Remediation Status: In groundwater monitoring

Why the technology was selected:
In-situ biostimulation coupled with the abiotic remedy, zero valent iron (ZVI) was designed by Innovative Environmental Technologies Inc (IET) for the fourth injection event at the former Cottage Cleaners site due to the presence of reductive dechlorination that was occurring on the site. Reductive dechlorination was occurring at the site, but needed to be stimulated with both abiotic and biotic processes.

Date implemented:
Fall 2008- Biostimulation and ZVI

Final remediation design:
All four in-situ remedial material injections were conducted using direct push. The January 2006 and April 2006 chemical oxidation injections were composed of sodium permanganate and were conducted by Vironix. The treatment areas included inside the drycleaning facility (western portion) and outside the building on the western side of the building. The third injection was designed and implemented by Innovative Environmental Technologies, Inc (IET) and was a chemical oxidation in the inside points of the drycleaner. The chemical oxidation implemented was a combination of sodium persulfate and chelated iron that not only activated the persulfate, but also provided a source of electron acceptors. A solution of potassium permanganate was also used. The fourth injection event was also designed and conducted by IET. The fourth injection event was a full-scale remedial design using biostimulation and ZVI to stimulate reductive dechlorination that was occurring at the site. The remedial design included the use of hydrogen donors such as HRC, calcium proportionate, and yeast extract, nutrients and vitamins, an oxygen scavenger, and zero valent iron.

Results to date:
During the first two injections, excessive surfacing (daylighting) of the sodium permanganate occurred, indicating that the remedial material did not reach the contaminated area sufficiently. This problem was averted by switching remedial contractors as well as by using potassium permanganate instead of the less soluble sodium permanganate. The pre-remedial levels of groundwater contamination were (highest concentration in MW-3, west of the building, June 05) PCE: 7.190 mg/L TCE: 0.071 mg/L cis-1,2-DCE: 0.410 mg/L Vinyl Chloride: ND Post-Injection Groundwater Results (MW-4, south-west of building, March 08) PCE: 1.970 mg/L TCE: 0.018 mg/L Cis-1,2-DCE: 0.0485 mg/L Vinyl chloride: ND Four monitoring wells were in the targeted area for the biostimulation and ZVI remedial event, MW-1, MW-2, MW-3 and MW-4. MW-3 was destroyed in 2008 and was therefore not sampled. MW-3 was strongly affected by the chemical oxidation injections. The concentration of PCE decreased from 3.1 mg/L in January 2006, before the ISCO, to 0.05 mg/L in March 2007, after the ISCO events. MW-1 is located east of the former drycleaner and was affected by 2 direct push injection in 2008. The concentration of PCE decreased from 0.264 mg/L pre-injection to 0.127 mg/L in September 2009. TCE and cis-1,2-DCE concentrations remain below the state and EPA MCLs. MW-2 is located west of the former drycleaner and was strongly affected by both the chemical oxidation injections and the biostimulation and ZVI injection. Pre-oxidation concentrations were as follows in January 2006. PCE: 4.6 mg/L TCE: 0.081 mg/L Cis: 0.570 mg/L After the oxidation event in March 2007, the concentrations were as follows. PCE: 0.146 mg/L TCE: ND CIS: ND Rebounding occurred in MW-2 after the oxidation event, most likely to the mobilization of sorbed mass on the soil particles. The concentration of PCE increased to 1.77 mg/L in the March 2008 sampling event. After the injection of the organic hydrogen donors and ZVI, the concentrations of PCE, TCE, and cis-1,2-DCE decreased dramatically. The concentration of the contaminants of concern during the September 2009 sampling event are as follows: PCE: 0.00386 mg/L TCE: 0.00246 mg/L CIS: 0.107 mg/L VC: 0.144 mg/L MW-4 is located west of the former drycleaner and was affected by the biostimulation. MW-4 was not targeted during the ISCO injections. The concentrations were as follows pre-injection in March 2008. PCE: 1.97 mg/L TCE: 0.0189 mg/L CIS: 0.029 mg/L The concentrations after the injection event were as following in September 2009. PCE: 1.550 mg/L TCE: 0.0157 mg/L CIS: 0.120 mg/L The smaller decreases in MW-4 may be attributed to still positive ORP present in MW-4 during both post-injection monitoring events. The redox potential decreased from +581 mV to +48.9 mV, indicating that the remedial material affected the groundwater in the vicinity of MW-4.

Next Steps:
Bi-annual groundwater monitoring.

