County · California
Tuolumne County, California: drinking water records
This overview covers 14 ZIP codes and 51 community water systems in Tuolumne County. It also stands in for 1 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 |
|---|---|---|---|---|---|
| Groveland Community Serv Dist CA5510009 | 3,400 | 360 | 2 | 3 | 0 ppb |
| Tud - Upper Basin Water System CA5510012 | 13,280 | 360 | 0 | 0 | 0 ppb |
| Tud - Sonora/Jamestown Water System CA5510001 | 11,054 | 120 | 0 | 0 | 0 ppb |
| Tud - Columbia Water System CA5510013 | 5,463 | 240 | 0 | 0 | 4.7 ppb |
| Cdcr - Sierra Conservation Center CA5510851 | 3,571 | 0 | 0 | 4 | 0 ppb |
| Lake Don Pedro CSD CA5510008 | 3,240 | 0 | 0 | 1 | 0 ppb |
| Pinecrest Permittees Assn CA5510004 | 1,298 | 0 | 0 | 1 | 12.1 ppb |
| Del Oro Water Company - Strawberry Div. CA5510007 | 1,295 | 0 | 0 | 2 | 0.9 ppb |
| Sonora Meadows Mutual Wtr Co CA5510023 | 1,123 | 0 | 0 | 1 | 0 ppb |
| Leisure Pines Mutual Water Co CA5500053 | 340 | 0 | 0 | 1 | 12.6 ppb |
| Peppermint Creek MHP CA5500116 | 280 | 0 | 0 | 2 | 0 ppb |
| Twain Harte Valley Mwc CA5500080 | 202 | 0 | 0 | 1 | 0 ppb |
| Alpine Acres Mutual Water Co CA5500041 | 195 | 0 | 0 | 1 | 0 ppb |
| Cal Fire Baseline Conservation Camp CA5510852 | 150 | 0 | 0 | 6 | 0 ppb |
| Tud-Wards Ferry Ranches CA5500363 | 62 | 60 | 3 | 0 | 0 ppb |
| Ponderosa Mobile Home Park CA5500092 | 52 | 0 | 0 | 1 | 0 ppb |
| Sierra Village Mobile Home Park CA5500353 | 22 | 0 | 0 | 1 | 2.6 ppb |
| Twain Harte Community Services District CA5510005 | 2,378 | 0 | 0 | 0 | 0 ppb |
| Mi Wuk Village Mut Wtr Co CA5510006 | 2,163 | 0 | 0 | 0 | 12 ppb |
| Cold Springs Water Co CA5510011 | 1,771 | 0 | 0 | 0 | 0 ppb |
| Tud - Ponderosa CA5510002 | 1,767 | 0 | 0 | 0 | 0 ppb |
| Tud - Tuolumne Water System CA5510003 | 1,761 | 0 | 0 | 0 | 0 ppb |
| Phoenix Lake Estates Cc Mwc CA5510026 | 1,168 | 0 | 0 | 0 | 0 ppb |
| Sonora Water Resources, INC CA5510024 | 1,154 | 0 | 0 | 0 | 0 ppb |
| Don Pedro Rec Ag:flem.Meadows CA5500048 | 1,041 | 0 | 0 | 0 | 0 ppb |
ZIP reports in Tuolumne 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: 95309.
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.