Management of hydrocarbon-contaminated soil through bioremediation and landfill disposal at a remote location in Northern Canada

Abstract

Northern communities often have limited resources to resolve petroleum hydrocarbon (PHC) contamination. This project investigated an innovative approach for the management of diesel-contaminated soil in a remote community in Labrador. The soil was first treated in a passively aerated biopile to reduce the concentrations of mobile PHCs. The treated soil was then disposed of in the local landfill. Maximum total petroleum hydrocarbon (TPH) concentrations in soil, concentrations of PHCs with less than 16 carbons in soil, and TPH in leachate decreased during the 1 year field treatment. Microcosms incubated at 7 and 22 °C in the laboratory showed the potential for biodegradation of the PHCs. However, volatilization was likely the predominant PHC removal mechanism in the field. Disposal of treated soil to landfills has the advantage of transforming waste (i.e., soil) into a valued product (i.e., cover for the refuse). The development of risk-based guidelines for the disposal of PHC-contaminated soil into landfills in Canada appears to be needed and is discussed in this paper. Guidelines should be protective of the environment while prevent over-treatment of the soil, which may result in unnecessary spending and environmental impacts. The cost of the system tested was compared to that of treating soil in an off-site facility.