TTHM (Total Trihalomethanes) violations in Massachusetts
43 active public water systems in Massachusetts had a TTHM (Total Trihalomethanes) violation in the past three years, 7 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 |
|---|---|---|---|---|
|
Scituate Water Division Scituate · Plymouth County |
19,297 | 6 | 2 | |
|
Plainville Water Department Plainville · Norfolk County |
8,805 | 1 | 0 | |
|
Cohasset Water Dept Cohasset · Norfolk County |
7,555 | 1 | 1 | |
|
Otis Air National Guard Base Falmouth · Barnstable County |
6,000 | 2 | 2 | |
|
Dighton Water District Dighton · Bristol County |
5,280 | 1 | 0 | |
|
Pequot Highlands Salem · Essex County |
900 | 1 | 0 | |
|
Linden Ponds Hingham · Plymouth County |
384 | 3 | 0 | |
|
Salem and Beverly Water Supply Board Beverly · Essex County |
90,330 | 1 | 0 | |
|
Chicopee Water Dept (mwra) Chicopee · Hampden County |
55,560 | 2 | 1 | |
|
Hyannis Water System, Town of Barnstable Barnstable · Barnstable County |
35,000 | 1 | 0 | |
|
Stoughton Water Department Stoughton · Norfolk County |
29,281 | 2 | 0 | |
|
Chelmsford Water District Chelmsford · Middlesex County |
28,750 | 1 | 0 | |
|
Agawam Water Department Agawam · Hampden County |
28,692 | 1 | 0 | |
|
Wakefield Water Dept Wakefield · Middlesex County |
27,090 | 2 | 1 | |
|
Walpole Water Dept Walpole · Norfolk County |
24,070 | 1 | 0 | |
|
Westborough Water Department Westborough · Worcester County |
21,567 | 4 | 0 | |
|
Norton Water Department Norton · Bristol County |
19,161 | 2 | 1 | |
|
Somerset Water Department Somerset · Bristol County |
18,303 | 1 | 0 | |
|
Clinton Water Dept Clinton · Worcester County |
15,428 | 1 | 0 | |
|
South Hadley FD #1 (mwra) South Hadley · Hampshire County |
14,800 | 1 | 0 | |
|
North Adams Water Dept North Adams · Berkshire County |
13,000 | 1 | 0 | |
|
Holbrook Public Works Dept Holbrook · Norfolk County |
11,405 | 2 | 1 | |
|
Raynham Center Water District Raynham · Bristol County |
10,964 | 1 | 0 | |
|
Maynard Dpw, Water Division Maynard · Middlesex County |
10,746 | 3 | 0 | |
|
Wilbraham Water Dept (mwra) Wilbraham · Hampden County |
8,533 | 1 | 0 | |
|
Middleton Water Dept. Middleton · Essex County |
7,291 | 2 | 1 | |
|
Sterling Water Department Sterling · Worcester County |
6,814 | 2 | 0 | |
|
Shirley Water District Shirley · Middlesex County |
4,165 | 4 | 2 | |
|
Westminster Department of Public Works Westminster · Worcester County |
3,889 | 1 | 0 | |
|
Boylston Water District Boylston · Worcester County |
3,343 | 1 | 0 | |
|
Elm Hill Water District Auburn · Worcester County |
2,278 | 2 | 0 | |
|
Aquarion Water Company Ponds of Plymouth Plymouth · Plymouth County |
2,267 | 1 | 0 | |
|
Carver High School and Middle School Carver · Plymouth County |
1,200 | 1 | 0 | |
|
Summer Village Westford · Middlesex County |
1,000 | 2 | 1 | |
|
Chester Water Dept Chester · Hampden County |
750 | 3 | 1 | |
|
Blandford Water Dept Blandford · Hampden County |
442 | 3 | 2 | |
|
Ashfield Water District Ashfield · Franklin County |
400 | 2 | 1 | |
|
Millbury Ind. Park/ Park Hill Village Millbury · Worcester County |
400 | 5 | 0 | |
|
Masters Academy International Stow · Middlesex County |
225 | 4 | 0 | |
|
Leino Park Water District Westminster · Worcester County |
120 | 1 | 0 | |
|
Monroe Water District Monroe · Franklin County |
55 | 3 | 2 | |
|
Foxglove Apartments Harvard · Worcester County |
40 | 1 | 0 | |
|
Lfb USA 92 (rabbit) Charlton · Worcester 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 Massachusetts 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.