Cost to Design and Implement:
$246,537.00 (Interim action injections and groundwater monitoring designed and implemented by the consultant) $66,869.00 (designed and implemented by IET)

Why the technology was selected:
Chemical oxidation via potassium permanganate and sodium permanganate was conducted at the site first in order to oxidize the large concentrations of PCE present in the source area. A third chemical oxidation was conducted on the site with sodium permanganate, chelated iron, and sodium persulfate to stimulate biological activity after the chemical oxidation had occurred with the presence of sulfate.

Date implemented:
Winter 2006- Chemical Oxidation Spring 2006- Chemical Oxidation Winter 2006- Chemical Oxidation

Final remediation design:
All four in-situ remedial material injections were conducted using direct push. The January 2006 and April 2006 chemical oxidation injections were composed of sodium permanganate and were conducted by Vironix. The treatment areas included inside the drycleaning facility (western portion) and outside the building on the western side of the building. The third injection was designed and implemented by Innovative Environmental Technologies, Inc (IET) and was a chemical oxidation in the inside points of the drycleaner. The chemical oxidation implemented was a combination of sodium persulfate and chelated iron that not only activated the persulfate, but also provided a source of electron acceptors. A solution of potassium permanganate was also used. The fourth injection event was also designed and conducted by IET. The fourth injection event was a full-scale remedial design using biostimulation and ZVI to stimulate reductive dechlorination that was occurring at the site. The remedial design included the use of hydrogen donors such as HRC, calcium proportionate, and yeast extract, nutrients and vitamins, an oxygen scavenger, and zero valent iron.

Results to date:
During the first two injections, excessive surfacing (daylighting) of the sodium permanganate occurred, indicating that the remedial material did not reach the contaminated area sufficiently. This problem was averted by switching remedial contractors as well as by using potassium permanganate instead of the less soluble sodium permanganate. The pre-remedial levels of groundwater contamination were (highest concentration in MW-3, west of the building, June 05) PCE: 7.190 mg/L TCE: 0.071 mg/L cis-1,2-DCE: 0.410 mg/L Vinyl Chloride: ND Post-Injection Groundwater Results (MW-4, south-west of building, March 08) PCE: 1.970 mg/L TCE: 0.018 mg/L Cis-1,2-DCE: 0.0485 mg/L Vinyl chloride: ND Four monitoring wells were in the targeted area for the biostimulation and ZVI remedial event, MW-1, MW-2, MW-3 and MW-4. MW-3 was destroyed in 2008 and was therefore not sampled. MW-3 was strongly affected by the chemical oxidation injections. The concentration of PCE decreased from 3.1 mg/L in January 2006, before the ISCO, to 0.05 mg/L in March 2007, after the ISCO events. MW-1 is located east of the former drycleaner and was affected by 2 direct push injection in 2008. The concentration of PCE decreased from 0.264 mg/L pre-injection to 0.127 mg/L in September 2009. TCE and cis-1,2-DCE concentrations remain below the state and EPA MCLs. MW-2 is located west of the former drycleaner and was strongly affected by both the chemical oxidation injections and the biostimulation and ZVI injection. Pre-oxidation concentrations were as follows in January 2006. PCE: 4.6 mg/L TCE: 0.081 mg/L Cis: 0.570 mg/L After the oxidation event in March 2007, the concentrations were as follows. PCE: 0.146 mg/L TCE: ND CIS: ND Rebounding occurred in MW-2 after the oxidation event, most likely to the mobilization of sorbed mass on the soil particles. The concentration of PCE increased to 1.77 mg/L in the March 2008 sampling event. After the injection of the organic hydrogen donors and ZVI, the concentrations of PCE, TCE, and cis-1,2-DCE decreased dramatically. The concentration of the contaminants of concern during the September 2009 sampling event are as follows: PCE: 0.00386 mg/L TCE: 0.00246 mg/L CIS: 0.107 mg/L VC: 0.144 mg/L MW-4 is located west of the former drycleaner and was affected by the biostimulation. MW-4 was not targeted during the ISCO injections. The concentrations were as follows pre-injection in March 2008. PCE: 1.97 mg/L TCE: 0.0189 mg/L CIS: 0.029 mg/L The concentrations after the injection event were as following in September 2009. PCE: 1.550 mg/L TCE: 0.0157 mg/L CIS: 0.120 mg/L The smaller decreases in MW-4 may be attributed to still positive ORP present in MW-4 during both post-injection monitoring events. The redox potential decreased from +581 mV to +48.9 mV, indicating that the remedial material affected the groundwater in the vicinity of MW-4.

Next Steps:
Bi-annual groundwater monitoring.

