Sorption and biodegradation of methyl tert-butyl ether and tert-butyl alcohol in hypoheic zone soils

Gasoline containing MTBE, a fuel oxygenate, was accidentally released from a leaking underground fuel tank (LUFT) and entered an unconfined aquifer in Ronan, Montana. The presence of TBA has also been observed at the site in the MTBE groundwater plume likely resulting from in situ biodegradation of MTBE. Monitored natural attenuation (MNA) has been proposed as a treatment alternative for the MTBE and TBA groundwater plume at the Ronan site. This study was undertaken to measure the biological mineralization of TBA and sorption of MTBE and TBA to Ronan hyporheic zone to determine the feasibility of MNA as a remediation alternative at the site.; The ability of the Ronan hyporheic zone to biodegrade TBA was demonstrated using soil microcosms. Temperature effects on TBA mineralization first order kinetics were also observed. Sorption of MTBE and TBA was observed in seven hyporheic zone soils. MTBE sorption was linear and significantly higher than the literature predicted.