Remediation Status: Site closed

Why the technology was selected:
Monitored natural attenuation was chosen as the groundwater remedy because reductive dechlorination was an active process, and it was believed that addressing soil contamination by excavation and soil vapor extraction would result in a large reduction in contaminant concentrations in groundwater.

Next Steps:
This site has met No Further Action conditions (without institutional and engineering controls). A Site Rehabilitation Completion Order will be issued for the site.

Cost to Design and Implement:
Design: $14,400 Excavation: $2,900 SVE Install & Startup: $54,200

Why the technology was selected:
Soil vapor extraction was selected because it is an effective technology for remediating permeable soils contaminated with VOCs.

Date implemented:
Soil Vapor Extraction: August 26, 2003

Final remediation design:
The soil vapor extraction system consisted of nine vapor extraction wells screened 1-5 feet below grade. Six of these wells were installed beneath the floor slab of the drycleaning facility and three of the wells were installed outside the back of the building that housed the drycleaning operation. The system is powered by a 10 HP Rotron regenerative blower. Design flow rate is 260 cfm A 3 HP Rotron regenerative blower was utilized for air injection. Off gas is treated via a 200 lb. G.A.C. vessel.

Results to date:
On April 10, 2002 approximately 7.3 cubic feet of soil was excavated from the area outside the service door of the facility. All nine (9) wells were utilized for vapor recovery for the first 36 days of operation of the SVE system. After that 4 wells were utilized for vapor recovery with 4 wells off and then the remaining 5 wells were used for vapor recoveyr wells with 4 wells off. Finally, air was injected into five wells and four wells were used for vapor recovery and then air injection wells were used for vapor recovery and air was injected into the wells that had been used for vapor recovery. This was done to increase wellhead vacuum, increase the system radius of influence, eliminate dead zones and to change change air flow paths to maximize system recovery and efficiency. The Soil vapor extraction system was turned off in June 2004 after ten months of operation. Confirmatory soil samples showed that soil has been remediated to below cleanup target levels. No contaminants have been detected in groundwater samples collected during the last two groundwater monitoring events conducted in 2009.

Next Steps:
This site has met No Further Action conditions (without institutional and engineering controls). A Site Rehabilitation Completion Order will be issued for the site.

Cost to Design and Implement:
Design: $14,400 Excavation: $2,900 SVE Install & Startup: $54,200

Date implemented:
Soil Vapor Extraction: August 26, 2003

Final remediation design:
The soil vapor extraction system consisted of nine vapor extraction wells screened 1-5 feet below grade. Six of these wells were installed beneath the floor slab of the drycleaning facility and three of the wells were installed outside the back of the building that housed the drycleaning operation. The system is powered by a 10 HP Rotron regenerative blower. Design flow rate is 260 cfm A 3 HP Rotron regenerative blower was utilized for air injection. Off gas is treated via a 200 lb. G.A.C. vessel.

Results to date:
On April 10, 2002 approximately 7.3 cubic feet of soil was excavated from the area outside the service door of the facility. All nine (9) wells were utilized for vapor recovery for the first 36 days of operation of the SVE system. After that 4 wells were utilized for vapor recovery with 4 wells off and then the remaining 5 wells were used for vapor recoveyr wells with 4 wells off. Finally, air was injected into five wells and four wells were used for vapor recovery and then air injection wells were used for vapor recovery and air was injected into the wells that had been used for vapor recovery. This was done to increase wellhead vacuum, increase the system radius of influence, eliminate dead zones and to change change air flow paths to maximize system recovery and efficiency. The Soil vapor extraction system was turned off in June 2004 after ten months of operation. Confirmatory soil samples showed that soil has been remediated to below cleanup target levels. No contaminants have been detected in groundwater samples collected during the last two groundwater monitoring events conducted in 2009.

Next Steps:
This site has met No Further Action conditions (without institutional and engineering controls). A Site Rehabilitation Completion Order will be issued for the site.

Cost to Design and Implement:
Design: $14,400 Excavation: $2,900 SVE Install & Startup: $54,200

Why the technology was selected:
Excavation was selected because there was a shallow groundwater table and contaminated soils were accessible.

Date implemented:
Excavation: April 10, 2002 Soil Vapor Extraction: August 26, 2003

Results to date:
On April 10, 2002 approximately 7.3 cubic feet of soil was excavated from the area outside the service door of the facility. All nine (9) wells were utilized for vapor recovery for the first 36 days of operation of the SVE system. After that 4 wells were utilized for vapor recovery with 4 wells off and then the remaining 5 wells were used for vapor recoveyr wells with 4 wells off. Finally, air was injected into five wells and four wells were used for vapor recovery and then air injection wells were used for vapor recovery and air was injected into the wells that had been used for vapor recovery. This was done to increase wellhead vacuum, increase the system radius of influence, eliminate dead zones and to change change air flow paths to maximize system recovery and efficiency. The Soil vapor extraction system was turned off in June 2004 after ten months of operation. Confirmatory soil samples showed that soil has been remediated to below cleanup target levels. No contaminants have been detected in groundwater samples collected during the last two groundwater monitoring events conducted in 2009.

Next Steps:
This site has met No Further Action conditions (without institutional and engineering controls). A Site Rehabilitation Completion Order will be issued for the site.

Cost to Design and Implement:
Design: $14,400 Excavation: $2,900 SVE Install & Startup: $54,200