Associated Press 08-08-07 Expert warns state about ethanol pollution Associated Press DES MOINES, Iowa (AP) - An environmental expert is warning the state that the ethanol boom may pollute streams in the coming years and contribute to global warming. Rick Cruse is director of Iowa State University's Iowa Water Center. He says decisions on how to grow corn to make ethanol will dictate whether the biofuels industry becomes an ecological disaster. Cruse made the comments this week to the Iowa Environmental Protection Commission, which helps writes state environmental rules. He says there could be conflicts if the nation moves to convert corn stubble into ethanol. Since corn stubble is needed to replenish the soil, that could mean less fertile soil and higher soil erosion. He says climatic trends pointing to heavier rainfall in the Midwest would only make the erosion problem worse. Cruse advocates using multiple crops to lessen the erosion threat. Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.