390 public water systems in Pennsylvania were sampled in EPA's UCMR 5 programme (2023–2025); we show six PFAS and lithium. Read 2026-10-31.
119 of 390 systems had at least one sample above a 2024 federal limit; 204 had at least one PFAS found above the reporting level; 186 had none found above the reporting level.
A single sample above a 2024 limit is a measurement, not a violation. Compliance is judged on running yearly averages, and water systems have until 2029 to meet the limits. On 20 May 2026 EPA proposed giving qualifying systems until 2031 for PFOA and PFOS and removing the limits for PFHxS, PFNA and HFPO-DA; those proposals were not final when we last checked (5 Nov 2026). Counts are per system, not per person; population figures are available only for systems serving more than 25,000 people (about 8,345,167 people across those systems here). UCMR 5 was a one-time national monitoring programme (2023–2025). The results are a snapshot at the system's entry points or taps on the sample dates, not a continuous measurement and not a compliance record.
| System | People served | UCMR 5 result |
|---|---|---|
| Philadelphia Philadelphia Water Department | 1,600,000 | Above the 2024 limit in at least one sample |
| Aqua Pennsylvania Main System Aqua Pa Main System | 822,600 | Above the 2024 limit in at least one sample |
| Pennsylvania American Water Co, Pittsburgh Pa Amer Water Co-Pittsburgh | 686,000 | None detected (below the reporting level) |
| Pittsburgh Pittsburgh Water & Sewer Auth | 520,000 | None detected (below the reporting level) |
Pages for these are being added in stages. The data for all 390 systems is in the public dataset.
| System | People served | UCMR 5 result |
|---|---|---|
| Erie City Water Authority Erie City Water Authority | 220,001 | None detected (below the reporting level) |
| York Water Co York Water Co | 206,762 | None detected (below the reporting level) |
| West View Water Authority West View Water Authority | 200,000 | None detected (below the reporting level) |
| Mawc Sweeney Plant Mawc Sweeney Plant | 143,000 | None detected (below the reporting level) |
| Chester Water Authority Chester Water Authority | 140,437 | Above the 2024 limit in at least one sample |
| Pa Amer Water Co Lake Scranton Pa Amer Water Co Lake Scranton | 137,142 | Above the 2024 limit in at least one sample |
| Mawc Yough Plant Mawc Yough Plant | 133,000 | None detected (below the reporting level) |
| Wilkinsburg-Penn Jt Water Auth Wilkinsburg-Penn Jt Water Auth | 125,000 | None detected (below the reporting level) |
| City of Lancaster, Pa City of Lancaster, Pa | 120,000 | Above the 2024 limit in at least one sample |
| Lca Allentown Division Lca Allentown Division | 118,000 | Above the 2024 limit in at least one sample |
| City of Bethlehem City of Bethlehem | 117,259 | None detected (below the reporting level) |
| Suez Water Pa Suez Water Pa | 110,000 | Detected, below the 2024 limit |
| Pa American Water Co West Pa American Water Co West | 105,127 | Above the 2024 limit in at least one sample |
| Easton Area Water System Easton Area Water System | 96,867 | None detected (below the reporting level) |
| Reading Area Water Authority Reading Area Water Authority | 95,100 | Above the 2024 limit in at least one sample |
| North Penn Water Authority North Penn Water Authority | 91,941 | Above the 2024 limit in at least one sample |
| Pa American Norristown Pa American Norristown | 88,885 | Detected, below the 2024 limit |
| North Wales Water Authority North Wales Water Authority | 72,496 | Above the 2024 limit in at least one sample |
| State College Boro Water Auth. State College Boro Water Auth. | 72,000 | None detected (below the reporting level) |
| Capital Region Water Capital Region Water | 66,540 | None detected (below the reporting level) |
| Lower Bucks Co Joint Mun Auth Lower Bucks Co Joint Mun Auth | 63,007 | None detected (below the reporting level) |
| Altoona Water Authority Altoona Water Authority | 62,500 | None detected (below the reporting level) |
| Hampton Shaler Water Authority Hampton Shaler Water Authority | 61,949 | None detected (below the reporting level) |
| Aqua Pa Bensalem Aqua Pa Bensalem | 59,001 | Above the 2024 limit in at least one sample |
| Paw Ceasetown Paw Ceasetown | 58,467 | None detected (below the reporting level) |