On Site Bioremediation of Oil Contaminated Soil at a Southeaster Kraft Mill, 1996 Environmental Conference Proceedings

A Kraft Mill in the southeastern United States had previously used fuel oil as a secondary boiler fuel. The fuel was stored in a bulk storage tank in a diked area equipped with a sump to collect leakage and contaminated water. Over the years, the sump had become partially filled with oil-contaminated soil. Because the tank was no longer in service, the mill decided to remove the soil from the sump. On-site disposal of the untreated material in the mill’s landfill was not allowable under the mill’s current permit. The mill investigated the option of off-site disposal, as well as bioremediation in the mill’s on-site, permitted landfill. Upon approval from the state environmental agency, the mill began a program of removing the soil from the sump and spreading it in a isolated section of the landfill. The soil was mixed with biological sludge from the activated sludge plant to provide nutrients. Biological cultures selected for their ability to degrade hydrocarbons were added to enhance the clean-up process. The soil was tilled to provide aeration and watered periodically to maintain the desired moisture content. This paper presents the results of this process, outlines the procedures employed and discusses the benefits to the mill and the environment.