The oxygenate tert-butyl alcohol occurred at 61 percent of the sites, and the other three oxygenates–all ethers similar in structure to MTBE–turned up 9 percent to 24 percent of the time.

Chevron Corp. and other big oil companies have agreed to pay $422 million to settle a major lawsuit over the gasoline additive MTBE, and much of the money will go to plaintiffs in California.

New research released Wednesday finds drinking water contamination from the gasoline additive MTBE may be far more widespread than previously thought–perhaps polluting one-third of the nation's ...

Federal regulators have said that MTBE is a possible carcinogen at high doses, and California law limits exposure to 13 parts per billion in water. It can render water undrinkable because of its ...

BP said it would phase out cleaner-burning fuel additive MTBE, or methyl tertiary butyl ether, in California gasoline by Dec. 31, and has begun to sign contracts with several suppliers of the ...