Number: RL32755
Title: Air Quality: Multi-Pollutant Legislation in the 109th Congress
Authors: Larry Parker and John Blodgett, Resources, Science, and Industry Division 
Abstract: Electric utility generating facilities are a major source of air pollution. The combustion of fossil fuels (petroleum, natural gas, and coal), which accounts for about two-thirds of U.S. electricity generation, results in the emission of a stream of gases. These gases include several pollutants that directly pose risks to human health and welfare, including particulate matter (PM), sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury (Hg). Particulate matter, SO2, and NOx are currently regulated under the Clean Air Act (CAA), and the Environmental Protection Agency (EPA) has promulgated rules to regulate mercury beginning in 2010. Other gases may pose indirect risks, notably carbon dioxide (CO2), which may contribute to global warming. Table 1 provides estimates of SO2, NOx, and CO2 emissions from electric generating facilities. Annual emissions of Hg from utility facilities are more uncertain; current estimates indicate about 48 tons. Utilities are subject to an array of environmental regulations, which affect in different ways both the cost of operating existing generating facilities and the cost of constructing new ones.
Pages: 10
Date: May 8, 2006