Service Station Decommissioning and Remediation

TRC assisted our Client to prepare this Chevron-branded gasoline station and minimart for redevelopment into a tunnel-type car wash. Redevelopment activities included an asbestos survey, and removing existing underground storage tanks (USTs) containing fuel and associated piping and dispensing equipment. The property is in a mixed-use area of commercial and residential properties in the South Hill area of the City of Puyallup, Washington.

Concurrent with redevelopment activities, TRC conducted an interim remedial action to address petroleum impacts to soil and groundwater. These impacts resulted from historical releases of petroleum products from USTs and associated components that were removed and replaced in 1987.

The interim remedial action removed the existing USTs and excavated the petroleum-impacted soil. In 2014, TRC supervised the removal of three USTs and associated equipment. Petroleum-impacted soil was excavated and disposed off-site at a landfill. To prepare for future contingent groundwater remediation actions, a low-cost infiltration gallery was installed before the excavation was backfilled. This system could be used for different remedial options including injection of chemical media, air sparging, ozone injection, or groundwater extraction.

Prior to remedial actions, TRC prepared and submitted an interim work plan and proposal to the responsible party for pre-approval. TRC then assisted the client with invoicing and cost-recovery from the responsible party.

The property was redeveloped as a tunnel-type carwash. Groundwater monitoring wells were reinstalled after redevelopment activities were completed and TRC continues quarterly groundwater monitoring.