TTHM (Total Trihalomethanes) violations in New York
217 active public water systems in New York had a TTHM (Total Trihalomethanes) violation in the past three years, 1 of them still unresolved. What TTHM (Total Trihalomethanes) is and why it matters.
Health effects: Long-term exposure is associated with increased bladder cancer risk. Some studies link high TTHM exposure to adverse reproductive outcomes. Bromodichloromethane is classified as a possible human carcinogen.
Systems with a TTHM (Total Trihalomethanes) violation
Unresolved first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Chelsea Cove Homes Beekman (t) · Dutchess County |
1,450 | 2 | 1 | |
|
Veolia Water New York, Inc. Rd-1 Ardsley (v), Bronxville (v), Dobbs Ferry (v) and 6 more · Westchester County |
146,732 | 1 | 0 | |
|
Veolia Water New York, Inc. Rd-2 Port Chester (v), Rye (t), Rye Brook (v) · Westchester County |
57,301 | 1 | 0 | |
|
Clifton Park Water Authority Clifton Park (t) · Saratoga County |
35,000 | 6 | 1 | |
|
Brockport Village Brockport (v) · Monroe County |
25,918 | 2 | 1 | |
|
Grand Island Town Water Dept. Grand Island (t) · Erie County |
19,500 | 4 | 0 | |
|
Dewitt Wds South De Witt (t) · Onondaga County |
16,200 | 1 | 0 | |
|
Dewitt Wds North De Witt (t) · Onondaga County |
13,600 | 1 | 0 | |
|
Canandaigua-Farmington Consolidated W.d. Farmington (t) · Ontario County |
13,000 | 1 | 0 | |
|
Lcwsa Consolidated Water District Livonia (v) · Livingston County |
9,892 | 1 | 0 | |
|
Colonie Village Colonie (v) · Albany County |
8,030 | 1 | 0 | |
|
Sea Breeze WD Irondequoit (t) · Monroe County |
7,800 | 3 | 0 | |
|
Canandaigua Town Cons. WD Canandaigua (t) · Ontario County |
6,800 | 2 | 0 | |
|
Cambria Water District Cambria (t) · Niagara County |
5,839 | 2 | 0 | |
|
Tioga Downs Tioga (t) · Tioga County |
5,750 | 1 | 0 | |
|
Waverly Village Barton (t) · Tioga County |
4,830 | 1 | 0 | |
|
Glasco Water District Saugerties (t) · Ulster County |
4,071 | 2 | 0 | |
|
Asp Red House Water Supply Red House (t) · Cattaraugus County |
4,030 | 1 | 0 | |
|
Asp Barton & Weller Trail Coldspring (t) · Cattaraugus County |
4,025 | 1 | 0 | |
|
Highland Water District Lloyd (t) · Ulster County |
4,000 | 2 | 0 | |
|
Alfred State College Alfred (v) · Allegany County |
3,600 | 4 | 0 | |
|
North Chautauqua County Water District Brocton (v) · Chautauqua County |
3,100 | 2 | 0 | |
|
Red-Rochester Dws Rochester (c) · Monroe County |
3,034 | 2 | 0 | |
|
Frankfort (v) Water Works Frankfort (v) · Herkimer County |
2,995 | 2 | 1 | |
|
Alfred University Alfred (v) · Allegany County |
2,800 | 4 | 0 | |
|
Victor Village Victor (v) · Ontario County |
2,443 | 2 | 1 | |
|
Canajoharie (v) Water Works Canajoharie (v) · Montgomery County |
2,300 | 2 | 1 | |
|
Clyde Village Clyde (v) · Wayne County |
2,269 | 2 | 1 | |
|
Red-Rochester Iws Greece (t), Rochester (c) · Monroe County |
2,185 | 3 | 0 | |
|
Holley Village Holley (v) · Orleans County |
2,150 | 2 | 0 | |
|
Lake George Village Lake George (v) · Warren County |
1,800 | 3 | 1 | |
|
Greenfield Resort Wawarsing (t) · Ulster County |
1,750 | 5 | 0 | |
|
Manchester Village Manchester (v) · Ontario County |
1,709 | 2 | 1 | |
|
Stillwater Village (scwa) Stillwater (v) · Saratoga County |
1,600 | 3 | 1 | |
|
Fort Edward WD #1 (qby/hf) Fort Edward(v) · Washington County |
1,500 | 2 | 0 | |
|
Groveland Correctional Facility Groveland (t) · Livingston County |
1,500 | 1 | 0 | |
|
Sodus Point Village Sodus Point (v) · Wayne County |
1,500 | 3 | 1 | |
|
Philmont Village Philmont (v) · Columbia County |
1,483 | 5 | 0 | |
|
Sandy Creek/lacona Joint Waterworks Lacona (v), Sandy Creek (v) · Oswego County |
1,469 | 3 | 0 | |
|
Milo Town Csa Milo (t) · Yates County |
1,416 | 1 | 0 | |
|
Shortsville Village Shortsville (v) · Ontario County |
1,320 | 3 | 1 | |
|
East Brutus Consolidated Water Districts Brutus (t) · Cayuga County |
1,287 | 2 | 0 | |
|
Naples Consolidated Naples (v) · Ontario County |
1,250 | 4 | 2 | |
|
Wilson Village Wilson (v) · Niagara County |
1,213 | 2 | 1 | |
|
Wallkill/shawangunk Correction Shawangunk (t) · Ulster County |
1,200 | 1 | 0 | |
|
Cattaraugus Village Cattaraugus (v) · Cattaraugus County |
1,185 | 1 | 0 | |
|
East Corning Consolidated District Corning (c) · Steuben County |
1,150 | 2 | 1 | |
|
Unadilla Village Unadilla (v) · Otsego County |
1,128 | 5 | 0 | |
|
Greenville Water District NO 1 Greenville (t) · Greene County |
1,100 | 3 | 1 | |
|
Portville Village Portville (v) · Cattaraugus County |
1,040 | 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 New York 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. Retrieved from ECHO on Oct 11, 2026.