Pennsylvania PFAS results from EPA's final data
Report published Nov 14, 2026 · EPA UCMR 5 final data file of Oct 15, 2026 (samples collected 2023–2025) · Method · National results →
85 Pennsylvania water systems serving 4.2 million people had PFAS above a 2024 federal limit in EPA's final round of nationwide PFAS testing: 24% of the 360 Pennsylvania systems tested, compared with 11% nationally.
Highest PFOA or PFOS averages in Pennsylvania
- Emmaus Borough Public Water Emmaus · PFOS127 ppt
- Pennsylvania American Water – Audubon Lower Providence · PFOS54.1 ppt
- Caernarvon Township Authority Caernarvon · PFOA51.8 ppt
- Palmerton Municipal Authority Palmerton · PFOA39.8 ppt
- Northampton Bucks County Municipal Authority Northampton · PFOS22.1 ppt
- Buckingham Township Cold Spring Water System Buckingham · PFOA20.2 ppt
- Aqua Pennsylvania Hatboro Horsham · PFOS19.1 ppt
- Horsham Water&sewer Authority Horsham · PFOS16.9 ppt
- Collegeville Trappe Joint PWD Skippack · PFOA15.9 ppt
- Pennsylvania American Water – Penn District Reading · PFOS15.4 ppt
- Upper Southampton Municipal Authority Northampton · PFOS14.9 ppt
- City of Lancaster Lancaster · PFOA14.7 ppt
- Telford Borough Authority Telford · PFOA14.4 ppt
- Ashland Area Water Authority Butler · PFOS14.1 ppt
- Ambler Borough Water Dept Ambler · PFOA14.1 ppt
Chart data as a table
| System | ppt |
|---|---|
| Emmaus Borough Public Water · Emmaus · PFOS | 127 |
| Pennsylvania American Water – Audubon · Lower Providence · PFOS | 54.1 |
| Caernarvon Township Authority · Caernarvon · PFOA | 51.8 |
| Palmerton Municipal Authority · Palmerton · PFOA | 39.8 |
| Northampton Bucks County Municipal Authority · Northampton · PFOS | 22.1 |
| Buckingham Township Cold Spring Water System · Buckingham · PFOA | 20.2 |
| Aqua Pennsylvania Hatboro · Horsham · PFOS | 19.1 |
| Horsham Water&sewer Authority · Horsham · PFOS | 16.9 |
| Collegeville Trappe Joint PWD · Skippack · PFOA | 15.9 |
| Pennsylvania American Water – Penn District · Reading · PFOS | 15.4 |
| Upper Southampton Municipal Authority · Northampton · PFOS | 14.9 |
| City of Lancaster · Lancaster · PFOA | 14.7 |
| Telford Borough Authority · Telford · PFOA | 14.4 |
| Ashland Area Water Authority · Butler · PFOS | 14.1 |
| Ambler Borough Water Dept · Ambler · PFOA | 14.1 |
Largest systems above a limit
| # | System | People served |
|---|---|---|
| 1 | Philadelphia Water Department Philadelphia Above: PFOA, PFOS | 1.6 million |
| 2 | Aqua Pennsylvania Main System Northampton Above: PFOA, PFOS | 822,600 |
| 3 | Pennsylvania American Water – Lake Scranton Scranton Above: PFOA, PFOS | 137,142 |
| 4 | City of Lancaster Lancaster Above: PFOA | 120,000 |
| 5 | Pennsylvania American Water – West Dickinson Above: PFOS | 105,127 |
| 6 | Reading Area Water Authority Reading Above: PFOA | 95,100 |
| 7 | North Penn Water Authority Bedminster Above: PFOA | 91,941 |
| 8 | North Wales Water Authority North Wales Above: PFOA, PFOS | 72,496 |
| 9 | Aqua Pennsylvania Bensalem Bensalem Above: PFOA, PFOS | 59,001 |
| 10 | BCWSA Main Lower South Warrington Above: PFOA | 52,621 |
All 85 Pennsylvania systems above a limit
Every Pennsylvania community water system whose UCMR 5 results averaged above a 2024 federal PFAS limit, largest first. Systems that were not tested are not listed: not tested is not the same as not detected.
