2016 Program Progress – Cross-State Air Pollution Rule and Acid Rain Program
This report summarizes annual progress through 2016 under the Acid Rain Program (ARP) and the Cross-State Air Pollution Rule (CSAPR). This reporting year marks the second year of the CSAPR implementation and twenty-first year of the ARP.
Substantial reductions in power sector emissions of sulfur dioxide (SO₂) and nitrogen oxides (NOₓ), along with improvements in air quality and the environment, demonstrate the success of these programs. Transparency and data availability are a cornerstone of this success. This report highlights data that EPA systematically collects on emissions, compliance, and environmental effects.Read historical reports of EPA's Clean Air Markets Programs
2016 ARP and CSAPR at a Glance
- Annual SO₂ emissions:
CSAPR - 1.2 million tons (87 percent below 2005)
ARP - 1.5 million tons (91 percent below 1990)
- Annual NOₓ emissions
CSAPR - 0.8 million tons (69 percent below 2005)
ARP - 1.2 million tons (81 percent below 1990)
- CSAPR ozone season NOₓ emissions: 420,000 tons (53 percent below 2005)
- Compliance: 100 percent compliance for power plants in the ARP and CSAPR programs.
- Ambient particulate sulfate concentrations: The eastern United States has shown substantial improvement, decreasing 71 to 75 percent between 1989–1991 and 2014–2016.
- Ozone NAAQS attainment: Based on 2014-2016 data, all 92 areas in the East originally designated as nonattainment for the 1997 ozone NAAQS are now meeting the standard.
- PM₂.₅ NAAQS attainment: Based on 2014-2016 data, 34 of the 39 areas in the East originally designated as nonattainment for the 1997 PM₂.₅ NAAQS are now meeting the standard (two areas have incomplete data).
- Wet sulfate deposition: All areas of the eastern United States have shown significant improvement with an overall 66 percent reduction in wet sulfate deposition from 1989–1991 to 2014–2016.
- Levels of acid neutralizing capacity (ANC): This indicator of recovery improved (i.e., increased) significantly from 1990 levels at lake and stream monitoring sites in the Adirondack region, New England and the Catskill mountains.