Air Quality

On December 17, 2003, the Environmental Protection Agency (EPA) issued a proposed rule to address the effect of interstate transport of air pollutants on nonattainment of the National Ambient Air Quality Standards (NAAQS) for fine particulates (PM2.5) and ozone (specifically, the 8-hour standard). The proposed Interstate Air Quality (IAQ) rule appeared in the Federal Register January 30, 2004. For PM2.5, the proposed rule finds that the interstate transport of sulfur dioxide (SO2) and nitrogen oxides (NOx) from 28 states and the District of Columbia contributes significantly to downwind non-attainment; for ozone, the proposed rule finds that interstate transport of NOx from 25 states and D.C. contributes significantly to downwind non-attainment of the 8-hour standard.