Phase II Environmental Assessment and Tank Removal, Vashon, WA; K2 Corporation
White Shield (WSI) provided K2 Corporation with a Phase II Environmental Site Assessment at their facility located on Vashon Island. WSI installed eleven borings at selected locations around the facility to investigate the potential for soil and/or groundwater contamination. All borings were advanced using a “Geoprobe” drill rig. The drill rig pushed a 2 inch “probe” to depths of approximately eight to twelve feet below ground surface. At each four foot interval, samples were collected for possible chemical analysis. The soil was visually examined for evidence of contamination and screened using an Organic Vapor Analyzer (OVA). Upon reaching groundwater a temporary 1-inch diameter well was placed in the boring and the water sampled for the location specific contaminants of concern. WSI also performed a GPR/magnetic survey to determine the exact location of a 300-gallon heating oil tank and to determine if a second tank was present. WSI’s Certified Site Assessor and a Certified Tank Decommissioner (Central Environmental Construction) cleaned, decommissioned, removed and disposed of the tank. WSI visually checked the soils beneath the tank and piping for signs of leakage, and collected five clearance samples from the sidewall and base of the tank excavation for diesel/heavy oil analysis. Approximately one hundred cubic yards of petroleum contaminated soil was excavated for disposal. Contaminated soil had migrated under the building at the site, and WSI is working with K2 and the Washington State Department of Ecology on a plan to address the future soil remediation.