Remediation Status: Site closed

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

Why the technology was selected:
Due to low contaminant levels in soil and groundwater, monitored natural attenutation was initially chosen as the remedy at the site. After two and one-half years of monitoring and no decline in contaminant concentrations in groundwater, the decision was made to conduct an active soil gas survey to evaluate the mass of VOCs present in the unsaturated zone in the contaminant source area. Four vapor monitoring points were installed (1.25-inch diameter PVC, screened 5-10 ft BLS). Two of the vapor monitoring points were installed beneath the facility floor slab and two were installed outside the facility (one outside service door and the other one on the side of the faciliy). A portable regenerative blower was run at 12-72 cfm to recovery vapor samples from each vapor monitoring point for a period of one hour for each sampling point. Soil gas samples were monitored with a PID and at the end of each sampling period, a soil gas sample was collected for fixed laboratory analysis. Fixed laboratory analysis of these samples found PCE in concentrations ranging from 8.2 to 25 mg/cubic meter. The decision was made to install a SVE system at the site.

Why the technology was selected:
Soil vapor extraction was chosen to address contamination in the unsaturated zone because it is an effective technology for removing VOCs in permeable unsaturated sediments.

Date implemented:
SVE system: September 24, 2004

Date completed:
July 1, 2005 (~ 8 months of operation)

Final remediation design:
One two-inch diameter Schedule 40 PVC vapor recovery well installed beneath the facility floor slab (screened 2-12 ft BLS). System powered by 1.5 HP Ametek Rotron regenerative blower. Off gas treated by 200 lb. G.A.C. unit.

System run at 43 scfm with 28 inches applied vacuum.

Results to date:
The SVE system was shut down on July 1, 2005. Groundwater monitoring continued for another year. Groundwater cleanup target levels were achieved in early 2006.

Next Steps:
The site has achieved No Further Action status. A Site Rehabilitation Completion Order was issued for the site on December 14, 2006.

Cost to Design and Implement:
$65,800 (includes active soil gas survey)