Tuolumne, CA
A PlainEnviro-computed score from reported facility/violation counts, not an official EPA rating, health forecast, or population-adjusted rate. See methodology.
Environmental data for Tuolumne in California · Population: 54,873
Tuolumne, CA is tracked across three EPA datasets covering 1 Toxics Release Inventory (TRI) facility, 38 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 17/100 (Low Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.
Industrial disclosures inside the county total 2 lbs of reported toxic releases under EPCRA Section 313, while 13 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 40 and a peak AQI of 115 in 2024, with 81% of observed days rated "Good" (0–50).
All figures below draw directly from federal EPA records, TRI self-reported emissions, SDWIS compliance history, NPL Hazard Ranking System scores, and AQS daily AQI summaries, and are not adjusted, weighted, or forecast. A past violation or elevated score does not itself indicate current unsafe conditions; it documents the regulatory and disclosure history publicly filed with the U.S. Environmental Protection Agency through the most recent reporting cycle.
Air Quality History (2020–2024)
EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.
| Year | Good | Moderate | Unhealthy (SG) | Max AQI |
|---|---|---|---|---|
| 2024 | 286 (81%) | 64 | 4 | 115 |
| 2023 | 237 (82%) | 51 | 2 | 112 |
| 2022 | 237 (95%) | 12 | 1 | 108 |
| 2021 | 295 (82%) | 63 | 2 | 136 |
| 2020 | 277 (78%) | 71 | 5 | 143 |
Source: EPA Air Quality System (AQS) Annual AQI by County EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)
For real-time air quality readings and pollutant breakdowns in California, see the EPA's AirNow.gov.
Water Systems (38)
| System | Population | Violations |
|---|---|---|
| TUD - UPPER BASIN WATER SYSTEM | 13,280 | 0 |
| TUD - SONORA/JAMESTOWN WATER SYSTEM | 11,054 | 0 |
| TUD - COLUMBIA WATER SYSTEM | 5,463 | 0 |
| CDCR - SIERRA CONSERVATION CENTER | 3,571 | 8 |
| GROVELAND COMMUNITY SERV DIST | 3,400 | 3 |
| LAKE DON PEDRO CSD | 3,240 | 1 |
| TWAIN HARTE COMMUNITY SERVICES DISTRICT | 2,378 | 0 |
| MI WUK VILLAGE MUT WTR CO | 2,163 | 0 |
| COLD SPRINGS WATER CO | 1,771 | 0 |
| TUD - PONDEROSA | 1,767 | 0 |
| TUD - TUOLUMNE WATER SYSTEM | 1,761 | 0 |
| PINECREST PERMITTEES ASSN | 1,298 | 1 |
| PHOENIX LAKE ESTATES CC MWC | 1,168 | 0 |
| SONORA MEADOWS MUTUAL WTR CO | 1,123 | 2 |
| DON PEDRO REC AG:FLEM.MEADOWS | 1,041 | 0 |
| TUD-APPLE VALLEY ESTATES | 826 | 0 |
| BELLEVIEW OAKS MUTUAL WATER CO | 468 | 0 |
| MI WUK HEIGHTS MWC | 445 | 0 |
| SLIDE INN SNOWBOWL WATER CO | 417 | 0 |
| SIERRA PARK WATER COMPANY INC. | 400 | 5 |
| SIERRA VILLAGE MUTUAL WATER CO | 361 | 0 |
| LEISURE PINES MUTUAL WATER CO | 340 | 1 |
| RAWHIDE MUTUAL WATER COMPANY | 269 | 0 |
| SUGAR PINE RV RESORT | 219 | 0 |
| MOTHER LODE MOBILE ESTATES | 210 | 0 |
| TWAIN HARTE VALLEY MWC | 202 | 1 |
| ALPINE ACRES MUTUAL WATER CO | 195 | 1 |
| MULLER MUTUAL WATER COMPANY | 154 | 0 |
| CAL FIRE BASELINE CONSERVATION CAMP | 150 | 7 |
| SIERRA TWAIN HARTE MHP | 129 | 0 |
| 49ER TRAILER RANCH | 115 | 0 |
| LONG BARN PROPERTY OWNERS | 97 | 0 |
| TUD-PEACEFUL PINES WATER SYSTEM | 92 | 0 |
| YOSEMITE VISTA ESTATES | 85 | 0 |
| TUD-WARDS FERRY RANCHES | 62 | 1 |
| PONDEROSA MOBILE HOME PARK | 52 | 2 |
| Tuolumne Me-Wuk Ridgeline | 30 | 0 |
| SIERRA VILLAGE MOBILE HOME PARK | 22 | 1 |
TRI Facilities (1)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Spi Sonora Div | 2 lbs |
Cities in Tuolumne (1)
Frequently Asked Questions
What is the environmental risk level in Tuolumne, California? ▼
Are there Superfund sites in Tuolumne? ▼
How many toxic release facilities are in Tuolumne? ▼
What is the air quality in Tuolumne? ▼
Is the drinking water safe in Tuolumne? ▼
What environmental agencies cover Tuolumne? ▼
What does this county environmental profile show?
This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.
Read our methodology - how this data is sourced, computed, and verified.