By Glen Hansen
The Clean Air Act (“CAA”) charges the United States Environmental Protection Agency (“EPA”) with setting National Ambient Air Quality Standards (“NAAQS”), which prescribe the maximum permissible levels of common pollutants in the ambient air. EPA designates “nonattainment” areas — that is, areas within each State where the level of the pollutant exceeds the NAAQS. Once EPA sets a NAAQS and designates nonattainment areas within the States, the lead role shifts to the States. The States implement the NAAQS within their borders through State Implementation Plans (“SIPs”). In their SIPs, States choose which individual sources within the State must reduce emissions, and by how much. States must submit SIPs to EPA within three years of each new or revised NAAQS. One of the required elements of a SIP submission is the “good neighbor” provision, which recognizes that emissions from “upwind” regions may pollute “downwind” regions. The good neighbor provision requires upwind States to bear responsibility for their fair share of the nonattainment in downwind States. EPA plays the critical role in gathering information about air quality in the downwind States, calculating each upwind State’s good neighbor obligation, and transmitting that information to the upwind State. With that information, the upwind State can then determine how to meet its good neighbor obligation in a new SIP or SIP revision. If a State does not timely submit an adequate SIP (or an adequate SIP revision) to take account of the good neighbor obligation as defined by EPA, responsibility shifts back to the Federal Government. Within two years of disapproving a State’s SIP submission or SIP revision, or determining that a State has failed to submit a SIP, EPA must promulgate a Federal Implementation Plan (“FIP”) to implement the NAAQS within that State.