In-Situ Soil Washing

Recognizing the parallels between profitably recovering oil from oil reservoirs and cost-efficiently removing contaminants from soils, Surtek has the capabilities to apply enhanced oil recovery technologies to hazardous waste site cleanup. Examples of potential applications are as follow:

• Removal of hydrocarbons resulting from surface (as in a refinery) or subsurface (as in a leaking underground storage tank) contamination in contact with an aquifer.
• Restoration of creosote or wood treatment sites
• Recovery of inorganic constituents in waste streams that have percolated down to groundwater sources.

Careful geologic description of the area of interest will be required do insure that good communication will exist between injection and production wells or trenches. Although many of the subsurface contaminant recovery applications may be in shallow, relatively unconfined sections of soil or bedrock, the use of enhanced oil recovery technology will still be feasible.

Surtek has evaluated the use of surfactants in combination with polymers and alkaline agents to remove NAPL from contaminated soil. Examples of our work are:

• Project Team member for writing the "Surfactant and Co-Solvent Flushing Best Practices Manual" for the Department of Defense, Advance Technology Demonstration Facility. Project Team members are CH2M HILL, Queen's University Ontario, and Surtek. This manual provides a state-of-the-art review of surfactant and co-solvent flushing, with particular emphasis on a critical review of 16 recently completed field pilot tests.
• The largest site DNAPL demonstration of surfactant-enhanced recovery, in which 24,000 gallons of creosote oil was recovered and total creosote oil was reduced by 93% at the Laramie Tie Treating Site in Wyoming.
• Laboratory demonstration of JP-4 jet fuel removal from contaminated soil at March Air Force Base in California using state-of-the-art in-situ soil washing technology.
• Laboratory design for in-situ surfactant removal of 65% of contaminating hydraulic oil in soil beneath an Extruder Plant in Florida.

This photo shows cored soil from a railroad tie treating plant after water flooding and after surfactant soil washing.