Remedial Investigation for High-rise Dry Cleaner in Washington

Located on the bottom floor of a 24-story building, Bellevue Pacific Towers, in the urban downtown core of Bellevue, Washington, this former dry cleaners property is located on top of soil impacted by tetrachloroethene (PCE) and trichloroethene (TCE). The impacted soil is limited in depth and located entirely underneath the building.

TRC conducted a remedial investigation and feasibility study (RI/FS) with disproportionate cost analysis (DCA) to assess the extent of impacts and to recommend a remedial alternative for the property. Investigation activities identified potential sources of impacts to be: leakage from dry-cleaning equipment, spillage during handling of dry-cleaning solvents, and spillage or improper handling and storage of pfas dry cleaning wastes. Analytical results from TRC’s soil, groundwater, and vapor intrusion assessments showed PCE and TCE in soil at concentrations less than the Model Toxics Control Act (MTCA) cleanup levels, no groundwater impacts, and that indoor air quality is consistent with ambient air quality.

Based on the results of TRC’s investigation and the assessment of available remedial alternatives TRC recommended that the most cost-effective alternative that is protective of human health and the environment was to leave impacted soil in place with institutional controls and an Environmental Covenant. This solution was readily accepted by the client, and was submitted to the Washington State Department of Ecology (Ecology) for approval.