Title I implementation: Status report on nonattainment areas

Abstract

Key provisions of Title I of the Clean Air Act Amendments of 1990 (CAAA) focus on bringing cities and other areas into attainment of the National Ambient Air Quality Standards for ozone, carbon monoxide (CO), and fine particulates (PM-10). The CAAA's new classification scheme for pollutant nonattainment areas is based on the relative severity of pollution in these areas and determines the stringency of control measures and the dates by which attainment of the standards will be required. The US Environmental Protection Agency's (EPA's) final rule on air quality designations and classifications, published in late 1991, shows that ozone pollution remains a persistent problem; the number of counties that fail to meet the ozone standard has sharply increased since 1987. In contrast, incidence of PM-10 pollution has decreased; many counties have achieved the PM-10 standard since 1987. Nationwide, the number of CO nonattainment areas has increased, though not dramatically. Many of the new Title I requirements focus on the role of nitrogen oxides (NO[sub x]) in the formation of ground-level ozone. In ozone nonattainment areas and ozone transport regions, Title I generally requires major sources of NO[sub x] to have the same control measures as those that apply to major sources of volatile organic compounds (VOCs). This requirement compels state regulators to adopt an integrated VOC/NO[sub x] control strategy. The NO[sub x] emission standards proposed by state regulators are considerably more stringent than those given in federal guidelines. Both the EPA and the states plan to allow the use of multifacility emissions averaging in state NO[sub x] control strategies, thereby providing industry flexibility. Proposed federal Economic Incentive Program (EIP) rules would also allow sources in states with approved EIPs to use mobile source emission reduction credits to meet certain stationary source emission reduction requirements.