The Institute of Gas Technology (IGT) has developed and demonstrated an integrated chemical/biological treatment (CBT) process to efficiently remediate soils and sludges contaminated with hazardous compounds such as polynuclear aromatic hydrocarbons (PAHs), volatile hydrocarbons (e.g., BTEX), and polychlorinated biphenyls (PCBs). Bench-scale studies as well as the field-scale tests show that the CBT process is effective in significantly enhancing the rate as well as the extent of degradation of these contaminants. In this paper, the results of bench-scale tests conducted with a variety of PAHs and a set of field-scale tests conducted with soils from a former manufactured gas plant (MGP) site (now a Superfund site) that contained coal-tar associated PAHs. The field tests results show that the chemically enhanced bioremediation using the CBT process results in up to 90% improvement over conventional bioremediation for total PAHs (2-6 ring compounds) degradation and over 100% improvement over conventional bioremediation for carcinogenic PAHs (4-6 ring compounds) degradation. In this paper, the preliminary results of the second field test being conducted using the contaminated soils from another MGP site are discussed.翩e