WA DOT Signals Maintenance

Facility Site ID: 60549963 Cleanup Site ID: 9862

  • Site Status

  • No Further Action

Status Update

Ecology held a comment period  from July 19, 2019-August 19, 2019 to delist the Site from the Hazardous Sites List. This Site is now delisted from the Hazardous Sites List.

Site Background

A release of petroleum hydrocarbons to soil at the Site was reported to Ecology in 1991, when three 5,000-gallon capacity underground storage tanks (USTs) were upgraded. The laboratory analysis indicated that soil surrounding the USTs was contaminated with petroleum.

Cleanup Activities

The Washington State Department of Transportation conducted a cleanup action during the UST removal in 2015 that included:

• Excavation of the three USTs and disposal of 562 tons of contaminated soil at a permitted facility;
• Collection of five soil samples at the bottom and sidewalls of the excavation to confirm removal of all contaminated soil. The results from these samples indicated contaminated soil was removed; groundwater was not sampled during the tank removal activities.

An Ecology contractor performed a Supplemental Site Investigation in 2017 to further evaluate the status of the contamination in soil and to assess if groundwater had been impacted. The activities included the installation of ten soil borings for soil and groundwater sampling within the former UST excavation and vicinity. The laboratory results for soil and groundwater did not exceed state cleanup standards. The Supplemental Site Investigation confirmed that the concentrations of petroleum contaminants at the Site do not pose a threat to human health and the environment.
Legal 2
Document Title Document Date Document Type
WA DOT Signals Maintenance - No Further Action Letter 8/27/2019 NFA Letter – non-VCP
WA DOT Signals Maintenance - RCU Status Update 3/4/2013 Early Notice Letter
Leaking Underground Storage Tank 1
Document Title Document Date Document Type
WA DOT Signals Maintenance - UST Removal & Site Characterization Report 8/7/2015 LUST Site Characterization Report
Public Information 1
Document Title Document Date Document Type
WA DOT Signals Maintenance - Delisting Fact Sheet 7/19/2019 Fact Sheet\Public Notices
Technical Reports 4
Document Title Document Date Document Type
WA DOT Signals Maintenance - Draft Supplemental Site Investigation Report 1/16/2019 Remedial Investigation Report
WA DOT Signals Maintenance - Site Hazard Assessment 8/21/2015 Site Hazard Assessment Report
WA DOT Signals Maintenance - Rank Notification Letter 7/1/2015 Site Specific Administrative Document - other (Administrative correspondence)
WA DOT Signals Maintenance - SHA Notification Letter 9/26/2014 Site Specific Administrative Document - other (Administrative correspondence)
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

  • Northwest Regional Office
    15700 Dayton Ave N
    Shoreline, 98133
    Please schedule an appointment to view print documents at this location.
  • Seattle Public Library - Beacon Hill Branch
    2821 Beacon Ave S
    Seattle, 98144
    This location may only have print documents available during open comment periods.

Contaminants 4

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Non-Halogenated Organics - Benzene RB B
Non-Halogenated Organics - Petroleum-Diesel RB B
Non-Halogenated Organics - Petroleum-Gasoline RB B
Non-Halogenated Organics - Petroleum-Other RB 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.