US EPA has posted The Acid Rain Program 2005 Progress Report. The report states that during its eleven years the Acid Rain Program has:
- Reduced SO2 emissions by over 5.5 million tons from 1990 levels, or about 35 percent of total emissions from the power sector. Compared to 1980 levels, SO2 emissions from power plants have dropped by more than 7 million tons, or about 41 percent;
- Cut NOx emissions by about 3 million tons from 1990 levels, so that emissions in 2005 were less than half the level anticipated without the program. Other efforts, such as the NOx Budget Trading Program in the eastern United States, also contributed significantly to this reduction;
- Led to significant cuts in acid deposition, including reductions in sulfate deposition of about 36 percent in some regions of the United States and improvements in environmental indicators, such as fewer acidic lakes; and
- Provided the most complete and accurate emission data ever developed under a federal air pollution control program and made that data available and accessible by using comprehensive electronic data reporting and Web-based tools for agencies, researchers, affected sources, and the public.