Why the technology was selected:
Monitored natural attenuation was selected as the groundwater remedy, because contaminant concentrations in groundwater barely exceeded the MCL.

Date implemented:
December 19, 2001

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies

Why the technology was selected:
SVE was selected, because soil samples collected beneath the facility floor slab failed Synthetic Precipitation Leaching Procedure testing. Contaminated soils were permeable (sand) and located beneath the facility floor of an operating drycleaning facility. SVE is an effective technology for removing VOCs from permeable unsaturated sediments.

Date implemented:
December 19, 2001

Final remediation design:
Two vertical 4-inch diameter Schedule 40 PVC vapor extraction wells were installed beneath the facility floor slab, screened from 1-3.5 ft bgs (0.020 slotted screen). Five passive vapor inlet wells were installed (2-inch diameter Schedule 40 PVC), screened 1-3.5 ft bgs with 0.020 slotted sceen. Three of the vapor inlet wells were installed beneath the facility floor slab, and one was installed outside the service door of the facility. Piping from the vapor extraction wells was routed to the ceiling of the facility and out the wall to the treatment compound. The remedial system is skid mounted. The system is powered by a 3 HP regenerative blower. Vapor treatment: two 200 lb. GAC vessels. The system has a 40-gallon moisture separtor. The design flow rate is 15 cfm, with design blower vacuums of 40-53 inches.

Results to date:
System was operated at 42-45 inches of vacuum. In March 2004, an additional vapor recovery well was installed adjacent to the drycleaning machine. A compliance inspection found that there were problems with the operation of the drycleaning separator water treatment unit. Operation of the SVE system was discontinued on October 13, 2004. Confirmatory soil sampling showed that contaminant concentrations in the soil were below cleanup target levels. An estimated 4.86 pounds of VOCs (PCE) was recovered by the system.

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies

Date implemented:
December 19, 2001

Final remediation design:
Two vertical 4-inch diameter Schedule 40 PVC vapor extraction wells were installed beneath the facility floor slab, screened from 1-3.5 ft bgs (0.020 slotted screen). Five passive vapor inlet wells were installed (2-inch diameter Schedule 40 PVC), screened 1-3.5 ft bgs with 0.020 slotted sceen. Three of the vapor inlet wells were installed beneath the facility floor slab, and one was installed outside the service door of the facility. Piping from the vapor extraction wells was routed to the ceiling of the facility and out the wall to the treatment compound. The remedial system is skid mounted. The system is powered by a 3 HP regenerative blower. Vapor treatment: two 200 lb. GAC vessels. The system has a 40-gallon moisture separtor. The design flow rate is 15 cfm, with design blower vacuums of 40-53 inches.

Results to date:
System was operated at 42-45 inches of vacuum. In March 2004, an additional vapor recovery well was installed adjacent to the drycleaning machine. A compliance inspection found that there were problems with the operation of the drycleaning separator water treatment unit. Operation of the SVE system was discontinued on October 13, 2004. Confirmatory soil sampling showed that contaminant concentrations in the soil were below cleanup target levels. An estimated 4.86 pounds of VOCs (PCE) was recovered by the system.

Next Steps:
A Site Rehabilitation Completion Order will be issued for this site.

Cost to Design and Implement:
$84,400 for all technologies