MTBE Contamination

Methyl tert-butyl ether (MTBE) is a chemical compound that was widely used as a gasoline additive from the late 1970s through the early 2000s to reduce air pollution from vehicle emissions. While effective at improving air quality, MTBE proved to be a persistent groundwater contaminant due to its high water solubility and resistance to biodegradation, making it one of the most problematic contaminants at LUST sites.

MTBE dissolves readily in water and can travel long distances in groundwater plumes, often extending far beyond the reach of other petroleum contaminants like benzene. Even at very low concentrations, MTBE imparts an unpleasant taste and odor to drinking water. The EPA has issued a drinking water advisory of 20-40 ppb for taste and odor, though many states have set lower standards.

Although MTBE has been largely phased out of gasoline in favor of ethanol, historical contamination from LUST releases continues to affect groundwater supplies across the country. Remediation of MTBE contamination is particularly challenging due to its mobility and resistance to natural attenuation. Advanced treatment technologies such as advanced oxidation, granular activated carbon, and air stripping are commonly employed at MTBE-impacted sites.