Humboldt, 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 Humboldt in California · Population: 135,418
Humboldt, CA is tracked across three EPA datasets covering 3 Toxics Release Inventory (TRI) facilities, 47 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 35/100 (Moderate Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.
Industrial disclosures inside the county total 721.4K lbs of reported toxic releases under EPCRA Section 313, while 26 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 38 and a peak AQI of 86 in 2024, with 73% 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 | 266 (73%) | 100 | 0 | 86 |
| 2023 | 284 (78%) | 70 | 6 | 299 |
| 2022 | 340 (93%) | 25 | 0 | 74 |
| 2021 | 333 (91%) | 32 | 0 | 64 |
| 2020 | 318 (87%) | 44 | 3 | 180 |
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 (47)
| System | Population | Violations |
|---|---|---|
| EUREKA, CITY OF | 27,078 | 0 |
| ARCATA, CITY OF | 20,875 | 0 |
| MCKINLEYVILLE C.S.D. | 16,900 | 0 |
| FORTUNA, CITY OF | 12,133 | 0 |
| Hoopa Valley-Wide System | 3,500 | 0 |
| RIO DELL, CITY OF | 3,300 | 0 |
| GARBERVILLE SANITARY DISTRICT | 2,041 | 3 |
| FIELDBROOK GLENDALE C.S.D. | 1,845 | 0 |
| Bear River/Singley Hill | 1,530 | 0 |
| HYDESVILLE CO. W.D. | 1,366 | 1 |
| WILLOW CREEK C.S.D. | 1,298 | 5 |
| REDWAY C.S.D. | 1,207 | 1 |
| BLUE LAKE, CITY OF | 1,172 | 0 |
| TRINIDAD, CITY OF | 1,072 | 3 |
| JACOBY CREEK CWD | 924 | 0 |
| SCOTIA CSD | 906 | 4 |
| LOLETA C.S.D. | 828 | 4 |
| RESORT IMPROVEMENT DISTRICT #1 | 803 | 2 |
| MANILA COMMUNITY SERVICES DIST. | 750 | 0 |
| Bear River - Tish Non Village | 650 | 0 |
| ORLEANS C.S.D. | 636 | 5 |
| MIRANDA C.S.D. | 492 | 0 |
| WESTHAVEN C.S.D. | 490 | 8 |
| WEOTT C.S.D. | 448 | 20 |
| ORICK C.S.D. | 396 | 0 |
| RIVERSIDE CSD | 333 | 0 |
| MYERS FLAT M.W.S. INC. | 330 | 1 |
| PALMER CREEK CSD | 320 | 1 |
| PHILLIPSVILLE C.S.D. | 300 | 2 |
| GREEN DIAMOND RESOURCE COMPANY - KORBEL | 250 | 0 |
| Table Bluff (New) Reservation | 230 | 0 |
| ALDERPOINT COUNTY WATER | 185 | 16 |
| LAS PALMAS MOBILE HOME PARK | 120 | 1 |
| REDCREST WATER WORKS | 116 | 33 |
| WISEMANS MOBILE COURT | 114 | 1 |
| BIG LAGOON CSD | 112 | 0 |
| LAKESIDE MOBILE HOME & RV PARK | 110 | 1 |
| MILL CREEK M.W.C. | 85 | 1 |
| ORLEANS MUTUAL WATER COMPANY | 85 | 16 |
| BRICELAND C.S.D. | 75 | 2 |
| WADDINGTON W.W. | 75 | 0 |
| BIG LAGOON PARK WATER CO. | 70 | 0 |
| PALOMINO ESTATES WATER COMPANY | 64 | 4 |
| SEAWOOD ESTATES MUTUAL WATER COMPANY | 63 | 10 |
| RIVERBEND MOBILE HOME PARK | 60 | 1 |
| MOONSTONE HEIGHTS MWA | 33 | 0 |
| PINE GROVE MOBILE HOME PARK | 30 | 1 |
TRI Facilities (3)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Crystal Creamery Inc. DBA Humboldt Creamery | 547.2K lbs |
| 2 | Pg&e Humboldt Bay Power Plant | 174.2K lbs |
| 3 | Humboldt Sawmill Co & Cogeneration Plant | 4 lbs |
Cities in Humboldt (3)
Frequently Asked Questions
What is the environmental risk level in Humboldt, California? ▼
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Is the drinking water safe in Humboldt? ▼
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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.