The following definitions apply for the purposes of this subpart. All terms not defined herein will have the meaning given them in § 51.100 or in the Clean Air Act (CAA). Air agency means the agency or organization responsible for air quality management within a state, local governmental jurisdiction, territory or area subject to tribal government. Annual SO2 emissions data means the quality-assured annual SO2 emissions data for a stationary source. Such data may have been required to be reported to the EPA in accordance with an existing regulatory requirement (such as the Air Emissions Reporting Rule or the Acid Rain Program); however, annual SO2 emissions data may be obtained or determined through other reliable means as well.

Applicable source means a stationary source that is:

(1) Not located in a designated nonattainment area, and

(2) Has actual annual SO2 emissions data of 2,000 tons or more, or has been identified by an air agency or by the EPA Regional Administrator as requiring further air quality characterization. 2010 SO2 NAAQS means the primary National Ambient Air Quality Standard for sulfur oxides (sulfur dioxide) as codified at 40 CFR 50.17, as effective August 23, 2010.