Siskiyou, 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 Siskiyou in California · Population: 43,834
TRI sites such as Roseburg Forest Products Co. - Weed Facility; Pacific States Treating; Shasta Valley Asphalt; SDWIS systems such as YREKA, CITY OF; MT. SHASTA, CITY OF; LAKE SHASTINA C.S.D; NPL sites such as Blue Ledge Mine; J.H. Baxter & Co. anchor Siskiyou, CA's EPA extract. Derived burden score 37/100 (Moderate 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 Siskiyou include YREKA, CITY OF; MT. SHASTA, CITY OF; LAKE SHASTINA C.S.D, while Roseburg Forest Products Co. - Weed Facility leads reported TRI pounds among local Form R filers. AQS median AQI 41 / peak 94 in 2024.
Burden score 37/100 (Moderate 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 Siskiyou -- 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 Siskiyou, CA: EPA TRI 2023 reporting year
Same facilities, both years
+196.3%
2 facilities that filed in 2022 and 2023
Whole inventory
+196.3%
268 lb → 794 lb, every facility that filed
- Siskiyou, CA's total reported releases rose from 268 lb in 2022 to 794 lb in 2023, based on EPA TRI filings.
- Siskiyou, CA's off-site transfers rose from 268 lb in 2022 to 786 lb 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 | 284 (78%) | 82 | 0 | 94 |
| 2023 | 270 (74%) | 78 | 7 | 320 |
| 2022 | 269 (74%) | 86 | 2 | 454 |
| 2021 | 237 (65%) | 96 | 7 | 210 |
| 2020 | 272 (74%) | 71 | 10 | 468 |
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 (25)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| YREKA, CITY OF | 7,825 | 1 |
| MT. SHASTA, CITY OF | 3,642 | 11 |
| LAKE SHASTINA C.S.D | 2,790 | 2 |
| WEED, CITY OF | 2,662 | 2 |
| DUNSMUIR, CITY OF | 1,707 | 4 |
| MCCLOUD C.S.D. | 1,317 | 4 |
| MONTAGUE, CITY OF | 1,264 | 13 |
| HAPPY CAMP C.S.D. | 1,100 | 2 |
| DORRIS, CITY OF | 887 | 1 |
| ETNA, CITY OF | 720 | 0 |
| FORT JONES, TOWN OF | 695 | 0 |
| SISKIYOU LAKE HIGHLANDS MWC | 549 | 3 |
| SISKIYOU CO. ROLLING HILLS MWC | 300 | 0 |
| GRENADA SANITARY DISTRICT | 289 | 4 |
| HORNBROOK C.S.D. | 280 | 6 |
| LAKE SISKIYOU M.W.C. | 277 | 8 |
| LAKE SHASTA PINES RV PARK & CAMPGROUND | 168 | 1 |
| MONTE SHASTA M.W.C. | 150 | 0 |
| SISKIYOU CO.SERVICE AREA #5/CARRICK | 143 | 1 |
| SUN MOUNTAIN M.W.C. | 106 | 0 |
| Shackleford Creek Community Water System | 80 | 0 |
| TENNANT C.S.D. | 75 | 3 |
| CALLAHAN WATER DISTRICT | 70 | 3 |
| SHASTA VIEW HEIGHTS OWNERS ASSOCIATION | 48 | 0 |
| COLD CREEK MUTUAL WATER COMPANY | 25 | 0 |
TRI Facilities (4)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Roseburg Forest Products Co. - Weed Facility | 2.3K lbs |
| 2 | Pacific States Treating | 0 lbs |
| 3 | Shasta Valley Asphalt | 0 lbs |
| 4 | Timber Products Co. | 0 lbs |
Superfund Sites (2)
| Site Name | Status | HRS Score |
|---|---|---|
| Blue Ledge Mine | NPL Site | 50.28 |
| J.H. Baxter & Co. | NPL Site | 34.78 |
Cities in Siskiyou (15)
Frequently Asked Questions
What is the environmental risk level in Siskiyou, California? ▼
Are there Superfund sites in Siskiyou? ▼
How many toxic release facilities are in Siskiyou? ▼
What is the air quality in Siskiyou? ▼
Is the drinking water safe in Siskiyou? ▼
What environmental agencies cover Siskiyou? ▼
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.