Former Car Dealership – Seattle, WA
Canal Station was once the site of the New Wilson Ford car dealership. Although car dealership activities led to certain environmental conditions (leaking UST and abandoned oil-water separator), the primary environmental concern at the site was a chlorinated solvent groundwater plume originating off-site.
The property was purchased to construct a mixed-use condominium building. The first phase was built on the clean parcel; the second phase was built on the parcel with impacted groundwater . CRETE principals developed the cleanup approach and negotiated a technical opinion letter with Ecology through the Voluntary Cleanup Program (VCP).
The groundwater remediation system consisted of a segregated under-slab groundwater collection system designed in conjunction with the building civil design and fully integrated into the development. Impacted groundwater is collected in a separate vault and is discharged to the sanitary sewer. A contingency for treatment of the groundwater was designed into the underground parking structure, but the contingency has not been triggered.
CRETE principals directed all aspects of the project, including:
- Phase I and Phase II site assessments
- Cleanup Action Plan preparation and review with Ecology
- Quarterly groundwater monitoring prior to construction
- Under-slab groundwater drainage system design
- Construction dewatering discharge authorizations from Metro King County and associated sampling and reporting
- Environmental cleanup construction oversight (i.e., removal of a leaking heating oil tank; removal of an oil-water separator containing dangerous waste)
- Excavation oversight and associated sampling
- Property transaction due diligence
- Regulatory negotiations – MTCA VCP
- Permitting – construction stormwater, Metro discharge
- Site cleanup design and redevelopment coordination
- Construction plans and specifications
- Construction oversight
- Construction stormwater management
- Segregated and sampled soil so that most was sent off site as clean material
- Negotiated a technical opinion letter with Ecology
- Fully integrated the groundwater extraction system with development
- Designed and negotiated discharge to the sanitary sewer to minimize costs