Clean Air Interstate Rule (CAIR)
Like the NOx SIP Call and SO2 Acid Rain programs, CAIR provides a federal framework that requires state-wide reductions of NOx and SO2 emissions.
The EPA issued the Clean Air Interstate Rule on March 10, 2005, mandating the largest reduction in air pollution in more than a decade. This program will cover the entire eastern portion of the United States, and is intended to achieve an overall reduction of millions of tons in emissions. CAIR will permanently cap emissions of sulfur dioxide (SO2 ) and nitrogen oxides (NOx) in the affected region, and will supersede the NOx SIP Call and SO2 Acid Rain Credits program (see below).
States may opt to achieve the required reductions by allowing their power plants to participate in an EPA-administered interstate cap-and-trade system. Any state not wishing to participate in the interstate cap-and-trade program must meet the emissions budget set for it by the EPA through conservation, technology or an intrastate cap-and-trade program.
CAIR expands the ozone-season NOx program from 19 to 25 States. It will replace the NOx SIP Call starting in 2009. CAIR introduces a new and separate annual NOx program for at least 23 states starting in 2009, which will proceed to a second and more restrictive stage in 2015.
CAIR regulates all fossil fuel-fired electricity generating boilers, turbines, and integrated gasification combined cycle plants with generators whose capacity exceeds 25 megawatt. New coal-fired power units constructed after January 30, 2004 will have to satisfy new source performance standards in addition to being subject to cap restrictions.
Because the Clean Air Act requires states to meet the new national air quality standards by requiring reductions from many types of sources, some areas may need to take additional local measures for compliance. Sources outside of the CAIR cap-and-trade program may be required to implement Best Available Retrofit Technology (BART) to satisfy visibility requirements.