Although PCP has been classified as a priority pollutant, PCP-treated wood products are currently allowed to be disposed of as ordinary solid (non-hazardous) wastes in the US. Non-regulated disposal of these materials is allowed because PCP concentrations in extracts from PCP-treated products such as utility poles and crossarms, determined by the Toxicity Characteristic Leaching Procedure (TCLP) have been shown to be well below the regulatory level of 100 mg/L PCP. However, with increasing concerns regarding future liability associated with PCP-treated materials and with the reticence towards accepting large amounts of woody debris, the option of disposing by landfilling is rapidly disappearing. Also, disposal by incineration is expensive and not readily available. Therefore, alternate methods of disposal are needed. In laboratory experiments the white-rot fungus Trametes hirsuta has been shown to cause an 84% decrease in the PCP concentration of PCP-treated wood. After 4 weeks, the fate of 14C[PCP] in softwood chips inoculated with Trametes hirsuta was as follows: 27% was mineralized; 42.5% was non-extractable and bound to the chips; 23.5% was associated with fungal hyphae, and 6% was organic-extractable. Using biopile technology the use of Trametes hirsuta for the large-scale treatment of PCP-treated wood was evaluated on wood chips from southern pine and western red cedar utility poles that were treated with PCP. The effectiveness of the treatment was evaluated throughout the treatment period by assessing the PCP concentration in the chips and the toxicity of the chips using a submitochondrial particle assay. Fungal growth was assessed indirectly by measuring the ergosterol content of the chips throughout the treatment period.

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