Date implemented:
7/17/01

Final remediation design:
A 0.5 - 2 % KMnO4 was injected into the perched water bearing zone, about 10-15 ft bgs using direct push technologies. The remediation was completed in a phased approach. Injections occurred four times over a one year period. A total of 837 pounds of KMnO4 was injected, which is equivalent to 9485 gallons of solution. Each phase included both on-site and off-site injections. The infections on site were completed around the three identified source areas on the site at a spacing of 15-20 ft. Off-site injections targeted the dissolved phase plume. Each injection point received injections at two depths: one approximately 5 ft from the bottom of the transmissive zone, and the other five to 10 ft above the first. The solution was injected at a rate of 1-5 gallons/minute, at a pressure of 15-25 psi. In addition to the permanganate injections, enhanced bioremediation was also employed at three source areas using a biological product called Cl-Out, which consists of freeze dried strains of naturally occurring bacteria that provides rapid, aerobic degradation of chlorinated compounds. Dextrose is added to “activate” the bacteria. These bacteria were injected in Februaru 2003 using a series of temporary injection points. The injection points were spaced 6-25 ft apart. Soil impacts were addressed through excavation along the sanitary sewer line, one of the only parts of the site not covered with asphalt. This unpaved part of the property was accumulating storm water and therefore covered with an impermeable cap. Underneath this cap, an SVE system was installed. The system consisted of a gallery of 6 vertical, 2-inch-diameter PVC wells, 3 feet deep, and 10 feet apart. The areas around the system were filled with pea gravel. The SVE system was operated for 2 months to remove any residual soil contamination in the area.

Results to date:
The highest pre-injection concentrations seen at the source wells were 3400 µg/L for PCE and 610 µg/L for TCE. Following the first KMnO4 injection, the concentrations in the source wells ranged from non-detect-79 µg/L for PCE and non-detect-74 µg/L for TCE. The TCE and PCE concentrations were noted to fluctuate across the non-source wells, but the concentrations were generally decreasing. At the downgradient wells, the plumes have remained stable, or had decreased. Following the Cl-Out injection in February, results in two source wells sampled in December 2003 showed PCE decreasing from 700 µg/L to 43 µg/L, and 130 µg/L to 26 µg/L. TCE in the two source wells decreased from 250 µg/L to 21 µg/L, and 140 µg/L to 8 µg/L.

Next Steps:
Monitoring will continue on a quarterly basis. The owner plans to apply for a conditional closure of the site. As of yet, no conditional closures made.

Why the technology was selected:
In-situ chemical oxidation (ISCO) was selected because it can oxidize DNAPLs, does not require expensive pump systems, can treat area without disturbing aboveground structures, and does not require excavation and disposal of contaminated soils. Potassium permanganate was specifically selected because it has been shown to be effective for chlorinated solvents; it does not react with carbonate and bicarbonate in soil; the reaction is not exothermic; and the reaction is not toxic to microbes in the soil.

Date implemented:
7/17/01

Final remediation design:
A 0.5 - 2 % KMnO4 was injected into the perched water bearing zone, about 10-15 ft bgs using direct push technologies. The remediation was completed in a phased approach. Injections occurred four times over a one year period. A total of 837 pounds of KMnO4 was injected, which is equivalent to 9485 gallons of solution. Each phase included both on-site and off-site injections. The infections on site were completed around the three identified source areas on the site at a spacing of 15-20 ft. Off-site injections targeted the dissolved phase plume. Each injection point received injections at two depths: one approximately 5 ft from the bottom of the transmissive zone, and the other five to 10 ft above the first. The solution was injected at a rate of 1-5 gallons/minute, at a pressure of 15-25 psi. In addition to the permanganate injections, enhanced bioremediation was also employed at three source areas using a biological product called Cl-Out, which consists of freeze dried strains of naturally occurring bacteria that provides rapid, aerobic degradation of chlorinated compounds. Dextrose is added to “activate” the bacteria. These bacteria were injected in Februaru 2003 using a series of temporary injection points. The injection points were spaced 6-25 ft apart. Soil impacts were addressed through excavation along the sanitary sewer line, one of the only parts of the site not covered with asphalt. This unpaved part of the property was accumulating storm water and therefore covered with an impermeable cap. Underneath this cap, an SVE system was installed. The system consisted of a gallery of 6 vertical, 2-inch-diameter PVC wells, 3 feet deep, and 10 feet apart. The areas around the system were filled with pea gravel. The SVE system was operated for 2 months to remove any residual soil contamination in the area.

Results to date:
The highest pre-injection concentrations seen at the source wells were 3400 µg/L for PCE and 610 µg/L for TCE. Following the first KMnO4 injection, the concentrations in the source wells ranged from non-detect-79 µg/L for PCE and non-detect-74 µg/L for TCE. The TCE and PCE concentrations were noted to fluctuate across the non-source wells, but the concentrations were generally decreasing. At the downgradient wells, the plumes have remained stable, or had decreased. Following the Cl-Out injection in February, results in two source wells sampled in December 2003 showed PCE decreasing from 700 µg/L to 43 µg/L, and 130 µg/L to 26 µg/L. TCE in the two source wells decreased from 250 µg/L to 21 µg/L, and 140 µg/L to 8 µg/L.

