Opinion ID: 858996
Heading Depth: 2
Heading Rank: 3

Heading: epa’s grant of a 500 meter ambient air

Text: EXEMPTION IS NOT PLAINLY ERRONEOUS OR INCONSISTENT WITH THE AGENCY ’S REGULATIONS In the revised air permits issued in September 2011, the EPA granted Shell’s request for a 500-meter radius “ambient air” exemption. The EAB, in its January 2012 decision, upheld this exemption, which allows Shell to assess compliance with air quality standards at a distance of 500 meters from the center of the drillship. In re: Shell Gulf of Mexico, 2012 WL 119962. Air quality impacts within the 500-meter radius are not subject to analysis or regulation. The exemption is contingent on the Coast Guard’s establishment of an effective safety zone precluding public access to the area, and Shell’s development and implementation of a public access program. According to the Supreme Court, “‘ambient air’ [] is the statute’s term for the outdoor air used by the general public.” Train v. NRDC, Inc., 421 U.S. 60, 65 (1975). Curiously, the Clean Air Act does not define “ambient air,” but the EPA’s regulations define the term as “that portion of the atmosphere, external to buildings, to which the general public has access.” 40 C.F.R. § 50.1(e). The agency has occasionally exempted certain areas from being labeled ambient air. The parties agree that the agency’s “longstanding interpretation” of this exemption is described in a 1980 letter from former EPA Administrator Douglas Costle. That letter states that an REDOIL V . EPA 19 “exemption from ambient air is available only for the atmosphere over land owned or controlled by the source and to which public access is precluded by a fence or other physical barriers.” The Supreme Court instructs that an agency’s interpretation of its own regulations is “controlling unless ‘plainly erroneous or inconsistent with the regulation.’” Auer v. Robbins, 519 U.S. 452, 461 (1997) (quoting Robertson v. Methow Valley Citizens Council, 490 U.S. 332, 359 (1989)). The relevant inquiry is whether the EPA’s grant of the ambient air exemption to Shell is plainly erroneous or inconsistent with its regulatory definition of ambient air. It is obvious that the exemption here is not “for the atmosphere over land owned or controlled by the source and to which public access is precluded by a fence or other physical barriers” (emphasis added). However, neither is the exemption inconsistent with the EPA’s regulatory definition of ambient air or clearly erroneous. The essence of the EPA’s regulatory definition links ambient air to public access. Because the EPA conditioned Shell’s permit and ambient air exemption on the establishment of an effective safety zone that precludes public access, the grant is consistent with the regulation. Further, the EPA has not impermissibly departed from its longstanding regulatory interpretation of “ambient air” without explanation or justification, as REDOIL claims. We are persuaded by the EAB’s reasonable explanation that Costle’s 1980 letter prescribing a fence or other physical barrier to preclude public access was “clearly written with overland situations in mind.” In re: Shell Gulf of Mexico, 2012 WL 119962, at . The agency did not have the 20 REDOIL V . EPA occasion to consider how it might apply the exemption in the context of open waters until ten years later, when Congress first gave the EPA jurisdiction to regulate air pollution from OCS sources. The EAB’s assessment that the agency “requires some leeway” in determining how to apply “the regulation and the interpretive letter to an ‘overwater’ situation” is just common sense. Id. Constructing a fence in the Arctic Ocean would make little sense, and the EPA has previously recognized a safety zone established by the Coast Guard as evidence of sufficient ownership or control over open water areas to qualify as a boundary for defining ambient air. Here, as in that precedent, the EPA imposed conditions that approximated the criteria in the Costle letter—control of property and limited public access—for a marine environment. We conclude that the EPA’s grant of an ambient air exemption to Shell conditioned on an effective safety zone excluding the public is a permissible interpretation of its ambient air regulation and earlier letter ruling. PETITION DENIED.