Opinion ID: 676032
Heading Depth: 2
Heading Rank: 1

Heading: Regulation of Marine Vessels

Text: 15 Each party argues that Congress has directly spoken to the in transit issue and that the text of section 328 unambiguously supports its position. Thus the County argues that the EPA's construction is owed no deference, while the EPA asserts that none is necessary. The County contends that the language of subsection (a)(1) requires the Administrator to control air pollution from Outer Continental Shelf sources, which it interprets to include marine vessels in transit, in the same manner as if the source were located in the corresponding onshore area. 42 U.S.C. Sec. 7627(a)(1). The EPA, on the other hand, maintains that the definition of OCS source in subsection (a)(4)(C) makes clear that marine vessels in transit are excluded. See id. Sec. 7627(a)(4)(C). 16 The County's position would be unassailable if vessels in transit were unambiguously included within the statutory meaning of Outer Continental Shelf sources. Yet as the EPA points out, that phrase is defined in subsection (a)(4), which mentions vessels in only two contexts: drill ship exploration and 17 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. 18 Id. Sec. 7627(a)(4)(C) (emphasis added). The definitional provision thus fails to make specific mention of vessels in transit. We do not find this silence to be dispositive; rather, we view the provision as ambiguous, at least insofar as the status of vessels in transit is concerned. The agency defines OCS source to include vessels only when they are: 19 (1) Permanently or temporarily attached to the seabed and erected thereon and used for the purpose of exploring, developing or producing resources therefrom, within the meaning of section 4(a)(1) of OCSLA (43 U.S.C. Sec. 1331 et seq.); or 20 (2) Physically attached to an OCS facility, in which case only the stationary source aspects of the vessels will be regulated. 21 40 C.F.R. Sec. 55.2 (1993). We find this to be a permissible reading of the statute: As section 7627 merely mentions vessels servicing or associated with an OCS source to ensure their emissions are included with those of the parent OCS source (when the vessel is within 25 miles of the source, and is en route to or from the source), we find it was reasonable for the EPA to conclude that OCS sources did not include vessels that were merely traveling over the OCS. We therefore accord the agency's interpretation the deference that it is due under Chevron.