Because MTBE is water-soluble and neither attaches to soil particles nor biodegrades, it finds its way into water supplies, where a very small amount causes water to be virtually undrinkable and dangerous. So far, no economically viable method of removing MTBE from water supplies has been devised. If MTBE use continues, the national cost of remediating MTBE contamination of water is likely to run into the billions of dollars. In addition, MTBE reduces the efficiency of efforts to remediate water contaminated by other petroleum hydrocarbons. The logical substitute for MTBE in gasoline is ethanol.
Ethanol is the nation's head start into the bio-based economy of the future.
Ethanol provides oxygen to ensure complete oxidation of gasoline components in internal combustion engines, thus reducing emissions of toxic pollutants, including carbon monoxide. By reducing carbon monoxide, ethanol also reduces ozone pollution. Further, ethanol enhances octane levels, thus improving engine performance and fuel efficiency. We do not see a benefit to eliminating the oxygenate requirement, as some propose. According to USDA, by 2004 ethanol could successfully replace MTBE in meeting oxygenate demands with negligible effects on gasoline prices or supplies.