Full list: 85 systems, largest first
| System | People served |
|---|---|
| Philadelphia Water Department Philadelphia Above: PFOA, PFOS | 1.6 million |
| Aqua Pennsylvania Main System Northampton Above: PFOA, PFOS | 822,600 |
| Pennsylvania American Water – Lake Scranton Scranton Above: PFOA, PFOS | 137,142 |
| City of Lancaster Lancaster Above: PFOA | 120,000 |
| Pennsylvania American Water – West Dickinson Above: PFOS | 105,127 |
| Reading Area Water Authority Reading Above: PFOA | 95,100 |
| North Penn Water Authority Bedminster Above: PFOA | 91,941 |
| North Wales Water Authority North Wales Above: PFOA, PFOS | 72,496 |
| Aqua Pennsylvania Bensalem Bensalem Above: PFOA, PFOS | 59,001 |
| BCWSA Main Lower South Warrington Above: PFOA | 52,621 |
| Pennsylvania American Water – Royersford Richmond Above: PFOA, PFOS | 49,508 |
| Aqua Pennsylvania West Chester West Vincent Above: PFOA | 48,600 |
| Lehigh County Authority – Wlsa Central Division Weisenberg Above: PFOA | 47,693 |
| Veolia Mechanicsburg Fairview Above: PFOS | 45,013 |
| Newtown Artesian Water Company Upper Makefield Above: PFOA, PFOS | 38,500 |
| Moon Township Municipal Authority Moon Above: PFOS | 38,000 |
| Northampton Bucks County Municipal Authority Northampton Above: PFOA, PFOS | 36,750 |
| Aqua Pennsylvania Uwchlan Honey Brook Above: PFOA, PFOS | 35,518 |
| Pennsylvania American Water – Yardley Upper Makefield Above: PFOA, PFOS | 33,171 |
| Pennsylvania American Water – Penn District Reading Above: PFOA, PFOS | 28,508 |
| Carlisle Water Treatment Plant North Middleton Above: PFOS | 26,000 |
| Horsham Water&sewer Authority Horsham Above: PFOA, PFOS | 26,000 |
| Pennsylvania American Water – Glen Alsace Division Robeson Above: PFOA, PFOS | 24,951 |
| Ephrata Area Joint Authority Ephrata Above: PFOA | 24,500 |
| Muhlenberg Township Municipal Authority Muhlenberg Above: PFOA, PFOS | 22,400 |
| Dover Township Water System Dover Above: PFOA, PFOS | 21,097 |
| East Hempfield Water Authority East Hempfield Above: PFOA, PFOS | 20,988 |
| Ambler Borough Water Dept Ambler Above: PFOA, PFOS, Hazard Index | 20,000 |
| Elizabethtown Area Water Mount Joy Above: PFOS | 19,000 |
| Pawc Pocono District Coolbaugh Above: PFOA, PFOS | 17,860 |
| Upper Southampton Municipal Authority Northampton Above: PFOA, PFOS | 16,000 |
| Pennsylvania American Water – Berwick Salem Above: PFOA | 15,282 |
| Perkasie Regional Authority Bedminster Above: PFOA, PFOS | 15,000 |
| Warwick Township Water & Sewer Authority Warwick Above: PFOA, PFOS | 14,699 |
| Emmaus Borough Public Water Emmaus Above: PFOA, PFOS, PFHxS, PFNA, Hazard Index | 14,000 |
| Whitehall Township Authority Whitehall Above: PFOA, PFOS | 13,063 |
| Aqua Pennsylvania Hatboro Horsham Above: PFOA, PFOS | 12,901 |
| Quakertown Borough Water System Quakertown Above: PFOA, PFOS | 12,800 |
| Gettysburg Municipal Authority Cumberland Above: PFOA, PFOS | 12,425 |
| Aqua Pennsylvania Superior Main System New Hanover Above: PFOA, PFOS | 11,400 |
| West Manchester Township Authority West Manchester Above: PFOS | 9,960 |
| Veolia Middletown Londonderry Above: PFOA, PFOS | 9,600 |
| Dillsburg Area Authority Franklin Above: PFOS | 8,962 |
| Aqua Pennsylvania Friendship West Caln Above: PFOA, PFOS | 8,800 |
| Doylestown Borough Water Dept Doylestown Above: PFOA, PFOS | 8,700 |
| Dtma Main System Doylestown Above: PFOA, PFOS | 8,655 |
| New Holland Borough Water System New Holland Above: PFOA, PFOS | 8,490 |
| Collegeville Trappe Joint PWD Skippack Above: PFOA, PFOS | 8,470 |
| North Middleton Water Authority North Middleton Above: PFOS | 8,455 |
| Pennsylvania American Water – Audubon Lower Providence Above: PFOA, PFOS | 8,200 |
| Aqua Pennsylvania Spring Run West Caln Above: PFOA | 8,151 |
| Millersville Univ Water System Manor Above: PFOA, PFOS | 7,950 |
| Veolia Water Bethel Bethel Above: PFOA | 7,809 |
| Upper Leacock Township Water System Upper Leacock Above: PFOA, PFOS | 7,734 |
| Telford Borough Authority Telford Above: PFOA, PFOS | 7,700 |
| Veolia Water PA Dallas Dallas Above: PFOS | 7,563 |
| Littlestown Borough Water System Littlestown Above: PFOA, PFOS | 7,300 |
| Palmerton Municipal Authority Palmerton Above: PFOA, PFOS, PFNA, Hazard Index | 7,000 |
| Richland Township Water Authority Milford Above: PFOA, PFOS | 6,800 |
| East Cocalico Township Authority West Cocalico Above: PFOS | 6,735 |
| Manheim Area Water & Sewer Aut Rapho Above: PFOA, PFOS | 6,701 |
| Veolia Newberry System Newberry Above: PFOA, PFOS | 6,480 |
