A study was conducted at a contaminated site within the Watervliet Arsenal in New York State to assess the feasibility of bioremediation for the treatment of soils affected by PAHs and petroleum hydrocarbons. Indigenous organisms were determined to be able to aerobically and anaerobically degrade PAHs, and a demonstration of total petroleum hydrocarbon (TPH) and PAH biodegradation in soil slurries was conducted. The Microtox bioassay was used to determine soil toxicity before and after treatment. This paper describes the protocols of the microcosm experiment and the aerobic soil column study. Although both aerobic and anaerobic PAH degraders were present at the site, aerobic processes were found to be more efficient than anaerobic processes. The soil column data indicate that in situ landfarming would result in significant reductions in both PAH and TPH concentrations at the site.