EPA signed the final Cross-State Air Pollution Rule on July 6, 2011. The final rule replaces the 2005 Clean Air Interstate Rule (CAIR). 70 Fed. Reg. 25,162. In 2008, the D.C. Circuit Court of Appeals remanded the CAIR to EPA over the agency’s failure to adequately ensure that upwind emissions reductions would be sufficient to help downwind states meet air quality standards. North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008). The new rule requires power plants in 27 Eastern, Midwestern and Southern states to reduce the interstate transport of sulfur dioxides and nitrogen oxides and is intended to help states downwind of power-plant emissions conform to national ambient air quality standards (NAAQS) for ozone and fine particulate matter. The rule will impose emissions reductions beginning January 1, 2012, with additional requirements due to take effect January 1, 2014.

According to EPA, the final rule’s estimated annual cost of $800 million in 2014 will increase average monthly electricity bills for households by 1 percent. The agency claims the rule would reduce sulfur dioxide emissions from power plants by 73 percent by 2014 and reduce nitrogen oxides emissions by 54 percent, compared with 2005 levels. EPA will accept comments on the 1323-page final rule for 45 days after it is published in the Federal Register.