existing OCS source
(4) Definitions For purposes of subsections (a) and (b)— (A) Outer Continental Shelf The term “Outer Continental Shelf” has the meaning provided by section 2 of the Outer Continental Shelf Lands Act ( 43 U.S.C. 1331 ). (B) Corresponding onshore area The term “corresponding onshore area” means, with respect to any OCS source, the onshore attainment or nonattainment area that is closest to the source, unless the Administrator determines that another area with more stringent requirements with respect to the control and abatement of air pollution may reasonably be expected to be affected by such emissions. Such determination shall be based on the potential for air pollutants from the OCS source to reach the other onshore area and the potential of such air pollutants to affect the efforts of the other onshore area to attain or maintain any Federal or State ambient air quality standard or to comply with the provisions of part C of subchapter I. (C) Outer Continental Shelf source The terms “Outer Continental Shelf source” and “OCS source” include any equipment, activity, or facility which— (i) emits or has the potential to emit any air pollutant, (ii) is regulated or authorized under the Outer Continental Shelf Lands Act [ 43 U.S.C. 1331 et seq.], and (iii) is located on the Outer Continental Shelf or in or on waters above the Outer Continental Shelf. Such activities include, but are not limited to, platform and drill ship exploration, construction, development, production, processing, and transportation. For purposes of this subsection, emissions from any vessel servicing or associated with an OCS source, including emissions while at the OCS source or en route to or from the OCS source within 25 miles of the OCS source, shall be considered direct emissions from the OCS source. (D) New and existing OCS sources The term “new OCS source” means an OCS source which is a new source within the meaning of section 7411(a) of this title . The term “existing OCS source” means any OCS source other than a new OCS source.