Cost to Design and Implement:
$246,537.00 (Interim action injections and groundwater monitoring designed and implemented by the consultant) $66,869.00 (designed and implemented by IET)

Why the technology was selected:
In-situ biostimulation coupled with the abiotic remedy, zero valent iron (ZVI) was designed by Innovative Environmental Technologies Inc (IET) for the fourth injection event at the former Cottage Cleaners site due to the presence of reductive dechlorination that was occurring on the site. Reductive dechlorination was occurring at the site, but needed to be stimulated with both abiotic and biotic processes.

Date implemented:
Fall 2008- Biostimulation and ZVI

Final remediation design:
All four in-situ remedial material injections were conducted using direct push. The January 2006 and April 2006 chemical oxidation injections were composed of sodium permanganate and were conducted by Vironix. The treatment areas included inside the drycleaning facility (western portion) and outside the building on the western side of the building. The third injection was designed and implemented by Innovative Environmental Technologies, Inc (IET) and was a chemical oxidation in the inside points of the drycleaner. The chemical oxidation implemented was a combination of sodium persulfate and chelated iron that not only activated the persulfate, but also provided a source of electron acceptors. A solution of potassium permanganate was also used. The fourth injection event was also designed and conducted by IET. The fourth injection event was a full-scale remedial design using biostimulation and ZVI to stimulate reductive dechlorination that was occurring at the site. The remedial design included the use of hydrogen donors such as HRC, calcium proportionate, and yeast extract, nutrients and vitamins, an oxygen scavenger, and zero valent iron.

Results to date:
During the first two injections, excessive surfacing (daylighting) of the sodium permanganate occurred, indicating that the remedial material did not reach the contaminated area sufficiently. This problem was averted by switching remedial contractors as well as by using potassium permanganate instead of the less soluble sodium permanganate. The pre-remedial levels of groundwater contamination were (highest concentration in MW-3, west of the building, June 05) PCE: 7.190 mg/L TCE: 0.071 mg/L cis-1,2-DCE: 0.410 mg/L Vinyl Chloride: ND Post-Injection Groundwater Results (MW-4, south-west of building, March 08) PCE: 1.970 mg/L TCE: 0.018 mg/L Cis-1,2-DCE: 0.0485 mg/L Vinyl chloride: ND Four monitoring wells were in the targeted area for the biostimulation and ZVI remedial event, MW-1, MW-2, MW-3 and MW-4. MW-3 was destroyed in 2008 and was therefore not sampled. MW-3 was strongly affected by the chemical oxidation injections. The concentration of PCE decreased from 3.1 mg/L in January 2006, before the ISCO, to 0.05 mg/L in March 2007, after the ISCO events. MW-1 is located east of the former drycleaner and was affected by 2 direct push injection in 2008. The concentration of PCE decreased from 0.264 mg/L pre-injection to 0.127 mg/L in September 2009. TCE and cis-1,2-DCE concentrations remain below the state and EPA MCLs. MW-2 is located west of the former drycleaner and was strongly affected by both the chemical oxidation injections and the biostimulation and ZVI injection. Pre-oxidation concentrations were as follows in January 2006. PCE: 4.6 mg/L TCE: 0.081 mg/L Cis: 0.570 mg/L After the oxidation event in March 2007, the concentrations were as follows. PCE: 0.146 mg/L TCE: ND CIS: ND Rebounding occurred in MW-2 after the oxidation event, most likely to the mobilization of sorbed mass on the soil particles. The concentration of PCE increased to 1.77 mg/L in the March 2008 sampling event. After the injection of the organic hydrogen donors and ZVI, the concentrations of PCE, TCE, and cis-1,2-DCE decreased dramatically. The concentration of the contaminants of concern during the September 2009 sampling event are as follows: PCE: 0.00386 mg/L TCE: 0.00246 mg/L CIS: 0.107 mg/L VC: 0.144 mg/L MW-4 is located west of the former drycleaner and was affected by the biostimulation. MW-4 was not targeted during the ISCO injections. The concentrations were as follows pre-injection in March 2008. PCE: 1.97 mg/L TCE: 0.0189 mg/L CIS: 0.029 mg/L The concentrations after the injection event were as following in September 2009. PCE: 1.550 mg/L TCE: 0.0157 mg/L CIS: 0.120 mg/L The smaller decreases in MW-4 may be attributed to still positive ORP present in MW-4 during both post-injection monitoring events. The redox potential decreased from +581 mV to +48.9 mV, indicating that the remedial material affected the groundwater in the vicinity of MW-4.

Next Steps:
Bi-annual groundwater monitoring.

Cost to Design and Implement:
$246,537.00 (Interim action injections and groundwater monitoring designed and implemented by the consultant) $66,869.00 (designed and implemented by IET)