Urban Infill Condominium

Former Car Dealership – Seattle, WA

Canal Station was once the site of theproject_canalstation_lrg 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

Work Performed

  • Property transaction due diligenceCanal Station manhole
  • Regulatory negotiations – MTCA VCP
  • Permitting – construction stormwater, Metro discharge
  • Site cleanup design and redevelopment coordination
  • Construction plans and specifications
  • Construction oversight
  • Construction stormwater management

Value Added

  • 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
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