The director of the Iowa Department of Natural Resources backs a move to banthe use of an oil-based fuel additive known as “M-T-B-E.” In the 1970s whenlead was removed from gasoline, “M-T-B-E” was used as a substitute. D-N-Rdirector Paul Johnson says 29-percent of underground gas tank sites recentlychecked showed levels of M-T-B-E contamination above acceptable limits.Last year, the legislature restricted M-T-B-E to just two-percent ofa gallon of gasoline. Representative Mark Kuhn, a democrat from CharlesCity, is sponsoring a bill which would completely ban M-T-B-E from Iowa.Dave Smitherman of the Petroleum Marketers of Iowa says there is no M-T-B-Ein Iowa gasoline, and the bill is not needed. He says the state is pre-empted by federal law from doing anything.