152 public water systems in Arizona were sampled in EPA's UCMR 5 programme (2023–2025); we show six PFAS and lithium. Read 2026-10-31.
25 of 152 systems had at least one sample above a 2024 federal limit; 142 had at least one PFAS found above the reporting level; 10 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 5,790,689 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 152 systems is in the public dataset.
| System | People served | UCMR 5 result |
|---|---|---|
| Gilbert, Town of Gilbert, Town of | 247,600 | Above the 2024 limit in at least one sample |
| Chandler City of Chandler City of | 247,328 | Detected, below the 2024 limit |
| Scottsdale City of Scottsdale City of | 241,361 | Detected, below the 2024 limit |
| Glendale City of Glendale City of | 234,766 | Detected, below the 2024 limit |
| Peoria City of Peoria City of | 187,676 | Above the 2024 limit in at least one sample |
| Tempe City of Tempe City of | 165,000 | Above the 2024 limit in at least one sample |
| Arizona Water Co - Pinal Valley Arizona Water Co - Pinal Valley | 134,432 | Detected, below the 2024 limit |
| Epcor Water - Agua Fria Epcor Water - Agua Fria | 128,040 | None detected (below the reporting level) |
| Yuma City of Yuma City of | 103,264 | None detected (below the reporting level) |
| City of Avondale City of Avondale | 96,130 | Above the 2024 limit in at least one sample |
| Queen Creek Town of Queen Creek Town of | 95,502 | None detected (below the reporting level) |
| Epcor - San Tan Epcor - San Tan | 87,435 | None detected (below the reporting level) |
| Gwr - Santa Cruz Water Co. Inc. Gwr - Santa Cruz Water Co. Inc. | 84,000 | None detected (below the reporting level) |
| Flagstaff City of Flagstaff City of | 79,796 | None detected (below the reporting level) |
| Arizona Water Co - Apache Junction Arizona Water Co - Apache Junction | 62,055 | None detected (below the reporting level) |
| Liberty Water Lpsco Liberty Water Lpsco | 57,070 | Above the 2024 limit in at least one sample |
| Town of Prescott Valley Town of Prescott Valley | 57,048 | None detected (below the reporting level) |
| City of Lake Havasu City of Lake Havasu | 54,610 | Detected, below the 2024 limit |
| Goodyear Water Department Goodyear Water Department | 50,001 | Above the 2024 limit in at least one sample |
| Metropolitan Dwid Metropolitan Dwid | 45,570 | Detected, below the 2024 limit |
| Kingman Municipal Water Kingman Municipal Water | 45,000 | None detected (below the reporting level) |
| Oro Valley Water Utility Oro Valley Water Utility | 42,316 | None detected (below the reporting level) |
| Prescott City of Prescott City of | 42,217 | Above the 2024 limit in at least one sample |
| Surprise City of - Mountain Vista Surprise City of - Mountain Vista | 40,007 | None detected (below the reporting level) |
| El Mirage City of El Mirage City of | 39,884 | Detected, below the 2024 limit |