FULL-SCALE DEMONSTRATION OF NATURAL ATTENUATION OF MTBE

摘要

A microcosm study performed to assess the potential for natural attenuation or enhanced bioremediation of methyl tertiary-butyl ether (MTBE) in an unconfined groundwater system at the JFK International Airport in Jamaica, New York indicated a significant reduction in MTBE concentrations after 84 days of incubation under anaerobic reducing conditions. Based upon these data, a full-scale study was performed to demonstrate the feasibility of implementing natural attenuation to mitigate MTBE impacts to site groundwater. Multiple lines of evidence identified during the study demonstrated the effectiveness of biologically-mediated natural attenuation of MTBE. These lines of evidence include anaerobic reduced conditions in site groundwater shown to be conducive to biodegradation of MTBE, decreased concentrations of electron acceptors within the plume core, elevated concentrations of tertiary butyl ether (TBA), an MTBE daughter product, detected within and outside the footprint of the MTBE plume, and a significant reduction in MTBE concentrations at wells located within and downgradient of the plume. The half-life for MTBE calculated from field data (120 to 312 days) is within reasonable agreement with the 99-day half-life calculated using data generated from the anaerobic microcosm study. The results of this study demonstrate that natural attenuation can be a viable alternative for remediation of MTBE in groundwater.