Bioremediation of Bunker C-Contaminated Soils at Weyerhaeuser Company's Longview, Washington, Integrated Pulp and Paper Complex, 1992 Environmental Conference Proceedings

Due to an emerging state toxics clean-up initiative called the Model Toxics Control Act (MTCA) and internal housekeeping policies, Weyerhaeuser Company, Longview, Washington, realized a need to more carefully manage hydrocarbon contamination in the soil around its petroleum storage tank farm. The contamination of greatest concern was that from historic overflows of an oil/water separator system associated with a 100,000 gallon Bunker C (Residual Fuel Oil) storage tank.

Weyerhaeuser chose bioremediation, after also considering off-site land disposal of contaminated soil because of waste minimization, and long-term liability and cost avoidance considerations. Bioremediation, Inc. was selected to complete the clean-up project, which took place from January through September of 1991.

Bunker C is perhaps the most recalcitrant of the petroleum hydrocarbons for bioremediation. The alkanes, alkylaromatics, and aromatics above C22 have low toxicity, but their physical characteristics, including low water solubility and their solid state at the ideal physiological temperature of 35 C disfavor biodegradation. This inherent disfavor, in addition to specific soil and other conditions at an industrial site, dictate special efforts to track and achieve acceptable degradation rates.