The gasification of coal and crude oil was a widespread means of producing medium- and high-Btu gas for much of the last two centuries in the United States. Many of these plants disposed of process wastes and less-valuable by-products onsite, thereby contaminating the soil with coal-tar waste, light oils, napthalene, and other similar materials. Polynuclear aromatic hydrocarbons (PAHS) are components of coal-tar wastes and other wastes that remain at many of these manufactured-gas plants sites. Institute of Gas Technology (IGT) is conducting research primarily in biodegradation, utilizing microoganisms for degrading contaminants so that the by-products, as well as the end products (mainly water and CO2), do not pose any environmental concerns. The goal is to enhance bioremediation by accelerating the degradation of multi-ring (2 to 6 ring) PAHs to environmentally acceptable products.