TTHM (Total Trihalomethanes) violations in Pennsylvania
535 active public water systems in Pennsylvania had a TTHM (Total Trihalomethanes) violation in the past three years, 39 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 |
|---|---|---|---|---|
|
Village Ctr at Lords Valley Pike County |
400 | 4 | 1 | |
|
ST Clairsville Water Company Bedford County |
392 | 5 | 1 | |
|
Birchwood Trailer Park Monroe County |
389 | 5 | 1 | |
|
Waterford Waterworks Westmoreland County |
389 | 8 | 0 | |
|
Umh Valley Stream Luzerne County |
384 | 4 | 0 | |
|
Hickory Hill Country Village Erie County |
375 | 9 | 0 | |
|
MT Gretna Campmeeting Assn Lebanon County |
375 | 1 | 0 | |
|
Washington Estates II MHC LLC Washington County |
373 | 4 | 0 | |
|
Palisades Middle School Bucks County |
366 | 4 | 0 | |
|
Leraysville Water Company Bradford County |
360 | 4 | 0 | |
|
West Penn Elementary Schuylkill County |
360 | 4 | 0 | |
|
Henderson Township Mun Auth Jefferson County |
354 | 5 | 1 | |
|
Caesars Brookdale on the Lake Monroe County |
350 | 3 | 1 | |
|
Jefferson Twp Water and Sewer Somerset County |
350 | 2 | 0 | |
|
Monroe Elementary School Cumberland County |
350 | 4 | 0 | |
|
Knouse Foods INC Peach Glen Adams County |
340 | 1 | 0 | |
|
Autumn Hills Water Company Crawford County |
338 | 3 | 0 | |
|
New Albany Water Fund Bradford County |
336 | 4 | 1 | |
|
West Buffalo Twp Mun Auth Union County |
333 | 7 | 0 | |
|
Lehigh Valley Dairies Ntnc Montgomery County |
328 | 1 | 0 | |
|
North Star East Mid Sch Somerset County |
325 | 1 | 0 | |
|
Village of Four Seasons Susquehanna County |
325 | 5 | 1 | |
|
N Hopewell Winterstown Elem York County |
322 | 1 | 0 | |
|
Woodland Hills Wayne County |
320 | 6 | 0 | |
|
Aqua PA Water CO Elmbrook Lackawanna County |
300 | 1 | 0 | |
|
Knox Township Munic Authority Jefferson County |
300 | 8 | 0 | |
|
Mignosis Foodtown Monroe County |
300 | 2 | 0 | |
|
Neshaminy Warwick Pres Church Bucks County |
300 | 3 | 0 | |
|
New Meadow Run Fayette County |
300 | 5 | 0 | |
|
Penn 80 Milton Northumberland County |
300 | 9 | 0 | |
|
The Meadows Centre County |
289 | 4 | 0 | |
|
Addison Area Water Auth Somerset County |
284 | 7 | 0 | |
|
Clarendon Acres Water CO Wyoming County |
280 | 7 | 2 | |
|
Halifax Village Dauphin County |
272 | 9 | 0 | |
|
Stony Brook Circle MHP Columbia County |
272 | 1 | 0 | |
|
Columbia CO Christian School Columbia County |
270 | 2 | 0 | |
|
Carson Towers Allegheny County |
266 | 2 | 1 | |
|
Pine Grove Estates Wayne County |
263 | 7 | 0 | |
|
Buckingham Green Center Bucks County |
253 | 3 | 0 | |
|
Aqua PA Shickshinny Lake Luzerne County |
250 | 2 | 0 | |
|
Cogan Valley Mobile Home Park Lycoming County |
250 | 10 | 1 | |
|
Coventry Terrace Chester County |
250 | 3 | 0 | |
|
Leprino Foods Bradford County |
250 | 5 | 0 | |
|
Talen Energy Montour County |
250 | 1 | 0 | |
|
Loysville Youth Dev Ctr Perry County |
249 | 6 | 0 | |
|
Pine Grove Mobile Home Park Mercer County |
244 | 3 | 0 | |
|
East Springfield Elem School Erie County |
240 | 1 | 0 | |
|
Independence Park Beaver County |
225 | 5 | 0 | |
|
Morea Citizens Water Company Schuylkill County |
225 | 1 | 0 | |
|
Penn Valley Village Lancaster County |
225 | 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 Pennsylvania 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.