Opinion ID: 621128
Heading Depth: 3
Heading Rank: 2

Heading: Flare Emissions

Text: The EPA also disapproved the revised Montana SIP in part because it failed to include any numerical emissions limits on flares. Flaring is a practice that provides for equipment to immediately release gases to a device (a flare) for incineration. It is used in emergencies (malfunctions) and some routine circumstances, such as startup, shutdowns and maintenance (collectively, SSM). Montana included an emission rate assumption for each flare in its attainment demonstration, assuming limitations of 150 pounds of SO2 per 3-hour period. [6] However, in its revised SIP, Montana imposed instead a work practice standard during SSM that required best practices be used to minimize flaring, and eliminated any numerical emission limitations on flares. Montana concluded it was technically infeasible to regulate flares through numerical limits, but agreed with the EPA that the SIP is incomplete without enforceable emission limitations applicable to flares, and that such limitations should correspond to the emission rates used in the attainment demonstrations. Disapproval of the SIP was not arbitrary or capricious in these circumstances. Under the EPA's regulations, a proposed SIP must demonstrate that the measures, rules, and regulations contained in it are adequate to provide for the timely attainment and maintenance of the national standard that it implements. 40 C.F.R. § 51.112(a); see also Hall v. EPA, 273 F.3d 1146, 1158 n. 8 (9th Cir.2001) (An `attainment demonstration' is a formal demonstration . . . that the pollution control measures contained in an implementation plan are adequate to provide for the timely attainment and maintenance of NAAQS.). Here, Montana demonstrated the control strategies contained in the SIP plus a 150 lb/3-hour limit on flares would attain the NAAQS. The SIP itself, however, was missing the second part of the equation. Although Montana Sulphur contends flaring is not a significant source of SO2 emissions, the EPA points to modeling evidence that the flare emissions likely were significant (219 tons/year/source)well above the 100 tons/year threshold that can trigger major source permitting requirements. 67 Fed.Reg. at 22,182. Flare emissions can affect attainment, and limits on them reasonably can be required, particularly where the state has relied on such limits to demonstrate attainment. See Michigan Dep't of Envtl. Quality v. Browner, 230 F.3d 181 (6th Cir.2000) (holding EPA properly disapproved Michigan SIP revision that permitted automatic exemption for source that violates emissions standards if violation results from SSM and meets other standards). Note that at this point, we consider only whether the EPA acted rationally in disapproving the SIP for failing to include emission limitations that were otherwise part of the state's attainment demonstration. We discuss in further detail below, in the context of the FIP, whether the EPA can rationally limit flaring during SSM periods.