The Wisconsin State Assembly Agriculture Committee heard testimony at the Capitol Thursday on Assembly Bill 15, which, if passed, would require ethanol levels of 9.2 to 10 percent in all automotive gasoline in Wisconsin.

State Rep. Stephen Freese, R-Dodgeville, and State Sen. Sheila Harsdorf, R-River Falls, co-sponsor the bill, which was referred by the Legislature to the committee.

Freese and Harsdorf said they support the bill because they say a requirement of 10 percent ethanol in gasoline would strengthen Wisconsin’s rural economy, lessen Wisconsin’s dependence on foreign oil and ensure cleaner air.

Ethanol, which is made from biological feedstocks such as corn or sugar cane, would bring $110 million into the local economy, according to Freese. Wisconsin has three ethanol plants, with more on the way.

Freese mentioned Minnesota, which requires 10 percent ethanol in gasoline and is considering raising that level to 20 percent, as a model for the bill.

“E10 has already made a world of difference in the state of Minnesota,” Freese said during the committee hearing.

Freese also mentioned some foreign countries with even higher levels of ethanol in their fuel. In Brazil, some cars run off pure ethanol, further reducing its dependence on foreign oil.

Gasoline retailers opposed the bill, saying it is unnecessary because much of Wisconsin already complies with 10 percent ethanol — particularly the Milwaukee area — and because the environmental benefits remain uncertain. Some environmental groups oppose the bill, including the Sierra Club, because the bill requires only ethanol to be used, rather than other biofuels.

Another point argued during the meeting was ethanol is a net energy loser, requiring more energy to produce than it creates.

Harsdorf responded by noting recent claims doubting the efficiency of ethanol use are based on studies conducted 20 to 30 years ago and today’s plants are producing ethanol more efficiently.

“Ethanol is a better energy source,” Harsdorf said.

But more concerns about E10’s possible negative impact on the environment were voiced by Al Shea of the Wisconsin Department of Natural Resources, saying E10 could have a “marginal negative impact” on ozone formation.

Shea recommended the bill to the committee with reservations, saying the bill will have to be friendlier to both industry and the environment. He advocated E10 should be made to emit the same levels of ozone as conventional gasoline to meet EPA standards, raising the cost of fuel. Shea also recommended all gas cans and gas tanks in the state have special caps to reduce evaporation of the fuel into the air.

Some issues will still have to be considered during the reworking of the bill. Changing the timeline of implementation and instituting a waiver mechanism to the bill in case of ethanol shortages still need to be addressed, said Kurt Simetic, spokesman for Freese.

“Ultimately we think we will bring it to the floor,” he said.

The testimony and the proposed amendments will be taken under consideration when the committee reconvenes in two weeks for a vote on the bill.