Remediation Status: In active remediation

Why the technology was selected:
Monitored Natural Attenuation was chosen as the most appropriate solution for contaminants in groundwater.

Final remediation design:
Monitor attenuation of contaminant concentrations in groundwater.

Results to date:
Natural attenuation processes, controlled and consistently monitored, will be relied upon to degrade groundwater contaminants.

Next Steps:
Following 6 months of soil treatment, some soil will be re-used on the site for development, and the remainder will be disposed of at the appropriate facility. New wells will be installed once the shopping center redevelopment is completed. The groundwater will be monitored on a semi-annual basis to make sure the contaminants are degrading and to determine when appropriate stability/risk levels are achieved for site closure.

Cost to Design and Implement:
$80,000 for all technologies

Why the technology was selected:
Excavation of contaminated soils above vapor intrusion risk levels was chosen because 1)the shopping center was undergoing redevelopment, so soils were easily accessible and 2)vapor intrusion of chlorinated solvents into buildings on site was the pathway of concern.

Date implemented:
October 2005

Final remediation design:
Excavate, stockpile, treat and dispose of two source areas of contaminated soil to a depth of 6-16 feet bgs. One area is approximately 200 square feet and the other at 97 square feet.

Results to date:
Approximately 200 tons of source area contaminated soils above vapor intrustion risk levels were excavated and stockpiled onsite. Approximately 30 tons were at levels for subtitle D landfill disposal. The remaining 170 tons of soil are being treated onsite using vapor extraction for approximately 6 months until levels are within residential guidelines.

Next Steps:
Following 6 months of soil treatment, some soil will be re-used on the site for development, and the remainder will be disposed of at the appropriate facility. New wells will be installed once the shopping center redevelopment is completed. The groundwater will be monitored on a semi-annual basis to make sure the contaminants are degrading and to determine when appropriate stability/risk levels are achieved for site closure.

Cost to Design and Implement:
$80,000 for all technologies