In situ bioremediation - various additives
Blacks - In-situ bioremediation using sodium lactate followed by emulsified soybean oil. System includes three horizontal injection points beneath building footprint, a horizontal injection system in former source area, and several vertical injection wells between dry cleaner facility and adjacent apartment building.
Boone - In-situ bioremediation using corn syrup, Simple Green®, and vegetable oil.
- Twelve 4" injection wells and eight 2" pilot test monitoring wells installed to a depth of 18 ft.
Carousel - In situ bioremediation using BioRem H-10
Former 60 - In situ bioremediation using ethyl lactate injection/groundwater withdrawal and re-injection.
- A total of 110 gallons injected in a 1-2% solution.
Village Green - In situ bioremediation using ethyl lactate
- 12 injection points and 7 recovery wells installed in the source area for the bioremediation
- In dissolved phase portion, 4 shallow and 5 deep injection wells were installed.
- A total of 880 gallons of ethyl lactate were pumped into the 12 injection points above the source area.
Contacts: Varied by site
Blacks (Groundwater) cis-1,2-DCE - 39 mg/L; dichlorobenzenes - 0.003 mg/L; PCE - 8.7 mg/L; TCE - 10.4 mg/L; vinyl chloride 0.35 mg/L; xylenes 0.05 mg/L
(Soil) cis-1,2-DCE - 10.9 mg/kg; PCE - 1,100 mg/kg; TCE - 91.6 mg/kg; vinyl chloride - 0.14 mg/kg
Boone (Groundwater) 1,1-DCE - 2.7 µg/L; benzene - 32,100 µg/L; cis-1,2-DCE - 1780 µg/L; m-xylene - 16,300 µg/L; PCE - 89,800 µg/L; trans-1,2-DCE - 6.0 µg/L; TCE - 610 µg/L; vinyl chloride - 220 µg/L.
(Soil): cis-1,2-DCE - 156 µg/kg; lead - 151 mg/kg; m-xylene - 283 µg/kg; PCE - 6,090 mg/kg; trans-1-2-DCE - 13 µg/kg; TCE - 39 µg/kg
Carousel (Groundwater) PCE - up to 25,700 µg/L; (Soil) PCE - up to 7,000 mg/kg
Former 60 (Groundwater) 1,1-DCA - 8.6 µg/l; 1,1-DCE - 1,050 µg/l; benzene -150 µg/l; cis-1,2-DCE - 2,321 µg/l; MTBE - 29.5 µg/l; PCE - 6,820 µg/l; trans-1,2-DCE - 150 µg/l; TCE - 2,040 µg/l; vinyl chloride - 150 µg/l
(Soil): PCE - 1,800 µg/kg; TCE - 2.97 µg/kg
Village Green (Groundwater) cis-1,2-DCE - 8,550 µg/L; PCE - 27,300 µg/L; TCE - 7,900 µg/L; vinyl chloride - 780 µg/L
(Soil) PCE - 564,000 µg/kg; TCE - 5,007 µg/kg
Waste and wastewater from dry cleaning operations
Type/Quantity of Media Treated:
Soil, groundwater, DNAPL
- Blacks: Groundwater, soil, DNAPL; depth to groundwater: varies seasonally from 6 to 12 feet
- Boone: Groundwater, soil; depth to groundwater: 10.11 ft (shallow); 45.87 (intermediate); 65.85 (deep)
- Carousel: Groundwater, soil; depth to groundwater: seasonally varies from 10 to 20 ft bgs
- Former 60: Groundwater, soil; depth to groundwater: 4 ft bgs
- Village Green: Groundwater, soil, DNAPL; depth to groundwater: 4 ft bgs
Purpose/Significance of Application:
Use of in situ bioremediation using various additives to treat soil and groundwater contaminated with chlorinated solvents at dry cleaner facilities.
Regulatory Requirements/Cleanup Goals:
Blacks: Cleanup goals primarily based on vapor intrusion into buildings; preliminary remediation goals (PRGs) for groundwater: 1 µg/L PCE; 100 µg/L TCE; and 20 µg/L vinyl chloride.
Boone: Soil - EPA Region 9 PRGs; Groundwater MCLs
Carousel: Final cleanup goals yet to be established. Likely cleanup goals for groundwater and soil will be based on vapor intrusion modeling, and protection of deep aquifer at the MCL of 5 µg/L for PCE.
Former 60: Groundwater - PCE - 3 µg/L, TCE - 3 µg/L, cis-1,2-DCE - 70 µg/L, trans-1,2-DCE - 100 µg/L; 1,1-DCE - 7 µg/L; vinyl chloride - 1.0 µg/L. Soil: PCE - 30 µg/kg; TCE - 30 µg/kg
Village Green: Groundwater - PCE - 3 µg/L, TCE - 3 µg/L, cis-1,2-DCE - 70 µg/L. Soil (leachability): PCE - 30 µg/kg; TCE - 30 µg/kg
Blacks - Not available
- Wells with greatest PCE impact indicated an 85-95% decrease by August 2002.
- BioRem H-10 was able to degrade PCE without generation and accumulation of more toxic daughter products, namely TCE and vinyl chloride.
- There was a rapid decrease in PCE concentrations in system influent in the first quarter of system operation, coupled with an increase in cis-1,2-DCE in groundwater influent concentrations.
- The site is currently in natural attenuation monitoring with semi-annual dilute ethyl lactate dosing.
- Confirmatory soil sampling revealed that maximum PCE contaminant concentrations in soil decreased from 564,000 µg/kg to 2,300 µg/kg.
- Blacks: Cost for design and implementation was approximately $30,000; costs for operation and maintenance are estimated to be $35,000 per year for the periodic injection of electron donor and bacterial treatment, and $20,000 per year for on-going groundwater, soil gas, and indoor air monitoring.
- Boone and Village Green: Cost data unavailable
- Carousel: 2-year pilot demonstrations costs were $75,000 for the injection system and monitoring. BioRem contributed the H-10 bacteria product for the study
- Former 60: Design costs were $32,300, and construction costs were $107,500; operation and maintenance costs for the first year (includes ethyl lactate, injection, monitoring, and reporting) was $140,2000.
In situ bioremediation was conducted at five drycleaner sites contaminated primarily with chlorinated solvents from drycleaning operations. PCE, TCE, DCE, and vinyl chloride were the main contaminants of concern in soil and groundwater. At two sites (Blacks and Village Green), DNAPLs were present. The remediations, including full-scale and pilot-scale bioremediation, involved the subsurface injection of various additives such as sodium lactate, soybean oil, corn syrup, Simple Green®, vegetable oil, BioRem H-10, and ethyl lactate.
Results of the bioremediation were available for four of the five sites. Reductions in PCE and TCE concentrations and increases in PCE and TCE biodegradation products were reported for all four sites. At Boone, the remedy of corn syrup, Simple Green, and vegetable oil caused the vegetable oil to float on top of water. A lesson learned from this application was that remedial designs that call for injections of oil containing nutrient-enriched emulsions should consider the separation of oil from the emulsion.