UST Check → counties → Washington → King
Underground storage tanks & leak sites in King County, WA
Every figure below is from EPA UST Finder — the EPA-compiled national registry of state-reported underground storage tanks — county aggregates as published by EPA.
3,932registered tank facilities
2,118open tanks
10,413closed tanks
1,088leak incidents on record
1,041cleanups still open
1,041 leak cleanups in
King County are still open — the state has not closed the case.
An open cleanup near a property you're buying or lending on is a findable, checkable fact: it appears in a
per-address screen with distance and the registry record.
Largest registered facilities
By open-tank count, from the facility-level registry. Every fact is attributed to the EPA record (linked ID); something wrong — use the correction path in the footer and we'll fix or remove it promptly.
| Facility | City | Open / closed tanks | Status | EPA record |
|---|---|---|---|---|
| SOUTH BASE | Seattle | 13 / 17 | Open UST(s) | WA34128282 |
| METRO TRANSIT NORTH BASE | Shoreline | 10 / 0 | Open UST(s) | WA12321618 |
| KING COUNTY DEPT OF NATURAL RESOURCES SOLID W | Maple Valley | 9 / 12 | Open UST(s) | WA2020 |
| CENTRAL BASE MAINTENANCE FAC | Seattle | 9 / 0 | Open UST(s) | WA84856352 |
| RENTON PLANT | Renton | 8 / 35 | Open UST(s) | WA64745478 |
| EAST OPERATING BASE | Bellevue | 8 / 14 | Open UST(s) | WA18962661 |
| FUEL FARM | Auburn | 8 / 0 | Open UST(s) | WA88674989 |
| AVIATION FUEL STORAGE | Seattle | 8 / 0 | Open UST(s) | WA44648718 |
Open leak cleanups — most recently reported
| Site | City | Reported | Substance | EPA record |
|---|---|---|---|---|
| Tiki Car Wash | BELLEVUE | not reported | Non-Halogenated Solvents | WA5096 |
| 7-Eleven 22866 | TUKWILA | not reported | Benzene | WA8378 |
| Graphicolor Inc | SEATTLE | not reported | Petroleum-Other | WA5734 |
| BURIEN IMPORTS LTD | SEATTLE | not reported | Petroleum-Gasoline | WA8384 |
| Seattle Public Utilities Operations Ctr | SEATTLE | not reported | Petroleum-Other | WA5099 |
| 80 S Hudson St | SEATTLE | not reported | Benzene | WA8390 |
What this means if you're buying or lending here
- "Closed" ≠ clean. A closed tank was taken out of service per the registry — many were closed without soil testing, especially before the late 1990s.
- The registry is incomplete by design. Tanks removed before 1986 and most residential heating-oil tanks were never registered. A county with 3,932 registered facilities has an unknown number of unregistered ones.
- Open cleanups are the headline. 1,041 cases in this county are still open; contamination may still be under investigation or remediation — distance from a specific parcel is what matters, and that's a per-address question.
Screen a specific property
This page covers the county. A purchase or loan decision needs the registry around one address: registered tanks at the parcel, every facility within 500 and 1,500 ft, leak cleanups with status and distance — each line cited to the official record.
Screen an address — $49 How it worksThis is a screen of EPA-registered tank and leak records, not an environmental site assessment. State registries are incomplete by design: tanks removed before 1986 and most residential heating-oil tanks were never registered, so a clean screen cannot prove the absence of a tank. "Closed" means a tank was taken out of service per the registry — it does not certify that no contamination remains.
source: EPA UST Finder EPA data vintage 2024-12-04 computed 2026-06-12