Okanogan, WA
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 Okanogan in Washington · Population: 42,811
TRI sites such as US Cbp Oroville Port of Entry WA0021; SDWIS systems such as OMAK CITY OF; BREWSTER CITY OF; OKANOGAN WATER DEPARTMENT CITY OF; NPL sites such as Silver Mountain Mine anchor Okanogan, WA's EPA extract. Derived burden score 27/100 (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 Okanogan include Monse-Riggan Camp; INCHELIUM WATER DISTRICT; NESPELEM AGENCY, while US Cbp Oroville Port of Entry WA0021 leads reported TRI pounds among local Form R filers. AQS median AQI 38 / peak 102 in 2024.
Burden score 27/100 (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 Okanogan -- 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 | 225 (61%) | 140 | 1 | 102 |
| 2023 | 185 (51%) | 171 | 2 | 299 |
| 2022 | 175 (48%) | 185 | 4 | 248 |
| 2021 | 146 (40%) | 193 | 5 | 354 |
| 2020 | 196 (54%) | 157 | 1 | 618 |
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 Washington, see the EPA's AirNow.gov.
Water Systems (62)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| OMAK CITY OF | 4,940 | 0 |
| BREWSTER CITY OF | 3,843 | 0 |
| OKANOGAN WATER DEPARTMENT CITY OF | 3,817 | 0 |
| OROVILLE CITY OF | 3,256 | 0 |
| TONASKET WATER SYSTEM | 2,398 | 0 |
| COULEE DAM WATER DEPT | 1,454 | 0 |
| WINTHROP TOWN OF | 1,350 | 0 |
| TWISP TOWN OF | 1,173 | 0 |
| Monse-Riggan Camp | 1,165 | 3 |
| PATEROS WATER DEPARTMENT | 1,149 | 0 |
| JAW FARMS INC | 636 | 0 |
| DUCK LAKE WATER ASSOCIATION | 635 | 0 |
| BREWSTER FLAT DOMESTIC WATER ASSN | 542 | 0 |
| INCHELIUM WATER DISTRICT | 540 | 3 |
| NESPELEM WATER DEPT | 510 | 0 |
| P AND G ORCHARDS CAMP 2 | 489 | 0 |
| NESPELEM AGENCY | 445 | 2 |
| RIVERSIDE TOWN OF | 429 | 0 |
| OMAK HUD | 380 | 8 |
| ELMER CITY WATER SYSTEM | 368 | 0 |
| KELLER | 340 | 6 |
| CORRAL SPRINGS WATER SYSTEM | 336 | 0 |
| PROGRESSIVE FLAT WATER ASSN | 335 | 1 |
| Crane Ranch | 329 | 0 |
| ROCKY RIVER ROAD COMMUNITY SITE | 260 | 8 |
| SANDFLAT WATER ASSOCIATION | 260 | 0 |
| SUNCREST PLAT WATER SYSTEM | 260 | 0 |
| COLEMAN BUTTE WATER ASSN | 250 | 0 |
| LOOMIS WATER USERS ASSN INC | 225 | 0 |
| PASCHAL SHERMAN INDIAN SCHOOL | 220 | 15 |
| HANSON HARBOR HOMEOWNERS ASSN | 220 | 0 |
| AFC RANCH 1 | 217 | 0 |
| RIVER ROAD MOBILE HOME PARK | 150 | 2 |
| ASTON ESTATES | 141 | 0 |
| AFC RANCH 2 | 125 | 0 |
| SEATONS GROVE | 115 | 4 |
| CRUMBACHER ESTATES WATER SYSTEM | 111 | 0 |
| MARTIN CREEK COMMUNITY ASSN | 108 | 16 |
| HOMESTEAD MOBILE HOME PARK | 105 | 0 |
| M J TRAILER RANCH | 100 | 0 |
| MALOTT | 95 | 8 |
| EDELWEISS MAINTENANCE COMMISSION | 95 | 0 |
| PINE FOREST WATER SYSTEM | 90 | 0 |
| OLD ORCHARD ESTATES WATER SYSTEM | 86 | 0 |
| LOST RIVER AIRPORT ASSOCIATION | 72 | 0 |
| WOLF CREEK PROPERTY OWNERS ASSN | 71 | 0 |
| PINECREST SUBDIVISON OWNERS | 63 | 0 |
| CASCADE FOOTHILLS | 61 | 0 |
| VISTA VUE WATER USERS ASSN | 60 | 0 |
| EMANUEL HEIGHTS WATER SYSTEM | 60 | 0 |
| WITHROW WATER WORKS | 60 | 2 |
| APPLEWAY TRAILER COURT | 54 | 0 |
| COLUMBIA SPRINGS ESTATES | 54 | 0 |
| JOHNSON CREEK WATER USERS ASSN | 48 | 2 |
| METHOW WATER SYSTEM INC | 45 | 0 |
| RIVERWOOD WATER SYSTEM | 43 | 0 |
| TWIN LAKES HUD | 42 | 9 |
| ELM TREE WATER & SEWER ASSN | 38 | 0 |
| MANY LAKES MOBILE HOME PARK | 37 | 0 |
| Valley View Estates Water System | 28 | 0 |
| TWIN PINES MOBILE HOME PARK | 25 | 0 |
| AZWELL ORCHARDS | 7 | 3 |
TRI Facilities (1)
| # | Facility | Total Releases |
|---|---|---|
| 1 | US Cbp Oroville Port of Entry WA0021 | 123 lbs |
Superfund Sites (1)
| Site Name | Status | HRS Score |
|---|---|---|
| Silver Mountain Mine | Deleted NPL Site | 29.98 |
Cities in Okanogan (15)
Frequently Asked Questions
What is the environmental risk level in Okanogan, Washington? ▼
Are there Superfund sites in Okanogan? ▼
How many toxic release facilities are in Okanogan? ▼
What is the air quality in Okanogan? ▼
Is the drinking water safe in Okanogan? ▼
What environmental agencies cover Okanogan? ▼
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.