Minnesota has dodged drinking water problems that plague other areas of the nation thanks to use of ethanol in fuel, rather than another fuel additive, MTBE, experts say.

Monday, February 07, 2000

Minnesota has dodged drinking water problems that plague other areas of the nation thanks to use of ethanol in fuel, rather than another fuel additive, MTBE, experts say.

MTBE was designed to make fuel burn cleaner in vehicles, protecting the air.

But while the air is cleaner, the fuel additive MTBE is now being blamed for contaminated drinking water in some cities.

The problem is especially bad in places like California and New England, where MTBE is used most. Leaks from underground storage tanks at service stations and refineries, and spills from fuel trucks have caused wells to be closed. Lawsuits have cropped up in many states and millions are being spent in cleanup costs.

In Minnesota, however, MTBE reportedly is not as great a threat because of widespread use of ethanol, an alcohol-based fuel additive that serves the same purpose.

Ethanol, unlike MTBE, is not linked to drinking water contamination because it breaks down in the environment far better, experts say.

Ethanol vs. MTBE

MTBE, or methyl tertiary butyl ether, is now found in the fuel consumed by 70 percent of the nation’s cars.

A product of the federal Clean Air Act of 1990, the petroleum-based MTBE is produced by oil companies and also often is used to increase engine performance. As a result of federal legislation, states were mandated to use a fuel additive, either MTBE or ethanol, to reduce toxic fumes in the air that produce smog.

In Minnesota and other Midwestern states, ethanol was the fuel additive of choice. Minnesota uses ethanol – a type of alcohol made from corn in plants like EXOL, outside Glenville – almost exclusively.

While the effects of MTBE on humans is not known, it has been shown to cause liver and kidney cancer in lab mice.

"MTBE can be found everywhere in this country today," said Cathy Carlson of the Minnesota Pollution Control Agency. "It was used here in the state of Minnesota in the mid-1980s as an octane booster. We can still find traces of it here, in pipelines and at the pump.

"It’s not as serious a problem here," she said. Carlson notes a 2 percent blend of MTBE could be used to increase engine performance. A higher ratio blend, up to 15 percent or more, was used in many states to get the desired effect of cleaner air, she said.

"Minnesota banned the sale of MTBE here after the Clean Air Act and adopted ethanol as the gas additive we would use in order to be in compliance with federal clean air requirements," Carlson said. "Virtually every car and every gas station in the state uses ethanol."

Carlson cautioned that while the state has dodged a bullet as far as major problems with MTBE ground water contamination, that doesn’t mean it can’t be found here.

"There are plants that manufacture MTBE here in the state, though they are banned from selling it here," Carlson said. "There are also reported spills where the presence of MTBE has been detected."

One of every five spill sites in Minnesota contains trace amounts of MTBE, Carlson said.

A ratio of 20 to 40 parts per billion generally is considered a safe amount of MTBE when detected. At oil refineries, there can be as much as 13,000 ppb in the environment, Carlson said.

MTBE has a strong smell of kerosene even in small amounts. It dissolves in water, allowing it to move more quickly than other contaminants. The EPA has recommended that drinking water with a MTBE ratio higher than 40 ppb may not be safe for drinking or cooking.

California – with about 11 percent of all fuel containing MTBE – has banned it by the end of 2002, and other states are expected to follow suit.

In Santa Monica, hit first and hardest by major MTBE contamination in 1995, the substance leaked into the water supply from the underground tanks of at least a dozen service stations.