Lake, 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 Lake in California · Population: 68,139
TRI sites such as Granite Construction Co - Highway 175; SDWIS systems such as HIGHLANDS MUTUAL WATER COMPANY; HIDDEN VALLEY LAKE CSD; KONOCTI COUNTY WATER DISTRICT; NPL sites such as Sulphur Bank Mercury Mine anchor Lake, CA's EPA extract. Derived burden score 29/100 (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 Lake include HIGHLANDS MUTUAL WATER COMPANY; HIDDEN VALLEY LAKE CSD; MT. KONOCTI MUTUAL WATER COMPANY, while Granite Construction Co - Highway 175 leads reported TRI pounds among local Form R filers. AQS median AQI 32 / peak 67 in 2024.
Burden score 29/100 (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 Lake -- 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.
Release-over-release change
What changed for Lake, CA: EPA TRI 2023 reporting year
Same facilities, both years
-52.9%
1 facilities that filed in 2022 and 2023
Whole inventory
-52.9%
374 lb → 176 lb, every facility that filed
- Lake, CA's total reported releases fell from 374 lb in 2022 to 176 lb in 2023, based on EPA TRI filings.
- Lake, CA's air releases fell from 374 lb in 2022 to 176 lb in 2023, based on EPA TRI filings.
- Lake, CA's chemicals reported fell from 2 in 2022 to 1 in 2023, based on EPA TRI filings.
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 | 361 (99%) | 2 | 0 | 67 |
| 2023 | 357 (98%) | 6 | 0 | 67 |
| 2022 | 359 (99%) | 4 | 0 | 76 |
| 2021 | 348 (98%) | 7 | 0 | 157 |
| 2020 | 341 (97%) | 6 | 1 | 190 |
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 (37)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| HIGHLANDS MUTUAL WATER COMPANY | 7,772 | 10 |
| HIDDEN VALLEY LAKE CSD | 6,235 | 1 |
| KONOCTI COUNTY WATER DISTRICT | 5,928 | 0 |
| LAKEPORT, CITY OF | 4,762 | 0 |
| MT. KONOCTI MUTUAL WATER COMPANY | 4,360 | 3 |
| KELSEYVILLE CO WATERWORKS DISTRICT 3 | 4,102 | 0 |
| LAKE COUNTY CSA 21 - NORTH LAKEPORT | 4,046 | 0 |
| COBB AREA COUNTY WATER DISTRICT | 3,515 | 1 |
| NICE MUTUAL WATER COMPANY | 2,929 | 0 |
| CLEARLAKE OAKS COUNTY WATER DISTRICT | 2,359 | 6 |
| LAKE COUNTY CSA 20 - SODA BAY | 2,003 | 0 |
| CALLAYOMI COUNTY WATER DISTRICT | 1,598 | 1 |
| LAKE COUNTY CSA 2 - SPRING VALLEY | 1,531 | 3 |
| BUCKINGHAM PARK WATER DISTRICT | 1,521 | 8 |
| LOWER LAKE COUNTY WATER DISTRICT | 1,326 | 0 |
| UPPER LAKE COUNTY WATER DISTRICT | 989 | 0 |
| LOCH LOMOND MUTUAL WATER CO | 693 | 1 |
| HARBOR VIEW MUTUAL WATER COMPANY | 550 | 7 |
| Middletown Rancheria Community Water System | 487 | 1 |
| LAKE COUNTY CSA 13 - KONO TAYEE | 449 | 0 |
| Big Valley Rancheria Water District | 417 | 0 |
| ANDERSON SPRINGS CSD | 373 | 0 |
| GLENHAVEN MUTUAL WATER COMPANY | 300 | 0 |
| CLEAR WATER MUTUAL WATER COMPANY | 252 | 0 |
| WALNUT COVE MOBILE ESTATES | 200 | 0 |
| PIER 1900 HOMEOWNER'S ASSOCIATION | 152 | 1 |
| CORINTHIAN BAY MUTUAL WATER COMPANY | 150 | 1 |
| CDF-KONOCTI CONSERVATION CAMP NO. 27 | 100 | 1 |
| Upper Lake Hardisty System | 98 | 0 |
| BLUE LAKES IMPROVEMENT CLUB | 90 | 1 |
| SUNRISE SHORE MUTUAL WATER COMPANY | 83 | 0 |
| LAZY S MOBILE RANCH | 73 | 37 |
| BAYCLIFF WATER | 70 | 0 |
| VILLA BLUE ESTATES WATER DISTRICT | 60 | 0 |
| INNISFREE WATER COMPANY | 56 | 0 |
| MOUNTAIN OF ATTENTION WATER | 26 | 0 |
| WINDFLOWER POINT MUTUAL WATER COMPANY | 25 | 0 |
TRI Facilities (1)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Granite Construction Co - Highway 175 | 550 lbs |
Superfund Sites (1)
| Site Name | Status | HRS Score |
|---|---|---|
| Sulphur Bank Mercury Mine | NPL Site | 44.42 |
Cities in Lake (11)
Frequently Asked Questions
What is the environmental risk level in Lake, California? ▼
Are there Superfund sites in Lake? ▼
How many toxic release facilities are in Lake? ▼
What is the air quality in Lake? ▼
Is the drinking water safe in Lake? ▼
What environmental agencies cover Lake? ▼
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.