Cite as: 503 U. S. 91 (1992)
Opinion of the Court
contrary to those actually made by the ALJ. 908 F. 2d, at 620, 625, 627, 629. Although we have long recognized the "substantial evidence" standard in administrative law, the court below turned that analysis on its head. A court reviewing an agency's adjudicative action should accept the agency's factual findings if those findings are supported by substantial evidence on the record as a whole. See generally Universal Camera Corp. v. NLRB, 340 U. S. 474 (1951). The court should not supplant the agency's findings merely by identifying alternative findings that could be supported by substantial evidence.
Third, the court incorrectly concluded that the EPA's decision was arbitrary and capricious. This error is derivative of the court's first two errors. Having substituted its reading of the governing law for the Agency's, and having made its own factual findings, the Court of Appeals concluded that the EPA erred in not considering an important and relevant fact—namely, that the upper Illinois River was (by the court's assessment) already degraded.
As we have often recognized, an agency ruling is "arbitrary and capricious if the agency has . . . entirely failed to consider an important aspect of the problem." Motor Vehicle Mfrs. Assn. of United States, Inc. v. State Farm Mut. Automobile Ins. Co., 463 U. S. 29, 43 (1983). However, in these cases, the degraded status of the river is only an "important aspect" because of the Court of Appeals' novel and erroneous interpretation of the controlling law. Under the EPA's interpretation of that law, what matters is not the river's current status, but rather whether the proposed discharge will have a "detectable effect" on that status. If the Court of Appeals had been properly respectful of the Agency's permissible reading of the Act and the Oklahoma standards, the court would not have adjudged the Agency's decision arbitrary and capricious for this reason.
In sum, the Court of Appeals made a policy choice that it was not authorized to make. Arguably, as that court sug-
113
Page: Index Previous 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 NextLast modified: October 4, 2007