Opinion ID: 4020089
Heading Depth: 2
Heading Rank: 8

Heading: gact standard determinations

Text: With few exceptions, the EPA has broad discretion to choose how to control area source emissions. For instance, the EPA has discretion to choose between GACT and MACT standards in the majority of cases. See 42 U.S.C. § 7412(d)(5). Even if the EPA chooses a MACT standard, it has discretion—although somewhat circumscribed—to set a work-practice standard instead of a numeric standard. Id. § 7412(h)(1). And the EPA has discretion when choosing among different GACT-standard options. See id. § 7412(d)(5). Accordingly, we must uphold the EPA’s GACT-standard determinations so long as it “has considered the relevant factors and articulated a rational connection between the facts found and the choice made, and has not relied on [improper] factors.” Nat’l Ass’n of Clean Air Agencies, 489 F.3d at 1228 (citations and internal quotation marks omitted). But for all of the discretion the EPA enjoys, it must nonetheless demonstrate that it exercised its judgment in a reasoned way. 126 The cases establishing this principle are legion. See, e.g., Transactive Corp. v. United States, 91 F.3d 232, 236 (D.C. Cir. 1996) (agency must “identif[y] and explain[] the reasoned basis for its decision”); Int’l Fabricare Inst., 972 F.2d at 389 (agency must “examine[] the relevant data and . . . articulate[] an adequate explanation for its action”). The EPA need not go to great lengths to meet its burden; indeed, we “uphold a decision of less than ideal clarity” so long as “the agency’s path may reasonably be discerned.” State Farm, 463 U.S. at 43 (quoting Ark.-Best Freight Sys., Inc., 419 U.S. at 286). With these principles in mind, we address the Environmental Petitioners’ two challenges to the EPA’s discretionary decisions regarding the Area Boilers Rule.
for Non-Hg Metals The Environmental Petitioners argue that the EPA failed to support its decision-making when it established MACT standards for Hg and POM emissions from some coal-fired boilers but declined to regulate non-Hg emissions under the MACT standard from the same boilers. We agree. Although the EPA thoroughly explained why it chose to impose one GACT standard instead of another, nothing in the record explains why the EPA decided to impose GACT standards instead of MACT standards in the first place. Despite the Agency’s broad discretion, we cannot sustain its action in the absence of some explanation for why GACT standards are more appropriate than MACT standards for these sources and types of pollutants. See Transactive Corp., 91 F.3d at 236. For this reason, we remand (but do not vacate) the EPA’s choice of GACT standards for non-Hg emissions from coal127 fired boilers. See Sierra Club, 167 F.3d at 664; Nat’l Lime Ass’n, 233 F.3d at 634-35.
The Environmental Petitioners also challenge several of the EPA’s choices among different GACT standards. As noted, see supra § I.A.1.c, the CAA provides virtually no instruction regarding GACT standards but the standards generally take the form of “methods, practices and techniques which are commercially available and appropriate for application by the sources in the category considering economic impacts and the technical capabilities of the firms to operate and maintain the emissions control systems.” S. REP. NO. 101-228, at 171 (1989). Because the EPA has ample discretion to choose the appropriate GACT standard, we will affirm its choices so long as we can discern reasoned decision-making from the record. State Farm, 463 U.S. at 43. For the reasons set forth below, we can do so here and, accordingly, we reject the Environmental Petitioners’ GACTfocused challenges. First, the Environmental Petitioners challenge the data set the EPA used to arrive at the numeric GACT standards for non-Hg-metal emissions from coal-fired boilers. Specifically, they contend that the EPA set the GACT limit based on boilers with no control technology, which resulted in a numeric standard of 0.42 lb/mmBtu. They insist that the EPA should instead have examined boilers outfitted with fabric filters, which would have resulted in a numeric standard of 0.03 lb/mmBtu. The EPA, however, thoroughly explained why it considered the uncontrolled boiler data set. Specifically, the controlled data set derives from the EPA’s “New Source Performance Standards” (NSPS) data, which, in 128 the Agency’s view, could be used to set the non-Hg-metal GACT standard for boilers with a heat input capacity of 30 mmBtu/hr or greater but did not suffice for boilers with a lower heat input capacity. For this reason, the EPA examined its original data set, found that none of the coal-fired boilers in that set used control technology and, accordingly, set the GACT numeric standard at the emissions level achieved by the best performing uncontrolled source in that data set (i.e., 0.42 lb/mmBtu). We are satisfied that the EPA exercised its discretion in a reasoned manner and, accordingly, we do not disturb it. See Transactive Corp., 91 F.3d at 236. Next, the Environmental Petitioners challenge the EPA’s decision to establish a tune-up requirement as a GACT management-practice standard for Hg and POM emissions from large biomass-fired and oil-fired boilers. In their view, other, more restrictive control technologies, including multiclones,38 are “generally available” and their availability mandates that the EPA set numeric standards based on boilers that use those controls. But the EPA explained its approach: A boiler tune-up requirement would potentially result in the same non-mercury metallic HAP reduction as a PM emission limit based on performance of multiclones but would also reduce emissions of organic HAP. In addition the cost of a boiler tune-up appears minimal compared to the cost for testing and 38 A multiclone is a PM “mechanical separator[].” See 2010 Proposed Area Boilers Rule, 75 Fed. Reg. at 31,908. It diverts particles from the exhaust stream by creating a circular air flow. See id. 129 monitoring to demonstrate compliance with an emission limit. See 2010 Proposed Area Boilers Rule, 75 Fed. Reg. at 31,908. The EPA also explained that multiclones were “minimally effective” for controlling non-Hg metals, ineffective for POM and Hg, and expensive. Id. Because the EPA’s decision to impose a tune-up requirement fits within its “technical expertise,” we owe the Agency an “extreme degree of deference” so long as its explanation is rational. Catawba Cty., N.C. v. EPA, 571 F.3d 20, 41 (D.C. Cir. 2009) (quoting City of Waukesha v. EPA, 320 F.3d 228, 247 (D.C. Cir. 2003)). And because its explanation was rational, we reject the Petitioners’ challenge thereto. Finally, the Petitioners challenge the EPA’s decision to set a tune-up requirement as a management-practice standard for small biomass-fired and oil-fired area boilers. The EPA adopted this approach because measuring PM emissions for smaller boilers is “not feasible.” 2010 Proposed Area Boilers Rule, 75 Fed. Reg. at 31,906. When the EPA explained its decision regarding small biomass-fired and oil-fired area boilers, it provided the same reasons it gave for its use of a tune-up requirement for small coal-fired area boilers, which we address (and uphold), infra, § IV.M. For those reasons, we reject the challenge to the EPA’s tune-up requirement for small biomass-fired and oil-fired area boilers.