It provides for a regulatory scheme to protect and enhance the nation's air quality through joint federal and state participation with some responsibilities falling to the federal EPA and others to state agencies. See Sierra Club v. Georgia Power Co., 443 F.3d 1346, 1348 (11th Cir.2006) (citing 42 U.S.C. §§ 7401[b][1], 7410); accord Environmental Defense v. Duke Energy Corp., 549 U.S. 561, 566–67, 127 S.Ct. 1423, 167 L.Ed.2d 295 (2007); Southern Alliance for Clean Energy v. Duke Energy, 650 F.3d 401, 403–04 (4th Cir.2011). To achieve the CAA's goals, Congress established the maximum allowable increases and concentrations for some pollutants.

Thus, the award of fees and costs was appropriate. Though the matter in Hanson pre-dates Buckhannon , the Fourth Circuit reaffirmed its rationale in Southern Alliance For Clean Energy v. Duke Energy Carolinas, LLC. , 650 F.3d 401 (4th Cir. 2011). While interpreting the "whenever appropriate" language in the citizen suits provision of the Clean Air Act, 42 U.S.C. § 7604(d), the court stated there is "sufficient success to support attorneys' fees, for example, where an agency is ordered to carry out one of its regulatory duties such as adequately investigating complaints—regardless of the outcome of the investigation."

The Clean Air Act's attorney fee provision "was meant to expand the class of parties eligible for fee awards from prevailing parties to partially prevailing parties - parties achieving some success, even if not major success." Southern Alliance for Clean Energy v. Duke Energy Carolinas, LLC, 650 F.3d 401, 406 (4th Cir. 2011) (quoting Ruckelshaus, 463 U.S. at 688). To have achieved "some success," a plaintiff must have "obtained judicially enforceable actual relief on the merits of [its] claim that materially altered the legal relationship between the parties."

See House of Flavors, Inc. v. TFG-Michigan, L.P., 700 F.3d 33, 37 (1st Cir. 2012) (affirming bright-line rule in Budinich and holding request for attorney's fees authorized by statute or decisional law does not suspend finality of judgment on underlying claim); O & G Indus., Inc. v. Nat'l R.R. Passenger Corp., 537 F.3d 153, 168 n.11 (2d Cir. 2008) (holding the same and noting that this "sensible" bright-line rule "promotes the interests of judicial economy, especially in this case where resolution of the 'question remaining to be decided . . . will not alter . . . or revise' the court's final rulings on the merits of the other issues on appeal." (quoting Budinich, 486 U.S. at 199)); Budget Blinds, Inc. v. White, 536 F.3d 244, 251 (3rd Cir. 2008) ("The part of the District Court's Order vacating the default judgment is 'final' . . . despite the fact that the amount of attorneys' fees remains unresolved."); S. Alliance For Clean Energy v. Duke Energy Carolinas, LLC, 650 F.3d 401, 405-06 (4th Cir. 2011) (holding fee determinations are generally distinct from merits determinations, and the latter of which cannot generally be revisited on appeal of the former); Lindy Invs. v. Shakertown Corp., 209 F.3d 802, 805 (5th Cir. 2000) ("By separating the trial on the merits from the award of attorney's fees and costs, the trial court has created a two-track system for appeals purposes."); Armisted v. State Farm Mut. Auto. Ins. Co., 675 F.3d 989, 993 (6th Cir. 2012) (holding presence of outstanding claim for attorney's fees does not alter finality of judgment otherwise of all parties and issues); Elusta v. City of Chicago, 696 F.3d 690, 695 (7th Cir. 2012) (holding the same and distinguishing Budinich on other grounds); Tweedle v. State Farm Fire & Cas. Co., 527 F.3d 664, 669 (8th Cir. 2008) (holding the same); Or. Natural Desert Ass'n v. Locke, 572 F.3d 610, 614 (9th Cir. 2009) (holding the same); RMA Ventures Cal. v. SunAmerica Life Ins. Co., 576 F.3d 1070, 1073 (10th Cir. 2009) ("[A] decisio