The port is currently updating a Remedial Investigation/Feasibility Study (RI/FS) for Terminal 30 under a Washington State Department of Ecology Agreed Order (AO). Terminal 30 is located east of Harbor Island and along the East Waterway. The RI summarizes more than 20-years of environmental investigations and interim actions performed at T-30, and describes the nature and extent of contamination in soil and groundwater. The FS evaluates various cleanup alternatives or remedies to protect human health and the environment.
The draft RI/FS was submitted to the Washington State Department of Ecology (Ecology) in September 2012 for agency review and comment. Following revision, the RI/FS will be available for public review and Ecology will accept comments. It is anticipated that the public comment period for the RI/FS will be in late 2012.
Following completion of the RI/FS, the port and Ecology will negotiate a plan to remove, contain, or treat contaminated soil and groundwater at T-30. The plan will be described in a draft Cleanup Action Plan (CAP), which also will be available for public review and comment.
Current Operations at Terminal 30?
Terminal 30 is a 31-acre container terminal located at 2431 E. Marginal Way that provides a Seattle base for a major shipping line. Containerized freight is transferred between ships, trucks, and temporary terminal storage using a series of rail-mounted overhead cranes and forklifts.
The port acquired the property from Chevron in 1985 and developed it as a container terminal, although the terminal was converted for use as a cruise ship facility between 1999 and 2008.
How was Terminal 30 Contaminated?
As early as 1905, the Standard Oil Company (now Chevron) operated a bulk petroleum handling and storage terminal on portions of T-30 where fuels including gasoline, diesel, and heating oil were stored in numerous above-ground tanks. The operations released petroleum-related compounds that resulted in the accumulation of free-phase petroleum in the subsurface and contamination of soil and groundwater.
Historic Cleanup Efforts
Environmental investigations and remediation at T-30 began in the early 1980s with Chevron’s discovery of petroleum contamination in soil and groundwater. The chemicals of concern include gasoline, diesel, and heavy oil range petroleum hydrocarbons; benzene, toluene, ethylbenzene, and xylene compounds (BTEX), and polyaromatic hydrocarbons (PAHs).
Nearly three decades of work by Chevron and the port have included considerable study and interim actions:
- Port and Ecology enter into Agreed Order (AO) for RI/FS in 1991
- Installation of a product recovery system that removed more than 171,000 gallons of product by the early 1990s
- Excavation and offsite disposal of more than 24,000 cubic yards of petroleum-impacted soil
- Construction of site-wide 12 to 16-inch thick asphalt cap
- Oxygen Release Compound injection in MW-42 area
- Installation of more than 100 monitoring and recovery wells
- Numerous technical studies and reports
- Completion of the initial RI/FS in 1998
- Installation of sheetpile wall and stormwater system in 2008-2009
- Continuation of monitoring and product recovery during the 2000s
- Additional Data Report, Disproportionate Cost Analysis, and proposed remedy in 2008
The remedial actions were performed with Ecology oversight under the auspices of the 1991 AO at a cost of approximately $20,000,000 and, have resulted in significant reductions in contaminant mass and risk. Concurrently, the site has been redeveloped from a bulk fuel facility into a busy shipping terminal that is an integral part of the Seattle shipping industry.
The mass of contamination at T-30 has been reduced by recovering and removing more than 170,000 gallons of free-phase petroleum over 20 years, excavation of contaminated soil during site redevelopment, plus natural degradation processes. The 2012 RI/FS identifies and evaluates applicable remedies to address the remaining contamination at T-30. The selected remedy will be described in the CAP and will be based on information and technical analyses performed for the RI/FS, and consideration of public comments and community concerns.