
2.7M
Residents served
22%
On private wells
2
Key contaminants tracked
Drinking Water in Connecticut
Connecticut has 121 community water systems serving approximately 2.7 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead. 22% of Connecticut residents rely on private wells. DPH holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Connecticut
1–25 of 121Regional Water Authority
CT0930011 · 418,900 served
Metropolitan District Commission
CT0640011 · 390,887 served
Aquarion-eastern Fairfield County
CT0150011 · 351,756 served
Aquarion-stamford
CT1350011 · 119,214 served
Waterbury Water Department
CT1510011 · 107,271 served
Ctwc - Northern Reg-western System
CT0473011 · 101,313 served
New Britain Water Department
CT0890011 · 73,534 served
Danbury Water Department
CT0340011 · 62,055 served
Meriden Water Division
CT0800011 · 58,441 served
Aquarion-greenwich
CT0570011 · 53,297 served
Bristol Water Department
CT0170011 · 52,079 served
Manchester Water Department
CT0770021 · 51,198 served
Southington Water Department
CT1310011 · 43,069 served
South Norwalk Electric & Water
CT1030021 · 42,000 served
Middletown Water Department
CT0830011 · 41,019 served
Norwalk First Taxing District
CT1030011 · 40,256 served
Torrington Water Company
CT1430011 · 37,915 served
Wallingford Water Department
CT1480011 · 37,267 served
Norwich Public Utilities
CT1040011 · 36,163 served
Ctwc - Shoreline Region-guilford System
CT0608011 · 33,975 served
Groton Utilities
CT0590011 · 30,200 served
New London Dept. of Public Utilities
CT0950011 · 27,620 served
University of Connecticut - Main Campus
CT0780021 · 27,199 served
Ctwc - Naugatuck Region-central System
CT0880011 · 22,735 served
Windham Water Works
CT1630011 · 21,214 served
Key Contaminant Concerns in Connecticut
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.
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.
Connecticut Water FAQs
Quick Links
Data source: Utility data from EPA SDWIS. 121 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22