ORAN -- Discovery of a contaminant in Oran's well-water supply may mean the community will have to dig new wells, the mayor said.

MTBE, an octane booster for gasoline, has found its way into the water supply, which comes from two deep wells within 100 feet of each other. The wells serve more than 500 homes and businesses in the north Scott County community.

MTBE was first added to gasoline in 1979, said the mayor, Tom Urhahn. In animals, high dosages have been known to cause blood chemistry changes and other chemical abnormalities, but its effects on humans are unknown, he said.

Urhahn said tests showed the level of MTBE in the water to be very low. He said he was told by the Missouri Department of Natural Resources and Department of Health that the water is safe to drink.

But, he said, the chemical can't be neutralized. "Once MTBE enters a water supply it is there to stay," he said. "They tell us that if it gets bad enough it will generate a strong enough odor that people will back off from it."

Urhahn said if that happens the water would be considered unsafe.

Letters are being sent to water customers explaining the situation and informing them the water is safe for consumption, the mayor said.

Meanwhile, the community has hired an engineering firm to study possible sites for one or more new wells. Urhahn said the city has a another well that hasn't been used for many years, and it may be possible to use water from it until a permanent supply is established. Tests of water samples from the old well will be done next week, he said.

The mayor said no one had complained about the water. The contaminant was discovered when an annual test was done on water samples March 24, he said. When that type of test was last done in September 1997, there was no trace of MTBE in the water, he said.

Urhahn said it is unknown how the contaminant entered the well.

Weekly testing of the water will be done by the state, said the mayor.