| Kennett Square Municipal Water Works East Marlborough Above: PFOA, PFOS | 6,328 |
| East Petersburg Borough Water System East Petersburg Above: PFOA, PFOS | 6,215 |
| Titusville Municipal Water Titusville Above: PFOS | 6,146 |
| Aqua Pennsylvania Chalfont Bensalem Above: PFOA, PFOS | 5,900 |
| Coraopolis Water & Sewer Authority Moon Above: PFOA, PFOS | 5,804 |
| Beaver Borough Municipal Authority Beaver Above: PFOA, PFOS, PFHxS, Hazard Index | 5,799 |
| Hilltown Township Water&sewer Authority West Rockhill Above: PFOA, PFOS | 5,770 |
| Pennsylvania American Water – Frackville West Mahanoy Above: PFOS | 5,583 |
| Tunkhannock Borough Municipal Authority Tunkhannock Above: PFOS | 5,349 |
| Stewartstown Borough Water Authority Stewartstown Above: PFOA | 5,206 |
| Schwenksville Borough Authority Limerick Above: PFOA, PFOS | 5,200 |
| Aqua Pennsylvania Flying Hills Water Authority System Robeson Above: PFOA, PFOS | 5,100 |
| Montoursville Water Company Montoursville Above: PFOS | 4,983 |
| Buckingham Township Cold Spring Water System Buckingham Above: PFOA, PFOS | 4,760 |
| Shrewsbury Borough Water System Shrewsbury Above: PFOA, PFOS | 4,727 |
| Freeland Borough Municipal Water Authority Freeland Above: PFOA, PFOS | 4,610 |
| Millersburg Water Authority Upper Paxton Above: PFOS | 4,600 |
| Caernarvon Township Authority Caernarvon Above: PFOA | 4,245 |
| Ashland Area Water Authority Butler Above: PFOS | 4,200 |
| New Oxford Munci Authority New Oxford Above: PFOS | 3,963 |
| Aqua Pennsylvania Perkiomen Township Limerick Above: PFOA, PFOS | 3,600 |
| Plumstead Northern System Plumstead Above: PFOA, PFOS | 2,605 |
| EEI Meadows Complex Dallas Above: PFOS | 628 |
The same list, with PFOA and PFOS averages, is in the data download.
Which limits were exceeded
| PFAS | Federal limit | Systems above it |
|---|---|---|
| PFOA 3.9 million people | 4 ppt | 67 |
| PFOS 3.7 million people | 4 ppt | 73 |
| PFHxS 19,799 people | 10 ppt | 2 |
| PFNA 21,000 people | 10 ppt | 2 |
| GenX (HFPO-DA) | 10 ppt | 0 |
| Hazard Index 46,799 people | 1 | 4 |
"–" in the table above means not detected. A system can be above more than one limit. EPA proposed in May 2026 to rescind the PFHxS, PFNA, GenX and Hazard Index limits. That proposal is not final.
Pennsylvania has its own PFAS rules. 25 Pa. Code 109.202. MCLGs 8 (PFOA) and 14 (PFOS) ng/L. Compliance monitoring began 2024 (larger systems) / 2025 (<=350 people). Details. This report compares results with the federal limits only.
Data and how to cite it
- Download every Pennsylvania water system as CSV (PFOA and PFOS averages, systems above a limit, lead, violations).
- EPA's source file: UCMR 5 occurrence data.
Suggested citation:
Tap Water Results, "Pennsylvania PFAS results from EPA's final UCMR 5 data" (published Nov 14, 2026, EPA data file of Oct 15, 2026). https://tapwaterresults.com/pfas/pennsylvania/
You're welcome to quote and republish these figures with a link back. Questions from reporters: see contact.
Method
For each system we average each entry point's UCMR 5 results (non-detects count as zero, complete sets of samples only) and compare the highest entry-point average with the 2024 federal limit, using EPA's rounding. This is how EPA compares UCMR 5 results to the limits in its own data summary, and our national counts match EPA's published table within 2% (how we check). Results are monitoring data from 2023–2025, not compliance determinations, and treatment installed since then is not reflected. Full method.
Questions
How many Pennsylvania water systems have PFAS above the limit?
85 of the 360 Pennsylvania community water systems EPA tested in 2023–2025 (24%) had at least one entry-point average above a 2024 federal PFAS limit. They serve 4.2 million people. Nationally the share is 11%.
Are these systems violating the law?
Not yet. Systems have until 2029 to meet the 2024 limits, and EPA has proposed moving the PFOA and PFOS deadline to 2031 and rescinding the other limits. EPA's UCMR 5 results are monitoring data and do not determine compliance.
Which systems were tested?
EPA's UCMR 5 tested every community water system serving more than 3,300 people and a representative sample of smaller ones. Systems that were not tested have no federal result, which is not the same as having no PFAS.
All Pennsylvania water systems → · National results → · PFAS results for every state →
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.