Remediation Status: In active remediation

Why the technology was selected:
Bioremediation, using potassium lactate as an amendment, was selected because anaerobic conditions exist in the aquifer and reductive dechlorination is an active process. PCE daughter products were present in groundwater. Bioremediation was used to polish low levels of VOCs in the shallow groundwater after the SVE system was decommissioned.

Date implemented:
First potassium lactate injection event: April 12, 2007. Second potassium lactate injection event: March 13-18, 2008.

Results to date:
SVE system was shut down in December 2006. The first potassium lactate injection event was conducted on April 12, 2007: Twenty gallons of 60% potassium lactate solution was mixed with 2,000 gallons of water and injected into each of the two SVE lateral vapor recovery wells at approximatley 3 gpm. The second potassium lactate injection event was conducted form March 13-18, 2008. A total of 100 gallons of 60% potasssium lactate solution was mixed with 5,500 gallons of water and injected into the two SVE lateral vapor extraction wells at approximatley 10 gpm. Groundwater monitoring conducted on February 11, 2008, prior to the second injection event found detectable concentrations of contaminants (20.8 ug/l PCE, 2.49 ug/l TCE, & 2.96 ug/l Cis 1,2-DCE) in only one monitor well. That well is installed beneath the facility floor slab in the contaminant source area. Groundwater monitoring was conducted in September 2008 and found the following in the source area monitor well: 12.6 ug/l PCE, 2.63 ug/l TCE and 0.9 ug/l cis 1,2-DCE. Dissolved oxygen 0.3 mg/l, ORP -296.1 millivolts, dissolved organic carbon 344 mg/l and total dissolved solids 1,620 mg/l. Clearly potassium lactate is reaching the source area monitor well but to date, there has been no marked increase in the production of PCE daughter products.

Next Steps:
Conduct post active remedial monitoring.

Cost to Design and Implement:
Bioremediation system design: $2,200 Bioremediation system implementation (includes two sampling events): $49,400

Why the technology was selected:
Soil vapor extraction was selected because it is an effective technology for removing VOCs from permeable unsaturated sediments.

Date implemented:
Soil vapor extraction system startup: February 25, 2003.

Final remediation design:
SVE System: Two 10 long vapor extraction wells, installed one foot beneath the facility floor slab via directionally drilling. The system is powered by a 3 HP rotary lobe Rotron blower. Startup flow rate was 36 scfm at 48 inces water column.

Results to date:
SVE system was shut down in December 2006. The first potassium lactate injection event was conducted on April 12, 2007: Twenty gallons of 60% potassium lactate solution was mixed with 2,000 gallons of water and injected into each of the two SVE lateral vapor recovery wells at approximatley 3 gpm. The second potassium lactate injection event was conducted form March 13-18, 2008. A total of 100 gallons of 60% potasssium lactate solution was mixed with 5,500 gallons of water and injected into the two SVE lateral vapor extraction wells at approximatley 10 gpm. Groundwater monitoring conducted on February 11, 2008, prior to the second injection event found detectable concentrations of contaminants (20.8 ug/l PCE, 2.49 ug/l TCE, & 2.96 ug/l Cis 1,2-DCE) in only one monitor well. That well is installed beneath the facility floor slab in the contaminant source area. Groundwater monitoring was conducted in September 2008 and found the following in the source area monitor well: 12.6 ug/l PCE, 2.63 ug/l TCE and 0.9 ug/l cis 1,2-DCE. Dissolved oxygen 0.3 mg/l, ORP -296.1 millivolts, dissolved organic carbon 344 mg/l and total dissolved solids 1,620 mg/l. Clearly potassium lactate is reaching the source area monitor well but to date, there has been no marked increase in the production of PCE daughter products.

Next Steps:
Conduct post active remedial monitoring.

Cost to Design and Implement:
SVE system design: $4,800 SVE system implementation: $51,800

Date implemented:
Soil vapor extraction system startup: February 25, 2003.

Final remediation design:
SVE System: Two 10 long vapor extraction wells, installed one foot beneath the facility floor slab via directionally drilling. The system is powered by a 3 HP rotary lobe Rotron blower. Startup flow rate was 36 scfm at 48 inces water column.

Results to date:
SVE system was shut down in December 2006. The first potassium lactate injection event was conducted on April 12, 2007: Twenty gallons of 60% potassium lactate solution was mixed with 2,000 gallons of water and injected into each of the two SVE lateral vapor recovery wells at approximatley 3 gpm. The second potassium lactate injection event was conducted form March 13-18, 2008. A total of 100 gallons of 60% potasssium lactate solution was mixed with 5,500 gallons of water and injected into the two SVE lateral vapor extraction wells at approximatley 10 gpm. Groundwater monitoring conducted on February 11, 2008, prior to the second injection event found detectable concentrations of contaminants (20.8 ug/l PCE, 2.49 ug/l TCE, & 2.96 ug/l Cis 1,2-DCE) in only one monitor well. That well is installed beneath the facility floor slab in the contaminant source area. Groundwater monitoring was conducted in September 2008 and found the following in the source area monitor well: 12.6 ug/l PCE, 2.63 ug/l TCE and 0.9 ug/l cis 1,2-DCE. Dissolved oxygen 0.3 mg/l, ORP -296.1 millivolts, dissolved organic carbon 344 mg/l and total dissolved solids 1,620 mg/l. Clearly potassium lactate is reaching the source area monitor well but to date, there has been no marked increase in the production of PCE daughter products.

Next Steps:
Conduct post active remedial monitoring.

Cost to Design and Implement:
SVE system design: $4,800 SVE system implementation: $51,800