In Situ Bioremediation Using ORC® at an Active Service Station, Lake Geneva, Wisconsin

Site Name:

Service Station, WI


Lake Geneva, Wisconsin

Period of

280 days in duration (specific dates not provided)


Full scale


Steve Koenigsberg
Regenesis, Inc.
1011 Calle Sombra
San Clemente, CA 92672
Telephone: (949) 366-8000
Fax: (949) 366-8090

In Situ Bioremediation using Oxygen Release Compound (ORC®)
- A total of 17,000 pounds of ORC® slurry (magnesium peroxide compound) was injected into the backfill excavation using a Geoprobe® (direct push) and 37 injection points
- Two monitoring wells, located downgradient of the former UST area, were used to monitor levels of MTBE and BTEX in the groundwater

Cleanup Authority:

- MTBE concentrations as high as 800 ug/L
- BTEX concentrations as high as 14,000 ug/L

Waste Source:
Leaks from gasoline storage tanks

Type/Quantity of Media Treated:
-The groundwater flow is generally to the east northeast at a velocity of 0.2 ft/day

Purpose/Significance of Application:
Use of in situ Bioremediation using ORC® to treat MTBE in groundwater

Regulatory Requirements/Cleanup Goals:
No information about specific treatment goals was provided

After nine months of operation, concentrations of MTBE in the two wells had been reduced to levels below 2 ug/L, from initial concentrations of 800 ug/L and 70 ug/L, respectively.
- During the first month of operation, MTBE concentrations in one well increased from about 800 ug/L to 1,800 ug/L, then showed a steady decline over the next eight months. MTBE concentrations in the other well declined rapidly during the first three months of operation and remained at low levels during the next five months of operation.

Cost Factors:
No cost information for this application was provided.

Groundwater at a service station, located in Lake Geneva, Wisconsin, was found to be contaminated with high levels of MTBE and BTEX. Concentrations as high as 800 ug/L for MTBE and 14,000 ug/L for BTEX were detected in the contaminant plume. The source of the contamination was a leaking underground storage tank. Source control activities included removal of the UST and excavation of contaminated soil. Following the removal of the UST and contaminated soil, ORC® was injected into the groundwater to enhance aerobic biodegradation in the saturated zone.

The application of ORC® slurry at the Lake Geneva former UST site reduced MTBE concentrations in groundwater from initial concentrations as high as 800 ug/L to less than 2 ug/L in nine months. MTBE groundwater concentrations dropped significantly within the first three months following injection, and remained at low levels throughout the next six months. According to Regenesis, the site has been submitted to the state for closure.