TASKS

• Conducted in-situ surfactant flushing to demonstrate the removal of free phase and residual No. 2 heating oil using low concentration surfactant.
• Free product removal efficiency, measured in gallons per day, as compared to the current dual phase extraction, was greatly increased by the SESR technology (as great as 634%). An estimated total of 6395 gallons of free product were removed during the SESR implementation.
• Free product thickness in the SESR system wells, including 8 recovery wells and 4 injection wells, was significantly decreased or completely eliminated.
• Soil contaminant concentrations were decreased by an average of 70.1 percent based on soil core sample analyses. In areas where the flow was not as efficient, the decrease was 64.4 percent. In the center of the cell, along hydraulically efficient flow paths, the soil concentrations were decreased by as much as 75.7 percent.
• Groundwater concentrations measured at the finish of the SESR implementation, were apparently decreased due to the SESR remediation. It is assumed that the concentrations will rebound since free product completely surrounds the remediation cell and will slowly migrate back into the remediation cell area.
• The remaining surfactant concentration measured in the wells was less than 2 mg/l. This is significantly less than 1% of the original concentration injected.
• Fluorescein was used as conservative tracer. The fluorescein capture results (109%) indicated that, in effect, the entire volume of tracer injected was recovered. A significant volume of free product (650 gallons) was also recovered during the tracer test because of the efficiency of the injection/recovery system employed by Surbec.