AUGUSTA – While legislators debated Tuesday afternoon whether to join much of New England in banning the highly polluting gasoline additive known as MTBE, the petroleum industry argued for more time to make the inevitable shift.

“Everyone can see the MTBE ban on the horizon,” Jim Brooks, director of the Maine Department of Environmental Protection’s Bureau of Air Quality, told legislators as they held a public hearing on a bill seeking to ban the additive in Maine by 2006.

In recent years, methyl tertiary-butyl ether has been used to increase the octane rating of gasoline, which means that motorists get an efficient fuel that burns more of the chemicals that would otherwise become air pollution.

MTBE replaced more toxic lead, improved air quality and was embraced by environmental agencies across the country – until the colorless, tasteless pollutant began appearing in wells. Maine was among national leaders in discovering the carcinogenic chemical’s affinity for water during the 1990s. In fact, a state study found MTBE in 7 percent of public water supplies.

Seventeen states already have banned MTBE, with most located in the Midwest, where ethanol – a plant-based fuel than can be blended with gasoline to achieve the same goals as MTBE – is produced. New York and Massachusetts will both implement their MTBE bans this year, while Maine joins New Hampshire, Connecticut, Rhode Island and New Jersey in considering bans.

Nationwide, about a third of all gasoline sold contains an additive to address air pollution problems. Eighty percent of the time, it’s MTBE. Although Maine in 1999 abandoned reformulated gas, which contained about 15 percent MTBE, our gas still includes between 2 percent and 3 percent MTBE on average, according to DEP data.

The DEP is advocating a switch to ethanol by April 2006. Without a clear deadline, the state might never see results, Brooks said.

Ethanol is believed to produce clean air without risk to water. And the renewable fuel could someday be produced from potato or wood waste, to be mixed with gasoline, Brooks said.

However, ethanol introduces its own environmental problems. When an ethanol-gasoline blend is spilled, soil microbes will go straight for the ethanol, allowing the more hazardous components of gasoline to remain in the environment, he said.

Though he believes a ban could “end the federally mandated poisoning of America,” Julian Holmes of Wayne worried that, like MTBE and lead, ethanol is being embraced before its impact is well understood, he told legislators.

“It’s time to stop this process of replacing one harmful additive with another,” he said.

Industry groups, too, proposed caution Tuesday.

Two years is not long enough to make the transition from MTBE to ethanol or some other type of gasoline, they said.

Transportation and storage of gasoline blended with ethanol also would have to be overhauled. Without further study, it’s impossible to say how long the infrastructure shift would take, said Patricia Aho of the Maine Oil Dealers Association. “Let’s not rush to an unworkable date,” she said.

Stephen Dodge of the New England Petroleum Council asked the state to delay its ban until the nation, or at least all of the Northeast, decides to act in concert. Maine should watch what happens to prices in New York and Massachusetts this summer before requiring a ban, he said.

When states mandate a “patchwork quilt” of different gas formulations, gasoline shortages and subsequent price spikes can occur, Dodge said, citing examples in California and the Midwest. “I don’t think Maine, or any other state, for that matter, should be in the position of being out on a limb by itself,” he said.

The Legislature’s Joint Standing Committee on Natural Resources has scheduled a work session on the bill, LD 1870, for 2 p.m. Thursday, March 11.