248 public water systems in Washington were sampled in EPA's UCMR 5 programme (2023–2025); we show six PFAS and lithium. Read 2026-10-31.
35 of 248 systems had at least one sample above a 2024 federal limit; 92 had at least one PFAS found above the reporting level; 156 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 7,191,717 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.
Pages for these are being added in stages. The data for all 248 systems is in the public dataset.
| System | People served | UCMR 5 result |
|---|---|---|
| Spokane City of Spokane City of | 346,138 | Above the 2024 limit in at least one sample |
| Bellevue City of Bellevue City of | 321,349 | None detected (below the reporting level) |
| Alderwood Water District Alderwood Water District | 245,715 | None detected (below the reporting level) |
| Everett Public Works Dept. City of Everett Public Works Dept. City of | 215,774 | None detected (below the reporting level) |
| Kent Water Department Kent Water Department | 166,421 | Detected, below the 2024 limit |
| Redmond Water System City of Redmond Water System City of | 163,335 | Above the 2024 limit in at least one sample |
| Clark Public Utilities Clark Public Utilities | 153,526 | Above the 2024 limit in at least one sample |
| Lakehaven Water and Sewer District Lakehaven Water and Sewer District | 148,809 | Above the 2024 limit in at least one sample |
| Bellingham-Water Division City of Bellingham-Water Division City of | 141,127 | None detected (below the reporting level) |
| Olympia City of Olympia City of | 126,966 | Above the 2024 limit in at least one sample |
| Kennewick City of Kennewick City of | 118,164 | Above the 2024 limit in at least one sample |
| Pasco Water Department Pasco Water Department | 115,102 | None detected (below the reporting level) |
| Yakima Water Division City of Yakima Water Division City of | 112,858 | None detected (below the reporting level) |
| Skagit County Pud 1 Judy Res Skagit County Pud 1 Judy Res | 111,415 | None detected (below the reporting level) |
| Renton City of Renton City of | 108,091 | Detected, below the 2024 limit |
| Auburn City of Auburn City of | 107,655 | Detected, below the 2024 limit |
| Richland City of Richland City of | 106,499 | Above the 2024 limit in at least one sample |
| Lacey Water Department Lacey Water Department | 105,178 | Detected, below the 2024 limit |
| Highline Water District Highline Water District | 100,170 | None detected (below the reporting level) |
| Northshore Utility District Northshore Utility District | 99,789 | None detected (below the reporting level) |
| Puyallup City of Puyallup City of | 94,520 | Detected, below the 2024 limit |
| Marysville Utilities Marysville Utilities | 88,582 | None detected (below the reporting level) |
| Lakewood Water District Lakewood Water District | 82,425 | Above the 2024 limit in at least one sample |
| Sammamish Plateau Water & Sewer Sammamish Plateau Water & Sewer | 79,362 | Above the 2024 limit in at least one sample |
| Soos Creek Water & Sewer District Soos Creek Water & Sewer District | 74,172 | None detected (below the reporting level) |