The U.S. Environmental Protection Agency embarked on an ambitious schedule of air pollution rulemaking following the vacatur of several Bush Administration rulemakings. The “transport rule” seeks to cap interstate emissions of sulfur dioxide (SO₂) and nitrogen oxides (NO_x) from power plants to replace the Clean Air Interstate Rule (CAIR). Also scheduled are: a plan to review and update hazardous air pollution rules covering 28 types of industrial facilities; rules limiting mercury and other toxic emissions, including arsenic, dioxins, and hydrochloric acid; national health standards for ozone; and BACT standards that will likely address greenhouse gases. On October 20, 2010, at ELI’s Fall Practice Update, panelists discussed how these various rules interrelate and how they might fit with legislative developments in the next two years.