County · California
Marin County, California: drinking water records
This overview covers 29 ZIP codes and 18 community water systems in Marin County. It also stands in for 0 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 |
|---|---|---|---|---|---|
| Marin Municipal Water District CA2110002 | 186,895 | 275 | 0 | 0 | 0 ppb |
| North Marin Water District CA2110003 | 61,691 | 176 | 0 | 0 | 0 ppb |
| NPS Ggnra CA2110350 | 18,447 | 120 | 0 | 0 | 0 ppb |
| Bolinas Community PUD CA2110005 | 2,483 | 120 | 0 | 0 | 0 ppb |
| Estero Mutual CA2100519 | 206 | 0 | 0 | 3 | 0 ppb |
| Green Gulch Farm CA2100565 | 75 | 0 | 0 | 1 | 0 ppb |
| Nicasio Valley Ranch Mutual CA2100579 | 36 | 0 | 0 | 6 | 4 ppb |
| North Marin WD - Pt. Reyes CA2110006 | 1,841 | 0 | 0 | 0 | 0 ppb |
| NPS Prns - Beaches CA2110502 | 1,560 | 0 | 0 | 0 | 8 ppb |
| Inverness Public Utility Dist CA2110001 | 1,445 | 0 | 0 | 0 | 2.7 ppb |
| Lawson S Landing CA2110008 | 946 | 0 | 0 | 0 | 0 ppb |
| Quail Hill Mobile Home Park CO0121633 | 878 | 0 | 0 | 0 | 0 ppb |
| Stinson Beach County Wtr Dist CA2110004 | 583 | 0 | 0 | 0 | 0 ppb |
| Coast Springs - Cal. Water Service (Puc) CA2110007 | 388 | 0 | 0 | 0 | 1.4 ppb |
| Muir Beach Community CA2100508 | 336 | 0 | 0 | 0 | 10 ppb |
| Security MHP CO0121750 | 150 | 0 | 0 | 0 | 3 ppb |
| Taylors Landing RV Park OR4192063 | 48 | 0 | 0 | 0 | 0 ppb |
| Blue Mountain Center CA2100549 | 35 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Marin County
No ZIP report in this county is published yet.
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.