Page:Michigan v. EPA.pdf/35

 Cite as: 576 U. S. ____ (2015)

13

KAGAN, J., dissenting

Even after establishing multiple floor standards that factored in costs, EPA adopted additional “compliance options” to “minimize costs” associated with attaining a given floor—just as its “appropriate and necessary” finding explicitly contemplated. Id., at 9306; 76 Fed. Reg. 25057; see 65 Fed. Reg. 79830. For example, the Agency calculated each floor as both an “input-based” standard (based on emissions per unit of energy used) and an “output-based” standard (based on emissions per unit of useful energy produced), and allowed plants to choose which standard they would meet. That option, EPA explained, can “result in. . . reduced compliance costs.” 76 Fed. Reg. 25063. Similarly, EPA allowed plants to meet a given 12% floor by averaging emissions across all units at the same site, instead of having to meet the floor at each unit. Some plants, EPA understood, would find such averaging a “less costly alternative.” 77 Fed. Reg. 9385. Yet again: EPA permitted “limited use” plants—those primarily burning —————— did not consider costs separate and apart from all other factors in crafting categories and subcategories. See S. Rep. No. 101–128, p. 166 (1989) (noting that EPA may not make classifications decisions “based wholly on economic grounds”); 77 Fed. Reg. 9395 (citing Senate Report). That approach could have subverted the statutory scheme: To use an extreme example, it would have allowed EPA, citing costs of compliance, to place the top few plants in one category, the next few in another category, the third in a third, and all the way down the line, thereby insulating every plant from having to make an appreciable effort to catch up with cleaner facilities. But in setting up categories and subcategories, EPA did consider technological, geographic, and other factors directly relevant to the costs that diverse power plants would bear in trying to attain a given emissions level. (For some reason, the majority calls this a “carefully worded observation,” ante, at 13, but it is nothing other than the fact of the matter.) The Agency’s categorization decisions (among several other measures, see supra, at 10–11; infra this page and 14) thus refute the majority’s suggestion, see ante, at 11, that the “appropriate and necessary” finding automatically generates floor standards with no relation to cost. To the contrary, the Agency used its categorization authority to establish different floor standards for different types of plants with different cost structures.