The Acid Rain Program, established under Title IV of the 1990 Clean Air Act Amendments (CAAA), requires major reductions of sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions from the electric power industry. Similarly, other programs such as the Ozone Transport Commission (OTC), NOx Budget Trading Program and the EPA's NOx State Implementation Plan (SIP), both of which are seasonal and regional NOx reduction programs also require emissions reductions from the power sector. In the spring of 2005, EPA promulgated a suite of air quality rules designed to further the reductions of SO2 and NOx, as well as mercury (Hg) emissions from power plants. These new rules include the Clean Air Interstate Rule (CAIR), the Clean Air Mercury Rule (CAMR), and the Clean Air Visibility Rule (CAVR). Assessing the environmental impacts of power generation such as regional air quality and atmospheric deposition of sulfur, nitrogen, and mercury is important to understanding and evaluating the progress of these emission reduction programs. EPA adheres to several mandates such as Title IX of the Clean Air Act, the Government Performance and Results Act (GPRA), and the Program Assessment Rating Tool (PART) to report on the performance and overall progress of these programs.