Affected Units Figures
Source: EPA, 2018
Last updated: 05/2018
Acid Rain Program (ARP)
- In 2016, the ARP SO₂ requirements applied to 3,446 fossil fuel-fired combustion units at 1,216 facilities across the country; 710 units at 314 facilities were subject to the ARP NOₓ program.
Cross-State Air Pollution Rule (CSAPR)
- In 2016, there were 2,708 affected EGUs at 846 facilities in the CSAPR SO₂ program. Of those, 2,160 (80 percent) were also covered by the ARP.
- In 2016, there were 2,708 affected EGUs at 846 facilities in the CSAPR NOₓ annual program and 3,106 affected EGUs at 929 facilities in the CSAPR NOₓ ozone season program. Of those, 2,160 (80 percent) and 2,474 (80 percent), respectively, were also covered by the ARP.
Analysis and Background Information
In general, the ARP and the CSAPR SO₂, NOₓ annual, and NOₓ ozone season trading programs apply to large EGUs—boilers, turbines, and combined cycle units– that burn fossil fuel, serve generators with nameplate capacity greater than 25 megawatts, and that produce electricity for sale. These EGUs include a range of unit types, including units that operated year-round to provide baseload power to the electric grid, as well as units that provided power only on peak demand days. The ARP NOₓ program applies to ARP-affected units that are older, historically coal-fired boilers.