On the eve of Earth Day, a democrat lawmaker is accusing republicans of failing Iowa’s environment.Representative Bill Witt, a democrat from Waterloo, was at one time president of the Iowa Sierra Club. Witt says throughout the 1990s, republican legislators cobbled the ability of regulators to crack down on polluters.But Republican Senator Merlin Bartz of Grafton says the republican-led legislature has made major progress on environmental issues in the past few years. He says he’s proud of the bill passed to clean up the state’s waterways, which passed with support from both parties.Bartz and Witt made their comments during taping of an Iowa Public Television program.