UST Check → counties → Colorado → Douglas
Underground storage tanks & leak sites in Douglas County, CO
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.
247registered tank facilities
245open tanks
340closed tanks
157leak incidents on record
8cleanups still open
8 leak cleanups in
Douglas 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 |
|---|---|---|---|---|
| Douglas County School District- West Terminal | Castle Rock | 6 / 1 | Open UST(s) | CO250 |
| Alta #6104 | Castle Rock | 5 / 8 | Open UST(s) | CO520 |
| Alta #6116 | Parker | 4 / 4 | Open UST(s) | CO10873 |
| Castle Rock Self Service | Castle Rock | 4 / 1 | Open UST(s) | CO9257 |
| CST Metro LLC DBA Corner Store #666 | Castle Rock | 4 / 0 | Open UST(s) | CO3108 |
| Maverik Store #479 | Castle Rock | 4 / 0 | Open UST(s) | CO19365 |
| Twin Star Energy #531 | Castle Rock | 4 / 0 | Open UST(s) | CO15552 |
| CST Metro LLC DBA Corner Store #4137 | Parker | 4 / 0 | Open UST(s) | CO1299 |
Open leak cleanups — most recently reported
| Site | City | Reported | Substance | EPA record |
|---|---|---|---|---|
| Sky Ridge Hospital | Lone Tree | 2018-07-19 | — | CO13088 |
| Mini Stop | Parker | 2011-10-11 | — | CO11526 |
| Western Gas & Convenience Store | Castle Rock | 2009-12-12 | — | CO11023 |
| Sav-o-mat Inc | Castle Rock | 2009-10-22 | — | CO10972 |
| 7-Eleven #33040 | Highlands Ranch | 2004-10-19 | — | CO9633 |
| Circle K 1932 | Parker | 1998-10-13 | — | CO6916 |
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 247 registered facilities has an unknown number of unregistered ones.
- Open cleanups are the headline. 8 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