Opinion ID: 621128
Heading Depth: 4
Heading Rank: 1

Heading: New Source Performance Standards (NSPS)

Text: The EPA rejected Montana's fluid modeling calculation of GEP stack height because, even though it used NSPS for the modeling, the SIP did not actually require Montana Sulphur to meet the NSPS emission rate. 67 Fed.Reg. at 22,209. Montana Sulphur concedes that NSPS may be used for modeling purposes, but contends that NSPS cannot be used as a substantive emissions limit, noting that the EPA regulations themselves state that the allowable emission rate to be used in making demonstrations under this part shall be prescribed by the [NSPS] that is applicable to the source category. . . . 40 C.F.R. § 51.100(kk)(1) (emphasis added). The EPA's interpretation of its own regulation, however, is not unreasonable. The EPA explains that allowable emissions is a term of art it uses to denote an enforceable emission limit, not a mere assumed emission rate that may be disregarded later. The EPA claims it has always interpreted this language to require ongoing compliance with the NSPS, and notes that the term is used elsewhere in the stack height regulations as a substantive limit. 67 Fed.Reg. at 22,210. The EPA further points out that § 51.100(kk)(1) allows a source to demonstrate that the NSPS emission rate is infeasible, and that there would be no reason to include this provision if the NSPS rate were a mere assumption in fluid modeling that need never actually be met. 67 Fed.Reg. at 22,212. We must review the provision as a whole and, where possible, effectuate every word. See Boise Cascade Corp. v. EPA, 942 F.2d 1427, 1432 (9th Cir.1991). The EPA's interpretation is also consistent with the views expressed in the preamble to the EPA stack height regulations, which states that the applicable section has been revised . . . to specify that an emission rate equivalent to NSPS must be met before a source may conduct fluid modeling to justify stack height credit in excess of that permitted by the GEP formulae. 50 Fed.Reg. 27,892, 27,898 (July 8, 1985) (emphasis added); see Las Vegas v. FAA, 570 F.3d 1109, 1117 (9th Cir.2009) (if regulation is ambiguous, we consult the preamble of the final rule as evidence of context or intent of the agency promulgating the regulations). Our conclusion is also consistent with that of the D.C. Circuit, which addressed the issue of stack height and the use of NSPS and concluded that the EPA has the discretion to impose NSPS requirements in the above formula context. Natural Res. Def. Council, Inc. v. Thomas, 838 F.2d 1224, 1241 (D.C.Cir.1988). The court noted that above-formula credit should be granted with the utmost caution and that the selection of the NSPS baseline was consistent with this admonition. Id. (internal quotation marks omitted). In light of the foregoing, we conclude it was neither arbitrary nor capricious for the EPA to require the SIP to include NSPS limits consistent with the modeling demonstration. [5]