Owner: U.S. General Services Administration
- Environmental Site Assessment
- Soil and Groundwater Testing
- Hazardous and Contaminated Waste Remediation and Disposal
- Vapor Intrusion Study
- Health and Safety Plan
- Underground Storage Tank Closure
- Voluntary Cleanup Program (VCP)
EHSI was contracted by the U.S. General Services Administration (GSA) to provide site characterization, soil and groundwater remediation (including UST removals), and management guidance for a 39-acre commercial-industrial property located adjacent to the Duwamish Waterway in Seattle, Washington. The purpose of our work was to obtain a decision of No Further Action (NFA) from the Washington State Department of Ecology (Ecology) VCP. This Turnkey Remediation project managed by EHSI included regulatory compliance, extensive soil and groundwater characterization studies (Phase II ESAs), waste designation, hazardous material shipment preparation, and coordination of transport. Site remediation services included removal of an excess of 1,000 tons of contaminated soil and in-situ groundwater treatment. EHSI is currently serving as the regulatory liaison with Ecology on behalf of GSA for an NFA decision.
The Federal Center South Interim Soil Remediation focused on removal and disposal of chemically impacted soils from three areas across a parking lot and its surrounding environment. Contaminants found included diesel-range TPH in soil above regulatory cleanup levels. In addition, gasoline and heavy oil-range TPH and volatile organic compounds (VOCs) were detected in groundwater at concentrations above regulatory cleanup levels.
EHSI installed groundwater monitoring wells at four locations around the site perimeter. Remediation consisted of removal and disposal of TPH-contaminated soils from three separate excavation areas; stockpiling of contaminated soil removed from each excavation area on visqueen; stockpiling and separating of metal oil drums and cans from the medical/pharmaceutical waste on the contaminated soil stockpile; and collection of soil samples from sidewalls of each excavation, as well as from the stockpiled contaminated and “clean” overburden soils. EHSI performed analysis of overburden stockpile and excavation closure soil samples. Site restoration included backfilling and compaction of overburden and imported soil for each of the three excavations.