Smog threatens the human respiratory system, and can aggravate asthma, particularly in children, and reduces lung capacity. Smog also makes crops more susceptible to disease and pests. Reducing these emissions also helps prevent acid rain, contaminated water bodies and regional haze. In May 1999, as an interim measure, the U.S. Court of Appeals issued a temporary stay of the deadline for submittal of state plans to implement the rule. Facilities in those states then will have to install air pollution controls by May 1, 2003.
States have maximum flexibility to decide how to achieve the required reductions.
However, EPA anticipates that many states will target large coal-fired power plants that have largely been unregulated and provide the opportunity for highly cost effective pollution reduction to meet these goals. Additionally, EPA will propose a rule this spring to target downwind smog problems caused by areas of Georgia and Missouri, an issue which the court remanded in its decision. Those states will not need to submit plans until that rule is final. Consistent with the court's decision, EPA also plans to adjust emission reduction targets for Alabama and Michigan.