Tuolumne County, CA
The federal environmental record for Tuolumne County (population 54,204): what is on file, where it is, and what remains open. Sources and retrieval dates are on the methodology page.
0
Superfund NPL sites
3
federal cleanup sites
2
PFAS-detecting water systems
1
TRI facilities
13
open tank releases
Drinking water: PFAS testing
Public water systems serving Tuolumne with at least one PFAS detection under UCMR5. The federal limit for PFOA and PFOS is 4 ng/L; EPA proposed in May 2026 to rescind the limits for the other compounds, which are shown for information.
| System | Highest results | Reading |
|---|---|---|
| GROVELAND COMMUNITY SERV DIST CA5510009 | PFBA: 7.2 ng/L PFOS: 4.9 ng/L | above final limit |
| TUD-WARDS FERRY RANCHES CA5500363 | PFPeA: 4.8 ng/L PFHxA: 3.8 ng/L PFBS: 3 ng/L | detected |
On a system with detections? Testing and treatment options
Facilities reporting toxic releases (2024)
1 facilities in Tuolumne filed TRI reports for 2024, totalling 0 lb released.
| Facility | City | Top chemicals | Total released |
|---|---|---|---|
| SPI SONORA DIV | SONORA | Dioxin and dioxin-like compounds | 0 lb |
Underground fuel tanks
EPA's UST Finder records 31 tank facilities in Tuolumne: 81 tanks in service and 0 closed. 132 fuel releases are on record, of which 13 remain open. Open releases are cleanups that have not reached "no further action".
Radon
EPA maps Tuolumne as Zone 2, moderate predicted indoor radon (2 to 4 pCi/L average). Radon and air quality are covered in depth on lung.com.
The record for one specific address
County figures blur what matters: distance. The Address Environmental Report runs these same federal datasets against one address and reports every site, tank, polluter and water result around it, with distances, in about a minute.
Get the report - $39All federal cleanup sites on file
The wider Superfund enterprise inventory (SEMS) for Tuolumne, including sites assessed but never listed. Presence here records that EPA had reason to look, not a finding of danger.
- CHICKEN RANCH RANCHERIA OF ME-WUK INDIANS OF CALIFORNIAJAMESTOWN
- HERITAGE DRY CLEANERSSONORA
- STANISLAUS NAT FORESTSONORA