County · California
Mendocino County, California: drinking water records
This overview covers 26 ZIP codes and 44 community water systems in Mendocino County. It also stands in for 9 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Fort Bragg, City of CA2310001 | 6,919 | 120 | 0 | 1 | 0 ppb |
| Ukiah, City of CA2310003 | 16,607 | 480 | 9 | 0 | 0 ppb |
| Willits, City of CA2310004 | 6,175 | 120 | 0 | 0 | 0 ppb |
| Millview County Water District CA2310006 | 5,500 | 240 | 0 | 0 | 0 ppb |
| Redwood Valley County Water District CA2310008 | 5,200 | 120 | 0 | 0 | 0 ppb |
| Willow County Water District CA2310005 | 3,797 | 60 | 0 | 0 | 0 ppb |
| Brooktrails Township CSD CA2310009 | 3,632 | 120 | 0 | 0 | 0 ppb |
| Rogina Water Company INC. CA2310002 | 2,554 | 0 | 0 | 1 | 0 ppb |
| City of 10,000 Buddhas CA2300731 | 400 | 0 | 0 | 1 | 0 ppb |
| Elk County Water District CA2300514 | 380 | 0 | 0 | 1 | 0 ppb |
| Woodside RV Park CA2300644 | 280 | 0 | 0 | 1 | 10 ppb |
| Ridgewood Water System CA2300708 | 265 | 0 | 0 | 1 | 0 ppb |
| Irish Beach Water District CA2310012 | 254 | 0 | 0 | 1 | 0 ppb |
| Surfwood Mutual Water Corporation CA2300590 | 160 | 0 | 0 | 31 | 6.9 ppb |
| The Hideout at Glenwood Springs CO0223343 | 94 | 0 | 0 | 1 | 1.1 ppb |
| Bella Shores Mobile Home Park CA2300646 | 80 | 0 | 0 | 1 | 0 ppb |
| Yokayo Tribe of Indians CA2300837 | 75 | 0 | 0 | 1 | 0 ppb |
| Original Sherwood Valley Rancheria 090605021 | 60 | 0 | 0 | 2 | 1 ppb |
| Branscomb Mobile Home Park CA2300663 | 42 | 0 | 0 | 2 | 0 ppb |
| North Gualala Water Company CA2310007 | 2,593 | 0 | 0 | 0 | 0 ppb |
| Laytonville County Water District CA2310011 | 1,152 | 0 | 0 | 0 | 0 ppb |
| Hopland Public Utility District CA2310010 | 1,076 | 0 | 0 | 0 | 0 ppb |
| Coyote Valley System 090600030 | 850 | 0 | 0 | 0 | 5 ppb |
| Dolphin Isle Marina CA2300743 | 560 | 0 | 0 | 0 | 0 ppb |
| Calpella County Water District CA2300507 | 548 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Mendocino County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 95420, 95427, 95429, 95463, 95466, 95469, 95494, 95585, 95587.
Sources and scope
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.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.