COMPLETION OF IN-SITU THERMAL REMEDIATION OF PAHs, PCP AND DIOXINS AT A FORMER WOOD TREATMENT FACILITY

The largest in-situ thermal conduction heating project ever undertaken at a wood treatment site was completed in March 2006. The site was a former utility pole treatment facility that Southern California Edison (SCE) operated from 1922 to 1957. The subsurface soils were contaminated primarily with polycyclic aromatic hydrocarbons (PAHs), pentachlorophenol (PCP), and polychlorinated dibenzodioxins and furans (PCDD/Fs), with soil treatment standards of 0.065 mg/kg Benzo(a)Pyrene Equivalents (B(a)P-E), 2.5 mg/kg PCP, and 1.0 µg/kg PCDD/Fs, expressed as 2,3,7,8-Tetrachlorodibenzodioxin (TCDD) Toxic Equivalents (TEQ), respectively. A feasibility study led to the selection of TerraTherm’s patented In-Situ Thermal Destruction (ISTD) technology, also known as In-Situ Thermal Desorption, which utilizes simultaneous application of thermal conduction heating and vacuum to treat contaminated soil without excavation. The applied heat volatilizes organic contaminants within the soil, enabling them to be carried in the vapor stream toward heater-vacuum wells.