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Clean Air Interstate Rule, Acid Rain Program and Former NOx Budget Trading Program 2012 Progress Report

2012 Progress Reports

Each year EPA releases reports summarizing and evaluating progress under both the Clean Air Interstate Rule (CAIR) and the Acid Rain Program (ARP). These reports show the combined effect of the programs on power sector emissions of SO2 and NOx and the resulting benefits through 2012.

2012 ARP and CAIR at a Glance

CAIR and ARP Annual SO2 Emissions: 3.3 million tons (68 percent below 2005)

CAIR Ozone Season NOx Emissions: 514,000 tons (37 percent below 2005)

CAIR and ARP Annual NOx Emissions: 1.7 million tons (53 percent below 2005)

Compliance: Perfect compliance for all facilities reporting to the CAIR and ARP programs

Health Benefits: By reducing SO2 and NOx emissions (precursors to PM2.5 and ozone formation) the ARP, NPB, and CAIR significantly benefit human health and welfare.

Air Quality: Between 1989 to 1991 and 2010 to 2012, average ambient particulate sulfate concentrations have decreased by 59 percent in the Mid-Atlantic, 57 percent in the Midwest, 63 percent in the Northeast, and 56 percent in the Southeast.

In CAIR states, 99th percentile average 1-hour ozone concentrations decreased by 18 percent between 2000 to 2002 and 2010 to 2012.

Acid Deposition: Between 1989 to 1991 and 2010 to 2012, wet deposition of sulfate decreased by 59 percent across the Eastern United States.

Surface Water Chemistry: Levels of Acid Neutralizing Capacity (ANC) have increased significantly from 1990 in lake and stream long-term monitoring sites in the Adirondack Mountains and the Northern Appalachian Plateau. These increasing ANC levels indicate trends toward recovery from acidification.

Emissions, Compliance, and Market Analyses

Coal train

Published December 2013

Read the full report. | Download as pdf (1.6 MB).

Environmental and Health Results

Lakeside photograph

Published May 2014

Read the full report. | Download as pdf (8.5 MB).

The first report presents 2012 data on combined emission reductions and compliance results for CAIR and the ARP as well as some historic emissions data from the NOx Budget Trading Program (NBP). It includes state-level emission reductions and trends, emission monitoring information, compliance details and analysis of market activity.

The second report evaluates the effects of these emissions reductions programs through improvements in air quality. It summarizes significant benefits to human health, reductions in acid deposition, and trends in recovery from acidification in fresh water lakes and streams.

CAIR, ARP, and NBP States

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CAIR, ARP, and NBP States

Source: EPA, 2013

Photo credit: S.J. Nelson


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