Ex Situ Treatment of Soil Containing Hydraulic Oil and Diesel Fuel
Ex situ treatment of approximately 4,000 tons of soil impacted with hydraulic oil and diesel fuel at a former manufacturing facility in Georgetown, Ontario were treated using Adventus' TERRAMENDT technology. TERRAMEND™ effectively reduced contaminant concentrations to below the remedial goals in approximately 10 months of treatment.
Our goal was to achieve the remedial standard of 1,000 mg/kg for heavy oils and 100 mg/kg for gas/diesel in all sampling zones. At this site the client was particularly sensitive to treatment costs, and a very low cost approach was required. Due to this constraint treatment proceeded more slowly than otherwise possible; however remedial costs were kept very low.
Prior to application of TERRAMEND™, the soil was excavated and placed in a lined remediation cell to a thickness of approximately 2 feet. Soils were then tilled to ensure homogenization. Following cell preparation, TERRAMEND™ was applied using a site-specific aerobic protocol. The technology involved the addition of a blend of nutrients and soil conditioners designed to optimize the rate of microbial activity in the soil. The process also required the maintenance of soil moisture content at approximately 50% of the soil water holding capacity. Maintenance of the soil moisture content was accomplished through irrigation and tillage. A specialized deep rotary tiller was used to till to a depth of 2 feet; this also served to maintain an aerobic soil environment.
Active treatment of the soil occurred within the treatment cell for a period of approximately 9 months, from August 2000 to September 2001, with a 5 month inactive period from December 2000 to April 2001). During this period soil hydrocarbon concentrations were reduced by approximately 99%. All hydrocarbon concentrations were reduced to less than the established remedial standard of 1,000 mg/kg for heavy oils and 100 mg/kg for gas/diesel in all sampling zones. Following treatment, the mean concentration of heavy oil hydrocarbons was 67 mg/kg, while the mean concentration of the gas/diesel range hydrocarbons was 3 mg/kg.
The cost to treat soil at this site was US$20/ton of soil treated. This cost included all cell construction and treatment application costs and excluded excavation and final disposition of treated soil. Decommissioning of the treatment facilities and end-point analytical costs were also excluded.
Approximately 9 months, from August 2000 to September 2001, with a 5 month inactive period from December 2000 to April 2001.