The objectives of this paper are to review information on abiotic and biotic interactions of PCBs in soil and sediment, and to suggest possible approaches to coupling enhanced availability to increased biodegradation. The authors are currently studying the biodegradation of PCBs found in a former drag strip soil in New York State that exemplifies the problems associated with bioavailability. The PCB concentration in this soil is roughly 500 mg/kg, and no longer resembles commercial Aroclor 1242(TM). Depletion of the di- and trichlorobiphenyls, probably due to the evaporation of these more volatile congeners, has resulted in a PCB congener profile that more closely resembles Aroclor 1248(TM). After 13 weeks, the soil in the top 3 cm of the test plot showed approximately 20% biodegradation of the PCB; after 18 weeks, approximately 25% of the PCB had degraded. The rate of biodegradation at the drag strip was about 50% of the rate seen in the laboratory experiments. However, even in optimized laboratory studies, approximately 50% of the total PCBs was unavailable to microbial degradation. The soil-bound, less-available PCB fraction is the focus of this discussion.