State
California: drinking water records
EPA lists 3,067 community water systems serving homes in California. 697 took part in EPA's national PFAS survey (UCMR 5), and 239 found at least one PFAS above the level laboratories can measure.
In focus3,067community water systems
Public records. Clearer context.
0
ZIP reports published
3,067
community water systems
980
systems with a health-based violation since 2016
213
systems that reached the lead action level since 2016
Counties
- Alameda County 18 systems
- Alpine County 7 systems
- Amador County 25 systems
- Butte County 42 systems
- Calaveras County 19 systems
- Colusa County 10 systems
- Contra Costa County 43 systems
- Del Norte County 23 systems
- El Dorado County 20 systems
- Fresno County 109 systems
- Glenn County 14 systems
- Humboldt County 52 systems
- Imperial County 32 systems
- Inyo County 53 systems
- Kern County 172 systems
- Kings County 23 systems
- Lake County 44 systems
- Lassen County 19 systems
- Los Angeles County 202 systems
- Madera County 69 systems
- Marin County 18 systems
- Mariposa County 12 systems
- Mendocino County 44 systems
- Merced County 24 systems
- Modoc County 10 systems
- Mono County 20 systems
- Monterey County 158 systems
- Napa County 31 systems
- Nevada County 24 systems
- Orange County 43 systems
- Placer County 52 systems
- Plumas County 30 systems
- Riverside County 110 systems
- Sacramento County 65 systems
- San Benito County 31 systems
- San Bernardino County 149 systems
- San Diego County 93 systems
- San Francisco County 6 systems
- San Joaquin County 95 systems
- San Luis Obispo County 74 systems
- San Mateo County 36 systems
- Santa Barbara County 67 systems
- Santa Clara County 76 systems
- Santa Cruz County 52 systems
- Shasta County 62 systems
- Sierra County 8 systems
- Siskiyou County 32 systems
- Solano County 27 systems
- Sonoma County 134 systems
- Stanislaus County 70 systems
- Sutter County 9 systems
- Tehama County 48 systems
- Trinity County 17 systems
- Tulare County 94 systems
- Tuolumne County 51 systems
- Ventura County 68 systems
- Yolo County 18 systems
- Yuba County 21 systems
ZIP reports
Sources
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.