In Situ Bioremediation Using Hydrogen Release Compound® or Molasses at Six Drycleaner Sites, Various Locations

Site Name:

Multiple (6) Dry Cleaner Sites


- Contemporary Cleaners, FL
- Decorah Shopping Center Drycleaners, WI
- Dixie Cleaners, FL
- Hayden Island Cleaners, OR
- Springdale Cleaners, OR
- Washington Square Mall Dry Cleaners, WI

Period of

- Contemporary Cleaners - 154 days, dates not specified
- Decorah Shopping Center Drycleaners - not specified
- Dixie Cleaners - June, 2000 to June, 2001
- Hayden Island Cleaners - 15 months, dates not specified
- Springdale Cleaners - not specified
- Washington Square Mall Dry Cleaners - 20 months, dates not specified


Full-scale remediations and field demonstrations

In Situ Bioremediation
- Injection of hydrogen release compound was performed at 4 sites at depths from 12 to 40 feet. Treatment areas ranged from 200 to 14,600 square feet and total HRC® injected ranged from 2,300 to 22,000 pounds of HRC®. Injection wells were installed using direct push techniques, usually in a grid based on 10-foot centers. HRC® was applied in a single injection.
- Injection of molasses was performed at one site at depths from 12 to 17 feet. The treatment area was not specified. Injection wells were installed using direct push techniques. Six injections were performed over a period of 6 months, with 15-25 gallons of molasses and 25 gallons of water injected during each injection.

Cleanup Authority:

Varied by site

Chlorinated Solvents
- All of the sites were contaminated with PCE or TCE
- Concentrations varied by site ranging from 0.025 to 1,230 mg/L for PCE and 0.00039 to 8.3 mg/L for TCE
- Two sites reported that DNAPLs were present

Waste Source:
Waste and wastewater from drycleaning operations

Type/Quantity of Media Treated:
- Groundwater conditions varied by site
- Plume sizes ranged from 15,000 to 140,000 square feet; treatment areas ranged from 200 to 18,000 square feet.

Purpose/Significance of Application:
Use of in situ bioremediation to treat chlorinated solvents in groundwater at drycleaner facilities

Regulatory Requirements/Cleanup Goals:
- Cleanup goals were based on state regulatory goals or EPA MCLs.
- Specified cleanup goals included 0.003 mg/L for PCE and 0.003 to 0.005 mg/L for TCE

In situ bioremediation with HRC® (5 sites):
- All of the sites reported reductions in PCE and TCE, and evidence of biodegradation, including increases in the concentrations of PCE and TCE degradation products
- Information about progress towards specific cleanup goals was not provided

In situ bioremediation with molasses (1 site):
- Sampling results from a 20-month period following bioremediation indicated that PCE was reduced from 2 mg/L to below analytical detection limits (detection limits were not specified). TCE concentrations were reduced from 0.9 to 0.015 mg/L

Cost Factors:
- Total project costs ranged from $79,000 to treat a 200 square foot area to depths from 25 to 40 feet; to $300,000 to treat an 18,400 square foot area to from 25 to 30 feet
- Costs included well installation, application of the technology, and post-treatment monitoring but do not include site assessment

In situ bioremediation was conducted at six drycleaner sites contaminated with chlorinated solvents from drycleaning operations with TCE and PCE as the primary contaminants in groundwater. The concentrations of TCE and PCE contamination varied by site with levels of PCE in groundwater as high as 1,230 mg/L and TCE in groundwater as high as 8.3 mg/L. The remediations, including full-scale and demonstration-scale projects, involved the subsurface injection of substances to promote bioremediation.

In situ bioremediation was performed using HRC® at five sites and molasses at one site. The injection wells were installed using direct push techniques, and the concentrations of TCE and PCE were monitored after the application of the technology. A single injection of HRC® was performed at the five sites. Reductions in PCE and TCE concentrations and increases in PCE and TCE biodegradation products were reported for all five sites. At one site, molasses was injected 6 times over a period of 20 months. PCE concentrations in groundwater decreased to below analytical detection limits and the site was closed.