The Environmental Protection Agency is looking to simplify one of its most confusing regulations by proposing changes to the Waters of the United States rule. The proposal would shift more water quality enforcement to the states and narrow the types of waterways protected at the federal level. The new definition would remove ditches, converted cropland, groundwater and some waste systems from federal oversight. Supporters say the change cuts red tape and lowers costs for farmers and developers, while environmental groups worry it could weaken protection for wetlands that help prevent pollution and flooding. A forty-five-day public comment period is now underway.