SO2 Emissions from Power Plants Continue to Decrease
Power plants across the country decreased emissions of sulfur dioxide (SO2), a precursor to acid rain, to 7.6 million tons in 2008, according to the U.S. Environmental Protection Agency's Acid Rain Program report.
Emissions from sources in the program fell by 52 percent compared with 1990 levels and are already below the statutory annual emission cap of 8.95 million tons set for compliance in 2010.
Key achievements of the program include:
- All 3,572 electric generating units subject to the program’s SO2 requirements held enough allowances to cover their SO2 emissions, resulting in 100 percent compliance in 2008;
- Emission reductions under the Acid Rain Program have led to improvements in air quality with significant benefits to human health; and
- Sensitive waterbodies in the East are showing signs of recovery from acidification.
The Acid Rain Program was established under the 1990 Clean Air Act Amendments and requires major emission reductions of SO2 and nitrogen oxides (NOx) from the electric power industry. The program sets a permanent cap on the total amount of SO2 that may be emitted by electric generating units in the United States, and includes provisions for trading and banking allowances. The program is phased in, with a final 2010 SO2 cap set at 8.95 million tons, a level of about one-half of the emissions from the power sector in 1980.