Project Description

URS completed the removal of five abandoned USTs at this former Dow Chemical facility. The tanks were each 30 ft in length and were approximately 12,000 gallon capacity. The tanks were partially filled with paints and coatings wastes and sludges and were backfilled with soils and concrete in the 1970s in an attempt to properly “close” the tanks in-place. Based upon sample analysis, the tank contents were RCRA hazardous waste by characteristic and were contributing to on going contamination to groundwater.
URS selected an in-situ oxidation chemical, BIOX, to treat the tank contents in- situ, to reduce VOC levels and eliminate their RCRA waste characteristics. The BIOX treatment involved injection of a chemical oxidizer into the VOC-laden tank fill material. A pilot test indicated that in-situ treatment was successful in reducing the VOC content of the tanks greater than 90% for most VOC compounds, and below 500 mg/kg VOCs, which resulted in elimination of the RCRA characteristics. Although the VOC levels were reduced significantly, the treatment was not sufficient to achieve the non-detect VOC levels required by the NYDEC for in-place closure. The remedial alternative selected by Dow was in-situ treatment of the remaining tanks and complete removal of the tanks and their contents. The in-situ treatment technology resulted in an estimated cost savings of $250,000 to Dow because of the ability to dispose the majority of the tank wastes at a non-hazardous waste disposal facility, relative to offsite incineration, which was the likely disposal option for the untreated high VOC tank materials.