Remediation Status: Site closed

Why the technology was selected:
Biostimulation pilot study (HRC/potassium lactate) was implemented because anaerobic conditions were present in groundwater and some contaminant degradation had occurred (TCE was present). The site appeared to be carbon limited.

Date implemented:
Biostimulation pilot study: Injection occurred on September 9, 2004.

Final remediation design:
Two injection points were utilized for the biostimulation pilot study. Both of these injection points were installed in the service alley located behind the former drycleaning facility. HRC was injected continuously via direct push technology using a grout pump over the interval 11-20 ft BLS. Injection was 4lbs. of HRC per foot or a total of 36 lbs. of HRC. Ethyl lactate was injected in a 2-inch diameter PVC well screened 10-20 ft BLS. A total of 570 gallons of a 600 mg/l solution or 0.33 gallons of ethyl lactate were injected using a centrifugal pump. A bromide trace was using in both injectants.

Results to date:
The SVE system was deactivated on March 21, 2006. An estimated 2.4 lbs. of VOCs were recovered. No PCE daughter products other than TCE were detected in groundwater samples after the HRC/potassium lactate injection.

Next Steps:
The site has met the No Further Action criteria (without engineering or institutional controls) and a Site Rehabilitation Completion Order will be issued.

Cost to Design and Implement:
All technologies: Design: $63,100 Installation & Startup: $72,100

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:
SVE: November 22, 2004

Final remediation design:
The soil vapor extraction system employed three 4-inch diameter vertical PVC vapor extraction wells screened 3-10 ft BLS. The system was powered by a 15 HP regenerative blower. Vapor phase contaminants were treated with a 140 lb. G.A.C. vessel. The design flow rate for the system was 360 scfm. The estimated wellhead vacuum for each well was 7 inches of water-guage with a design radius of influence of 17 feet.

Results to date:
The SVE system was deactivated on March 21, 2006. An estimated 2.4 lbs. of VOCs were recovered. No PCE daughter products other than TCE were detected in groundwater samples after the HRC/potassium lactate injection.

Next Steps:
The site has met the No Further Action criteria (without engineering or institutional controls) and a Site Rehabilitation Completion Order will be issued.

Cost to Design and Implement:
All technologies: Design: $63,100 Installation & Startup: $72,100

Date implemented:
SVE: November 22, 2004

Final remediation design:
The soil vapor extraction system employed three 4-inch diameter vertical PVC vapor extraction wells screened 3-10 ft BLS. The system was powered by a 15 HP regenerative blower. Vapor phase contaminants were treated with a 140 lb. G.A.C. vessel. The design flow rate for the system was 360 scfm. The estimated wellhead vacuum for each well was 7 inches of water-guage with a design radius of influence of 17 feet.

Results to date:
The SVE system was deactivated on March 21, 2006. An estimated 2.4 lbs. of VOCs were recovered. No PCE daughter products other than TCE were detected in groundwater samples after the HRC/potassium lactate injection.

Next Steps:
The site has met the No Further Action criteria (without engineering or institutional controls) and a Site Rehabilitation Completion Order will be issued.

Cost to Design and Implement:
All technologies: Design: $63,100 Installation & Startup: $72,100