PORTLAND – A multimillion-dollar lawsuit against companies responsible for the use of MTBE in gasoline has been settled for $35,000, most of it coming from a motorist’s car insurance.

The suit was filed in Cumberland County Superior Court in 1998 by five homeowners from Standish, Litchfield, Casco, and Cumberland.

It grew out of the sale of gasoline containing methyl tertiary butyl ether, a chemical additive designed to reduce smog.

Maine began requiring the sale of the reformulated fuel to meet federal clean-air mandates in southern Maine in 1995.

The state discontinued the sale of the gas three years later after MTBE began turning up in groundwater.

Plaintiffs in the lawsuit included several people whose wells were contaminated with the chemical.

Others were concerned about the threat of contamination and wanted chemical companies to foot the bill for testing.

The defendants, including Arco Chemical Co., Atlantic Richfield Co., Lyondell Chemical Co., the American Petroleum Institute and the Oxygenated Fuels Association, were accused of negligent misrepresentation, civil conspiracy and fraud for failing to warn of the potential for water contamination.

But the plaintiffs failed to win certification as a class, meaning they could not sue on behalf of other people affected.

William Kayatta, a lawyer who represented Arco Chemical Co. and Lyondell Chemical Co., said the defense was able to show that state and federal environmental regulators were aware that MTBE mixed easily with water and could spread in groundwater.

But regulators determined that the benefits to air quality were worth the potential harm to groundwater, he said.

Plaintiff Michael Millett of Standish was one of the first in Maine whose well was found to contain high levels of MTBE contamination.

The source of the chemical was traced to gasoline that spilled from a car involved in a rollover accident.

That led to Commercial Union, which insured the car, to pay $25,000 toward the settlement.

The remaining $10,000 came from Atlantic Richfield Co., an oil company that once manufactured the chemical.

Kayatta said the defense insisted the settlement be open to public inspection to demonstrate that his clients, the current manufacturers of the chemical, did nothing wrong.

“Their position nationwide has been ‘we did absolutely nothing wrong,'” Kayatta said.

“The government and the refiners asked us to make this ingredient for gasoline that would clean up the air and it behaved exactly as we said.”