WA DOT Union Gap District Site
Facility Site ID:
541
Cleanup Site ID:
4942
The site is located at the Washington State Department of Transportation’s (WSDOT) South Regional District Office which houses transportation-related administrative and maintenance buildings and includes utility and fleet vehicles. A release occurred from the underground storage tank (UST) system at the former fueling station situated on the facility property. The release was discovered in 1989 when the USTs were closed from service (decommissioned). Petroleum hydrocarbons were found in soil above Model Toxics Control Act (MTCA) cleanup levels (CULs).
During the UST decommissioning, an interim cleanup action was performed by excavating petroleum-contaminated soils (PCS). Some PCS was left in place due to avoid affecting the structural integrity of a nearby building. Typically, natural processes will occur if enough contaminated soil is removed and, in some cases, the soil and/or groundwater concentrations may decrease to levels below the MTCA CULs. Recent sampling of the soil did not show any petroleum hydrocarbons or its constituents such as benzene above their respective MTCA CULs. Groundwater was assessed earlier and for the equivalent period of one year. None of these chemicals were found to exceed their respective groundwater CULs.
Ecology issued a no further action letter and removed the site from the Hazardous Sites List.
During the UST decommissioning, an interim cleanup action was performed by excavating petroleum-contaminated soils (PCS). Some PCS was left in place due to avoid affecting the structural integrity of a nearby building. Typically, natural processes will occur if enough contaminated soil is removed and, in some cases, the soil and/or groundwater concentrations may decrease to levels below the MTCA CULs. Recent sampling of the soil did not show any petroleum hydrocarbons or its constituents such as benzene above their respective MTCA CULs. Groundwater was assessed earlier and for the equivalent period of one year. None of these chemicals were found to exceed their respective groundwater CULs.
Ecology issued a no further action letter and removed the site from the Hazardous Sites List.
Voluntary Cleanup Program
This site was cleaned up under our Voluntary Cleanup Program, which provides technical help to owners of contaminated sites.
Voluntary Cleanup Program customers pay fees to cover our costs for technical help and reviewing cleanup reports. Sites in this program must meet the same cleanup standards as the sites Ecology manages under legal orders.
Documents 9
Leaking Underground Storage Tank 1
| Document Title | Document Date | Document Type |
| WA DOT Union Gap - Site Assessment | 9/27/2023 | LUST - Site Assessment Report |
Public Information 2
| Document Title | Document Date | Document Type |
| WA DOT Union Gap District Site - delisting fact sheet in Spanish | 4/12/2024 | Fact Sheet\Public Notices |
| WA DOT Union Gap District Site - delisting fact sheet | 4/12/2024 | Fact Sheet\Public Notices |
Technical Reports 4
| Document Title | Document Date | Document Type |
| WA DOT Union Gap - Release Investigation Work Plan | 7/3/2023 | Site Specific Technical Document - other |
| WA DOT Union Gap - site clarification memo | 6/28/2022 | Site Specific Administrative Document - other (Administrative correspondence) |
| WA DOT Union Gap - Status Request | 2/11/2013 | Site Specific Administrative Document - other (Administrative correspondence) |
| WA DOT Union Gap - Soil Analysis Results | 10/25/1993 | Site Specific Technical Document - other |
Voluntary Cleanup Program 2
| Document Title | Document Date | Document Type |
| WA DOT Union Gap District Site - VCP CE0543 NFA | 12/19/2023 | VCP Administrative Document |
| WA DOT Union Gap - VCP acceptance letter and application forms | 6/30/2023 | VCP Administrative Document |
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.
Places to see print documents
-
Central Regional Office1250 W Alder StUnion Gap, 98903-0009Please schedule an appointment to view print documents at this location.
Contaminants 5
| Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
|---|---|---|---|---|---|---|
| Non-Halogenated Organics - Non-Halogenated Solvents | B | B | ||||
| Non-Halogenated Organics - Benzene | B | B | ||||
| Non-Halogenated Organics - Petroleum-Diesel | RB | B | ||||
| Non-Halogenated Organics - Petroleum-Gasoline | RB | B | ||||
| Non-Halogenated Organics - Petroleum-Other | B |
- S
- Suspected
- C
- Confirmed Above Cleanup Levels
- B
- Below Cleanup Levels
- RA
- Remediated-Above
- RB
- Remediated-Below
- R
- Remediated
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.