E.I. Du Pont has reached a settlement with the Department of Justice and the EPA to reduce emissions at four sulfuric acid plants in as many states by 13,000 tons. The company expects to spend an estimated $66 million to meet lower emission limits for its Darrow, La., plant, and has the option to close the other three operations or upgrade them to meet the requirements by March 1, 2012. The Darrow plant will be equipped with a state-of-the-art dual absorption process by Sept. 1, 2009.