MTBE BIOREMEDIATION: RONAN, MT

System Type:

Biological Reactive System, as a demonstration project with EPA, et. al Installed with research partner, EPA , using BioNets™ and a BioWall™
Location:

MTBE Bioremediation, Ronan, Montana, November, 2000
Client:

Environmental Protection Agency, Denver, Colorado

Project Description:

MTBE, a gasoline additive, is a persistent and foul tasting contaminant that is more mobile in groundwater than BTEX (benzene, toluene, ethylbenzene, xylenes). It is turning up at many American crossroads. The objective of this well-controlled study was to determine if biologically active in situ BioNets could bioremediate MTBE contaminated groundwater.

This Foremost X-PeRT™ System included seven BioNets, most containing 3 fractures each, and a BioWall placed into a site on the Flathead Indian Reservation in Montana. The MTBE and BTEX plume from a retail gasoline station was contaminating farmland and threatening Native American owned surface waters. (The shallow protective BioWall trench was installed by Foremost Solutions as a complimentary supplement to the demonstration 100 yards west of the BioNets and just up-gradient of the Indian owned creek adjacent to the treated site.) The BioNets contained: 1) sand or Isolite as a fracture material, which created bioremediation zones by facilitating inoculation, allowing attachment of the bacteria, presenting a zone for addition of oxygen by way of aeration or addition of Solid Oxygen Source (SOS) and enhancing the porosity/permeability of the subsurface; 2) PM1, an aerobic bacteria known to degrade MTBE, which can be monitored with a genetic probe; 3) nutrients; and 4) oxygen as air or SOS.
Results indicate that 12 months after inoculation the reductions of MTBE in the groundwater samples were as high as 85 percent where optimum conditions existed for biodegradation, which included PM1 inoculated Isolite with SOS or air. The use of SOS stimulates more or as much reduction as the use of oxygen as supplied air at various flow rates. After 12 months, DNA of PM1 was isolated from soils from the inoculated BioNets, but not the uninoculated BioNet. PM1 and naturally occurring MTBE degraders were consistently identified on subsurface soil samples using Taqman geneprobe and standard microbial techniques.
A paper entitled "MTBE Bioremediation With BioNets Containing Isolite, PM1, Solid Oxygen Source (SOS) or Air," which was published in the proceedings of The Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds (May 20-23, 2002; Monterey, CA).