Cite as: 540 U. S. 461 (2004)
Opinion of the Court
erators not subject to BACT. Id., at 111-112.20 By that
time, only MG-17 was "part of the permit action." Id., at 111, 199.
B
We emphasize that today's disposition does not impede ADEC from revisiting the BACT determination in question. In letters and orders throughout the permitting process, EPA repeatedly commented that it was open to ADEC to prepare "an appropriate record" supporting its selection of Low NOx as BACT. Tr. of Oral Arg. 35; see App. 127 (attachment to Sept. 28, 1999, EPA letter to ADEC, stating "an analysis of whether requiring Cominco to install and operate [SCR] would have any adverse economic impacts upon Cominco specifically" might demonstrate SCR's economic infeasibility); id., at 150 (letter accompanying EPA's Dec. 10, 1999, finding of noncompliance and order reiterating the Agency's willingness to "review and consider any additional information or analyses provided by ADEC or Cominco" on Low NOx as BACT); App. to Pet. for Cert. 36a (EPA Dec. 10, 1999, order inviting ADEC to justify its choice of Low NOx by "document[ing] why SCR is not BACT [for MG-17]"); id., at 49a (similar statement in Feb. 8, 2000, order). At oral argument, counsel for EPA reaffirmed that, "absolutely," ADEC could reconsider the matter and, on an "appropriate
20 The May 4, 1999, draft permit considered whether adding Low NOx to seven generators would result in lower emissions than adding SCR to only two and choosing one of the latter as a standby unit. App. 86-87. Before December 10, 1999, however, Cominco agreed to install Low NOx controls on four of the mine's six existing generators—MG-1, MG-3, MG-4, and MG-5—in order to increase use of those generators without exceeding the 1994 PSD permit's operating restriction. Id., at 149. Having agreed to use Low NOx on four generators, Cominco could propose in the December 10, 1999, permit only the addition of Low NOx to two generators—MG-2 and MG-6—to offset increases in emissions from MG- 17. No facts in the record support any suggestion that addition of Low NOx to three generators, MG-2, MG-6, and MG-17, would result in lower aggregate emissions than the addition of SCR to MG-17 alone.
501
Page: Index Previous 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 NextLast modified: October 4, 2007