Water quality by county
in Pennsylvania
EPA sampled public water systems across Pennsylvania for PFAS under its UCMR 5 programme. Of the 67 counties, 26 have a reading above a federal limit and 2 have not been sampled at all — which is not a clean result, only an absence of one. Each county below shows what was found, at what concentration, and at which utility.
| county | Population | Worst result | Compound |
|---|---|---|---|
| Montgomery County | 879,190 | 59× | PFOA · 235 ng/L |
| Lehigh County | 385,655 | 38× | PFOS · 153 ng/L |
| Berks County | 439,117 | 14× | PFOA · 55.8 ng/L |
| Carbon County | 65,743 | 11× | PFOA · 42.5 ng/L |
| Lancaster County | 563,293 | 6.0× | PFOA · 23.8 ng/L |
| Bucks County | 650,131 | 5.8× | PFOS · 23 ng/L |
| Delaware County | 584,882 | 5.6× | PFOA · 22.3 ng/L |
| Allegheny County | 1,231,814 | 4.7× | PFOS · 18.8 ng/L |
| Chester County | 560,745 | 4.4× | PFOA · 17.7 ng/L |
| Schuylkill County | 144,523 | 4.3× | PFOS · 17 ng/L |
| Cumberland County | 275,516 | 4.2× | PFOS · 16.9 ng/L |
| Adams County | 107,914 | 3.5× | PFOS · 14.1 ng/L |
| Dauphin County | 293,029 | 3.2× | PFOS · 12.7 ng/L |
| Lycoming County | 113,236 | 3.0× | PFOS · 12.1 ng/L |
| Beaver County | 165,540 | 2.8× | PFHxS · 28.2 ng/L |
| York County | 471,240 | 2.8× | PFOS · 11.2 ng/L |
| Luzerne County | 331,379 | 2.3× | PFOS · 9.1 ng/L |
| Lackawanna County | 216,859 | 2.0× | PFOA · 8.1 ng/L |
| Philadelphia County | 1,573,916 | 2.0× | PFOA · 8.1 ng/L |
| Columbia County | 66,012 | 2.0× | PFOA · 7.9 ng/L |
| Wyoming County | 25,771 | 1.6× | PFOS · 6.6 ng/L |
| Crawford County | 82,089 | 1.4× | PFOS · 5.7 ng/L |
| Monroe County | 166,523 | 1.4× | PFOA · 5.7 ng/L |
| Centre County | 159,805 | 1.3× | PFOS · 5.1 ng/L |
| Westmoreland County | 350,935 | 1.1× | PFOS · 4.5 ng/L |
| Butler County | 199,341 | 1.1× | PFOA · 4.2 ng/L |
| Armstrong County | 63,679 | under the limit | — |
| Bedford County | 47,643 | under the limit | — |
| Blair County | 120,269 | under the limit | — |
| Bradford County | 59,699 | under the limit | — |
| Cambria County | 130,108 | under the limit | — |
| Cameron County | 4,348 | under the limit | — |
| Clarion County | 36,855 | under the limit | — |
| Clearfield County | 78,132 | under the limit | — |
| Clinton County | 37,865 | under the limit | — |
| Elk County | 30,124 | under the limit | — |
| Erie County | 267,750 | under the limit | — |
| Fayette County | 123,941 | under the limit | — |
| Forest County | 6,601 | under the limit | — |
| Franklin County | 159,285 | under the limit | — |
| Fulton County | 14,452 | not sampled | — |
| Greene County | 33,960 | under the limit | — |
| Huntingdon County | 43,359 | under the limit | — |
| Indiana County | 82,953 | under the limit | — |
| Jefferson County | 43,367 | under the limit | — |
| Juniata County | 23,395 | under the limit | — |
| Lawrence County | 84,233 | under the limit | — |
| Lebanon County | 145,319 | under the limit | — |
| McKean County | 39,478 | under the limit | — |
| Mercer County | 108,140 | under the limit | — |
| Mifflin County | 45,935 | under the limit | — |
| Montour County | 18,115 | under the limit | — |
| Northampton County | 322,989 | under the limit | — |
| Northumberland County | 90,027 | under the limit | — |
| Perry County | 46,816 | under the limit | — |
| Pike County | 62,376 | under the limit | — |
| Potter County | 15,993 | under the limit | — |
| Snyder County | 39,627 | under the limit | — |
| Somerset County | 72,134 | under the limit | — |
| Sullivan County | 5,927 | not sampled | — |
| Susquehanna County | 38,100 | under the limit | — |
| Tioga County | 40,698 | under the limit | — |
| Union County | 42,159 | under the limit | — |
| Venango County | 49,476 | under the limit | — |
| Warren County | 37,373 | under the limit | — |
| Washington County | 210,434 | under the limit | — |
| Wayne County | 51,419 | under the limit | — |