Land treatment of contaminated soil from wood-treating sites

Four fanner wood-treating Superfund sites located in the State of Montana are currently employing the use of biodegradation in engineered Land Treatment Units (LTUs) to achieve site remediation levels in contaminated soils for pentachlorophenol (PCP) and polynuclear aromatic hydrocarbon (PAH) compounds. The Superfund sites are the Libby Ground Water site, Libby, Montana, the BN Somers site, Somers, Montana, the Idaho Pole Company site, Bozeman, Montana and the Montana Pole and Treating Plant site, Butte, Montana. Contaminated soil from source areas at each site was excavated and placed in an LTU where the soil was irrigated, tilled and fertilized during the growing season from June through September. Remediation levels for soil, as required by the respective Records of Decision (RODs), have been achieved at all four of the sites. The remediation levels in soil for PCP range from 34 mg/kg to 48 mg/kg and the total carcinogenic PAH (cPAH or B2 PAH) levels range from 4.2 mg/kg to 59 mg/kg expressed as benzo(a)pyrene equivalents.