EPA Report Says Air Quality in Eastern U.S. Improved by CAIR, Other Regulatory Efforts

By Jessica Coomes  

The Environmental Protection Agency is crediting the Clean Air Interstate Rule and other emissions reduction programs with cutting emissions of nitrogen oxides and sulfur dioxide, helping to improve air quality in Eastern states.

The average eight-hour ozone concentrations from 2008 to 2010 in states in the Eastern half of the country that are subject to CAIR were 16 percent lower than average from 2001 to 2003, after accounting for weather variations, according to an EPA progress report on CAIR, the former nitrogen oxides budget trading program, and the acid rain program.

Fine particulate matter concentrations have dropped 22 percent in the warm season and 13 percent in the cool season during the same period, after accounting for the weather, according to the report.

Three Programs.

EPA continues to administer the CAIR program to reduce emissions of nitrogen oxides and sulfur dioxide from power plants in the East. The agency promulgated a replacement program, the Cross-State Air Pollution Rule, but the U.S. Court of Appeals for the District of Columbia Circuit has stayed it while legal challenges play out (EME Homer City Generation L.P. v. EPA, D.C. Cir., No. 11-1302, oral arguments 4/13/12).

EPA administered the nitrogen oxides budget trading program from 2003 to 2008 under a cap-and-trade program to address interstate transport of nitrogen oxides, which was called the “NOx SIP Call.”

Congress established the acid rain program under Title IV of the Clean Air Act Amendments of 1990. Sulfur dioxide and nitrogen oxides are the primary precursors to acid rain.

NAAQS Progress.

The May progress report credited the three emissions reductions programs for helping to reduce pollution in areas of Eastern states found to be in nonattainment of the 1997 ozone and fine particulate matter national ambient air quality standards.

The ozone attainment designations were based on air quality data from 2001 to 2003, and 91 areas in the East were in nonattainment. Air quality data from 2008 to 2010 shows 90 of those areas report ozone concentrations that are below the 1997 standard of 0.08 part per million.

For fine particulate matter, 36 Eastern areas were in nonattainment of the 1997 standard, based on 2001 to 2003 data. Today, 2008 to 2010 data show 34 areas with concentrations below the standard of 15 micrograms per cubic meter.

EPA said the three programs have been “a significant contributor” in the air quality improvements.

By Jessica Coomes  

The progress report is available at http://www.epa.gov/airmarkets/progress/ARPCAIR_downloads/ARPCAIR10_environmental_health.pdf.