JV Task 47-Demonstration of Vacuum-Enhanced Recovery and Feasibility of Permeable Treatment Barriers for Site Remediation at Hazen

The Energy and Environmental Research Center (EERC) conducted a demonstration of a vacuum-enhanced recovery and feasibility of permeable treatment barriers for soil and groundwater remediation at an Independent Oil (Former Star Mart) site in Hazen, North Dakota. A total of 62,584 lb (28,388) of contaminant was recovered from impacted soils and groundwater. The mass of recovered contaminant equals approximately 10,116 gallons of product. Groundwater quality monitoring confirmed the continuing contaminants of concern (COC) reduction trend in most monitoring wells and an average benzene reduction of 85% within the entire impacted area since remediation system start-up. A comparison of mass balance estimates for the extraction system with biodegradation stoichiometry using the assimilative capacity of the groundwater indicates that in situ natural attenuation processes became a dominant factor in reducing COCs and that improved site conditions justified termination of corrective action. The unit cost of contaminant recovery was $15. 26/lb ($33.65/kg). If in situ degradation resulting from oxygen delivery is considered, the cost would be $12.62/b ($27.82/kg) of contaminant recovered or degraded