TTHM (Total Trihalomethanes) violations in Connecticut
23 active public water systems in Connecticut had a TTHM (Total Trihalomethanes) violation in the past three years, 3 of them in the latest quarter of EPA's data. What TTHM (Total Trihalomethanes) is and why it matters.
Systems with a TTHM (Total Trihalomethanes) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Bethel Water Dept Bethel, Danbury · Fairfield County |
9,507 | 6 | 0 | |
|
Apple Rehab Rocky Hill · Hartford County |
238 | 6 | 2 | |
|
Country Manor Pomfret · Windham County |
66 | 3 | 3 | |
|
East Lyme Water & Sewer Commission East Lyme · New London County |
15,245 | 1 | 0 | |
|
Cromwell Fire District Water Department Berlin, Cromwell · Middlesex County |
14,316 | 1 | 0 | |
|
Kensington Fire District Berlin, New Britain, Newington · Hartford County |
7,553 | 4 | 0 | |
|
Berlin Water Control Commission Berlin, Middletown, Newington · Hartford County |
5,128 | 5 | 2 | |
|
Colchester Sewer & Water Commission Colchester · New London County |
4,020 | 4 | 0 | |
|
Ledyard Wpca Ledyard Center Ledyard · New London County |
3,294 | 3 | 1 | |
|
Worthington Fire District Berlin · Hartford County |
2,875 | 3 | 0 | |
|
New Fairfield High/middle School New Fairfield · Fairfield County |
1,400 | 5 | 0 | |
|
Shepaug Middle/high School Washington · Litchfield County |
770 | 2 | 1 | |
|
Head O'meadow Elementary School Newtown · Fairfield County |
506 | 1 | 0 | |
|
Candle Hill Mobile Home Park New Milford · Litchfield County |
233 | 4 | 0 | |
|
Mallard Cove Condominium Assn. East Hampton · Middlesex County |
177 | 7 | 0 | |
|
55 Sugar Street Newtown · Fairfield County |
158 | 5 | 2 | |
|
Cobalt Lodge Healthcare & Rehab Center East Hampton · Middlesex County |
130 | 5 | 0 | |
|
Markham Meadows Campground-Well #2 East Hampton · Middlesex County |
120 | 1 | 0 | |
|
Ridgeview Heights Willington · Tolland County |
96 | 2 | 1 | |
|
Talcott Mountain Science Center #2 Avon · Hartford County |
59 | 6 | 2 | |
|
John Dorr Nature Lab Washington · Litchfield County |
30 | 1 | 0 | |
|
Westside Manor East Hampton · Middlesex County |
30 | 5 | 0 | |
|
St. Thomas More School-The Cove Montville · New London County |
25 | 1 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved TTHM (Total Trihalomethanes), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not TTHM (Total Trihalomethanes) alone.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Connecticut records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.