What Does the Clean Air Act Say about Cross-State Air Pollution?
Clean Air Act Section 110
The Clean Air Act requires states to address cross-state air pollution that affects downwind states' ability to attain and maintain the National Ambient Air Quality Standards (NAAQS) through section 110(a)(2)(D)(i)(I) (also called the “good neighbor” provision). This section requires each state in its State Implementation Plan (SIP) to prohibit emissions that will contribute significantly to nonattainment of a NAAQS, or interfere with maintenance of a NAAQS, in a downwind state. The Act requires EPA to promulgate Federal Implementation Plans (FIPs) in the event that states fail to submit or submit inadequate good neighbor SIPs.
Clean Air Act Section 126
Section 126 of the Clean Air Act gives a state the authority to ask EPA to set emissions limits for specific sources of air pollution in other states that significantly contribute to nonattainment or interfere with maintenance of one or more National Ambient Air Quality Standards in the petitioning state. The Clean Air Act requires the EPA to respond to these types of petitions within 60 days of receipt.
Clean Air Act Section 176A
Section 176A provides that, when the EPA Administrator has reason to believe that the interstate transport of air pollutants from one or more states contributes significantly to a violation of the NAAQS in one or more other states, they may establish a transport region comprised of those states to address such pollution. Under this provision, the Administrator may also add any state (or portion thereof) to a transport region to address cross-state air pollution. When the Administrator establishes an ozone transport region, they shall also establish an associated transport commission to assess the degree of cross-state air pollution and identify control strategies to mitigate it.
Clean Air Act Section 184
Section 184 of the Clean Air Act itself established a single transport region for ozone—the Ozone Transport Region—covering portions of the northeast and mid-Atlantic. This section also specifies control requirements to address cross-state pollution of ozone within the region.
The Ozone Transport Commission is a multi-state organization responsible for advising EPA on cross-state air pollution issues within this region and for developing and implementing regional solutions to the ground-level ozone problem in the Northeast and Mid-Atlantic regions.
- See the Plain English Guide to the Clean Air Act for more information.