here, but nothing in section 107(d)(1) prevents EPA from developing general principles to govern its exercise of discretion when the time comes, or from announcing those general principles before the states submit their initial designations. To the extent petitioners think that EPA owes the states a measure of substantive deference under section 107(d)(1) — a claim that seems implicit in their objection that the C/MSA presumption somehow alters states’ “burden” in the designation process, see States’ Opening Br. 24 — we disagree. Though EPA may, of course, go along with states’ initial designations, it has no obligation to give any quantum of deference to a designation that it “deems necessary” to change. See, e.g., Pa. Dep’t of Envtl. Prot. v. EPA 429 F.3d 1125, 1129 (D.C.Cir.2005) (<HOLDING>). In short, EPA had authority to apply the
recognizing that board of immigration appeals should be accorded chevron deference as it gives ambiguous statutory terms concrete meaning through a process of casebycase adjudication holding regulations entitled to chevron deference recognizing that section 107d gives deference to states initial designations provided epa deems no modification necessary holding that a trial courts statutory interpretation is given no deference on review holding that the bia should be accorded chevron deference as it gives ambiguous statutory terms concrete meaning through a process of casebycase adjudication