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 |
|---|---|---|---|---|
|
Kittanning Plumcreek Watr Auth Armstrong County |
600 | 2 | 0 | |
|
Maplewood Jr/sr High School Crawford County |
600 | 5 | 1 | |
|
Moniteau Jr/sr High School Butler County |
600 | 2 | 0 | |
|
Springtown Water Authority Bucks County |
600 | 2 | 1 | |
|
Knoxville Water Department Tioga County |
590 | 4 | 0 | |
|
Meshoppen Borough Water CO Wyoming County |
563 | 3 | 1 | |
|
Palisades Senior High School Bucks County |
562 | 3 | 0 | |
|
Clintonville Boro Wtp Venango County |
557 | 5 | 0 | |
|
Aqua PA Laurel Lakes Luzerne County |
552 | 2 | 0 | |
|
Haines Aaronsburg Mun Auth Centre County |
550 | 2 | 1 | |
|
Paradise MHP Perry County |
550 | 2 | 1 | |
|
Liberty Valley Elem School Montour County |
549 | 2 | 0 | |
|
Crestview Elem Sch Cumberland County |
537 | 1 | 0 | |
|
Quincy Twp Water System Franklin County |
530 | 2 | 0 | |
|
Brecknock Elementary School Lancaster County |
500 | 1 | 0 | |
|
Chadds Ford Elementary School Chester County |
500 | 3 | 0 | |
|
Icmsa Rossiter Indiana County |
500 | 4 | 0 | |
|
Keystone Job Corps Center Luzerne County |
500 | 4 | 1 | |
|
Maplewood Elementary School Crawford County |
500 | 5 | 1 | |
|
Pike County Correctional Facil Pike County |
500 | 6 | 0 | |
|
Rouseville Mun Waterworks Venango County |
500 | 5 | 0 | |
|
Ulster Municipal Authority Bradford County |
500 | 3 | 1 | |
|
Palm City Park Lebanon County |
490 | 9 | 1 | |
|
Brookside Village MHP Columbia County |
475 | 9 | 0 | |
|
ST Petersburg Municipal Water Clarion County |
465 | 7 | 0 | |
|
Lake Arthur Estates Butler County |
460 | 6 | 1 | |
|
Rayburn Twp Joint Muni Auth Armstrong County |
460 | 2 | 0 | |
|
Martic Twp Elem Sch Lancaster County |
456 | 1 | 0 | |
|
Amblebrook Adams County |
450 | 1 | 0 | |
|
Blue Heron Homeowners Assoc Carbon County |
450 | 8 | 0 | |
|
Genesee Twp Water Authority Potter County |
450 | 11 | 1 | |
|
Lake Noxen Elementary School Luzerne County |
450 | 4 | 1 | |
|
Lower Mahanoy Twp Mun Auth Northumberland County |
450 | 4 | 0 | |
|
Moore Elementary School Northampton County |
448 | 2 | 0 | |
|
Three Springs Boro Water CO Huntingdon County |
442 | 3 | 0 | |
|
Longwood Gardens Chester County |
440 | 5 | 0 | |
|
Big Spring Terrace MHP Cumberland County |
439 | 4 | 0 | |
|
Miles Twp Water Auth East Centre County |
425 | 4 | 1 | |
|
Pine Valley Mobile Home Court Union County |
425 | 4 | 0 | |
|
Porter Township Municipal Auth Clinton County |
425 | 2 | 0 | |
|
Red Rock Job Corps Center Sullivan County |
425 | 4 | 0 | |
|
Laceyville Water CO Wyoming County |
415 | 1 | 0 | |
|
Providence Elem Sch Lancaster County |
415 | 1 | 0 | |
|
Lutheran Home at Topton Berks County |
410 | 1 | 0 | |
|
Gretna Springs Lebanon County |
405 | 4 | 0 | |
|
Loganton Boro Water System Clinton County |
402 | 2 | 0 | |
|
Hamlin Water Company Wayne County |
400 | 6 | 0 | |
|
New Drums Elementary School Luzerne County |
400 | 2 | 0 | |
|
Ralston Area Joint Authority Lycoming County |
400 | 7 | 2 | |
|
Sru Middle School Bradford County |
400 | 3 | 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.