Downwind Ozone: Clearing the Air

increasingly concerned that the transport of ozone contributes to air quality problems in those states. At the same time, northeast states also faced more stringent requirements under the Clean Air Act to improve unhealthy air quality. These pressures led to a series of rulemakings and lawsuits that have created a stormy and cloudy future for ozone control. The Clean Air Act establishes a federal-state partnership to address air pollution. EPA is authorized to establish national ambient air quality standards (NAAQS) for air pollutants to protect human health and welfare. 42 U.S.C. § 7409. EPA has established NAAQS for several pollutants, including a one-hour and an eight-hour standard for ozone. 40 C.F.R. §§ 50.9, 50.10. States implement the NAAQS by developing implementation plans (SIPs), subject to EPA approval, consisting of regulations for implementation and enforcement of the NAAQS. 42 U.S.C. § 741 0(a). Areas designated by EPA as must meet specific requirements to achieve compliance by prescribed deadlines, depending on the severity of the problem. 42 U.S.C. §§ 7502, 7511. By November 1994, states in nonattainment areas were to submit demonstrations showing that their SIPs would result in attainment by the prescribed dates. November 2007 was the deadline for the one-