EPA is set to issue proposed regulations in the Federal Register that would require Electrical Generating Units (EGUs) above 25 MW in 27 eastern states and Washington, D.C., to reduce emissions of NOx and SO2 and EGUs in an additional four states to limit emissions of only NOx. EPA proposes to allow for interstate trading of emissions allowances under restrictions designed to ensure that each state is able to meet National Ambient Air Quality Standards (NAAQS).