Next Steps:
Monitoring will continue on a quarterly basis. The owner plans to apply for a conditional closure of the site. As of yet, no conditional closures made.

Date implemented:
7/17/01

Final remediation design:
A 0.5 - 2 % KMnO4 was injected into the perched water bearing zone, about 10-15 ft bgs using direct push technologies. The remediation was completed in a phased approach. Injections occurred four times over a one year period. A total of 837 pounds of KMnO4 was injected, which is equivalent to 9485 gallons of solution. Each phase included both on-site and off-site injections. The infections on site were completed around the three identified source areas on the site at a spacing of 15-20 ft. Off-site injections targeted the dissolved phase plume. Each injection point received injections at two depths: one approximately 5 ft from the bottom of the transmissive zone, and the other five to 10 ft above the first. The solution was injected at a rate of 1-5 gallons/minute, at a pressure of 15-25 psi. In addition to the permanganate injections, enhanced bioremediation was also employed at three source areas using a biological product called Cl-Out, which consists of freeze dried strains of naturally occurring bacteria that provides rapid, aerobic degradation of chlorinated compounds. Dextrose is added to “activate” the bacteria. These bacteria were injected in Februaru 2003 using a series of temporary injection points. The injection points were spaced 6-25 ft apart. Soil impacts were addressed through excavation along the sanitary sewer line, one of the only parts of the site not covered with asphalt. This unpaved part of the property was accumulating storm water and therefore covered with an impermeable cap. Underneath this cap, an SVE system was installed. The system consisted of a gallery of 6 vertical, 2-inch-diameter PVC wells, 3 feet deep, and 10 feet apart. The areas around the system were filled with pea gravel. The SVE system was operated for 2 months to remove any residual soil contamination in the area.

Results to date:
The highest pre-injection concentrations seen at the source wells were 3400 µg/L for PCE and 610 µg/L for TCE. Following the first KMnO4 injection, the concentrations in the source wells ranged from non-detect-79 µg/L for PCE and non-detect-74 µg/L for TCE. The TCE and PCE concentrations were noted to fluctuate across the non-source wells, but the concentrations were generally decreasing. At the downgradient wells, the plumes have remained stable, or had decreased. Following the Cl-Out injection in February, results in two source wells sampled in December 2003 showed PCE decreasing from 700 µg/L to 43 µg/L, and 130 µg/L to 26 µg/L. TCE in the two source wells decreased from 250 µg/L to 21 µg/L, and 140 µg/L to 8 µg/L.

Next Steps:
Monitoring will continue on a quarterly basis. The owner plans to apply for a conditional closure of the site. As of yet, no conditional closures made.

Date implemented:
7/17/01

Final remediation design:
A 0.5 - 2 % KMnO4 was injected into the perched water bearing zone, about 10-15 ft bgs using direct push technologies. The remediation was completed in a phased approach. Injections occurred four times over a one year period. A total of 837 pounds of KMnO4 was injected, which is equivalent to 9485 gallons of solution. Each phase included both on-site and off-site injections. The infections on site were completed around the three identified source areas on the site at a spacing of 15-20 ft. Off-site injections targeted the dissolved phase plume. Each injection point received injections at two depths: one approximately 5 ft from the bottom of the transmissive zone, and the other five to 10 ft above the first. The solution was injected at a rate of 1-5 gallons/minute, at a pressure of 15-25 psi. In addition to the permanganate injections, enhanced bioremediation was also employed at three source areas using a biological product called Cl-Out, which consists of freeze dried strains of naturally occurring bacteria that provides rapid, aerobic degradation of chlorinated compounds. Dextrose is added to “activate” the bacteria. These bacteria were injected in Februaru 2003 using a series of temporary injection points. The injection points were spaced 6-25 ft apart. Soil impacts were addressed through excavation along the sanitary sewer line, one of the only parts of the site not covered with asphalt. This unpaved part of the property was accumulating storm water and therefore covered with an impermeable cap. Underneath this cap, an SVE system was installed. The system consisted of a gallery of 6 vertical, 2-inch-diameter PVC wells, 3 feet deep, and 10 feet apart. The areas around the system were filled with pea gravel. The SVE system was operated for 2 months to remove any residual soil contamination in the area.

Results to date:
The highest pre-injection concentrations seen at the source wells were 3400 µg/L for PCE and 610 µg/L for TCE. Following the first KMnO4 injection, the concentrations in the source wells ranged from non-detect-79 µg/L for PCE and non-detect-74 µg/L for TCE. The TCE and PCE concentrations were noted to fluctuate across the non-source wells, but the concentrations were generally decreasing. At the downgradient wells, the plumes have remained stable, or had decreased. Following the Cl-Out injection in February, results in two source wells sampled in December 2003 showed PCE decreasing from 700 µg/L to 43 µg/L, and 130 µg/L to 26 µg/L. TCE in the two source wells decreased from 250 µg/L to 21 µg/L, and 140 µg/L to 8 µg/L.

Next Steps:
Monitoring will continue on a quarterly basis. The owner plans to apply for a conditional closure of the site. As of yet, no conditional closures made.