Mono, CA
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Fixed caps: facilities ≤25 pts (50+ = max), log10 releases ≤25 pts, Superfund ≤25 pts (5/site), health-violation systems ≤15 pts (3/system), high-chemical facilities ≤10 pts. Bands: High ≥60, Moderate ≥30. See methodology.
Environmental data for Mono in California · Population: 13,169
TRI sites such as Marine Corps Mountain Warfare Training Center; SDWIS systems such as MAMMOTH CWD; JUNE LAKE PUD - DOWN CANYON; JUNE LAKE PUD VILLAGE anchor Mono, CA's EPA extract. Derived burden score 25/100 (Low Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
Health-flagged SDWIS rows in Mono include MAMMOTH CWD; JUNE LAKE PUD - DOWN CANYON; JUNE LAKE PUD VILLAGE, while Marine Corps Mountain Warfare Training Center leads reported TRI pounds among local Form R filers. AQS median AQI 19 / peak 69 in 2024.
Burden score 25/100 (Low Risk) is the only weighted composite on this page. The tables below list every TRI facility, SDWIS system, and Superfund site EPA has on record for Mono -- not just the names called out above -- reproducing the disclosure history as filed, not a current-safety verdict. Extract current as of 2026-08-25.
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 | 341 (93%) | 25 | 0 | 69 |
| 2023 | 325 (89%) | 35 | 1 | 1829 |
| 2022 | 276 (76%) | 61 | 5 | 8368 |
| 2021 | 260 (71%) | 78 | 12 | 2971 |
| 2020 | 183 (50%) | 117 | 13 | 2088 |
Source: 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 (34)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| MAMMOTH CWD | 8,234 | 2 |
| JUNE LAKE PUD - DOWN CANYON | 2,810 | 5 |
| JUNE LAKE PUD VILLAGE | 2,763 | 7 |
| Bishop Paiute-Shoshone Tribe | 2,735 | 3 |
| HIGHLAND MOBILE HOME PARK | 1,400 | 2 |
| USMC/MTN WARFARE TRNG CTR - BRIDGEPORT | 1,200 | 0 |
| MEADOWCREEK MUTUAL WATER COMPANY | 764 | 2 |
| LEE VINING PUBLIC UTILITY DISTRICT | 672 | 0 |
| BRIDGEPORT PUD | 524 | 93 |
| MOUNTAIN MEADOWS MWC | 505 | 0 |
| USMC - HOUSING COLEVILLE | 424 | 0 |
| LOWER ROCK CREEK MUTUAL WATER CO. | 310 | 1 |
| PINE CREEK VILLAGE | 240 | 42 |
| CROWLEY LAKE TRAILER PARK | 230 | 1 |
| Utu Utu Gwaitu Paiute Tribe | 222 | 46 |
| CROWLEY LAKE MUTUAL WATER COMPANY | 175 | 0 |
| WILSON CIRCLE MUTUAL WATER COMPANY | 158 | 0 |
| BIRCHIM COMMUNITY SERVICE DISTRICT | 150 | 0 |
| SIERRA GRANDE ESTATES MUTUAL WATER CO. | 138 | 2 |
| CARTAGO MUTUAL WATER COMPANY | 132 | 1 |
| CDF - OWENS VALLEY CONSERVATION CAMP | 94 | 10 |
| RAWSON CREEK MUTUAL WATER COMPANY | 90 | 0 |
| WHEELER CREST CSD | 86 | 0 |
| SIERRA EAST HOA | 84 | 24 |
| KEOUGH'S HOT SPRINGS | 75 | 5 |
| SUNLAND VILLAGE MOBILE HOME PARK | 73 | 0 |
| VALLEY VISTA MUTUAL WATER COMPANY | 70 | 0 |
| LUNDY MUTUAL WATER COMPANY | 70 | 0 |
| RANCH ROAD ESTATES MUTUAL WATER COMPANY | 65 | 0 |
| ASPENDELL MUTUAL WATER COMPANY | 60 | 0 |
| BROOKSIDE ESTATES MUTUAL WATER COMPANY | 59 | 0 |
| CHALFANT VALLEY WEST M.W.C. | 45 | 0 |
| SIERRA NORTH COMMUNITY SERVICE DISTRICT | 42 | 0 |
| VAN LOON WATER ASSOCIATION | 25 | 0 |
TRI Facilities (1)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Marine Corps Mountain Warfare Training Center | 803 lbs |
Cities in Mono (8)
Frequently Asked Questions
What is the environmental risk level in Mono, California? ▼
Are there Superfund sites in Mono? ▼
How many toxic release facilities are in Mono? ▼
What is the air quality in Mono? ▼
Is the drinking water safe in Mono? ▼
What environmental agencies cover Mono? ▼
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.