Cite as: 528 U. S. 167 (2000)
Opinion of the Court
B
Satisfied that FOE had standing under Article III to bring this action, we turn to the question of mootness.
The only conceivable basis for a finding of mootness in this case is Laidlaw's voluntary conduct—either its achievement by August 1992 of substantial compliance with its NPDES permit or its more recent shutdown of the Roebuck facility. It is well settled that "a defendant's voluntary cessation of a challenged practice does not deprive a federal court of its power to determine the legality of the practice." City of Mesquite, 455 U. S., at 289. "[I]f it did, the courts would be compelled to leave '[t]he defendant . . . free to return to his old ways.' " Id., at 289, n. 10 (citing United States v. W. T. Grant Co., 345 U. S. 629, 632 (1953)). In accordance with this principle, the standard we have announced for determining whether a case has been mooted by the defend-ant's voluntary conduct is stringent: "A case might become moot if subsequent events made it absolutely clear that the allegedly wrongful behavior could not reasonably be expected to recur." United States v. Concentrated Phosphate Export Assn., Inc., 393 U. S. 199, 203 (1968). The "heavy burden of persua[ding]" the court that the challenged conduct cannot reasonably be expected to start up again lies with the party asserting mootness. Ibid.
The Court of Appeals justified its mootness disposition by reference to Steel Co., which held that citizen plaintiffs lack standing to seek civil penalties for wholly past violations. In relying on Steel Co., the Court of Appeals confused mootness with standing. The confusion is understandable, given this Court's repeated statements that the doctrine of mootness can be described as "the doctrine of standing set in a time frame: The requisite personal interest that must exist at the commencement of the litigation (standing) must continue throughout its existence (mootness)." Arizonans for Official English, 520 U. S., at 68, n. 22 (quoting United States Parole Comm'n v. Geraghty, 445 U. S. 388, 397 (1980), in turn
189
Page: Index Previous 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 NextLast modified: October 4, 2007