P’s withdrawals and discharges of water for its power plant are regulated by the Clean Water Act (CWA). The water that P discharges has elevated temperatures. For the last three decades, these actions have been authorized by a series of NPDES permits issued by the EPA. In 1998, P applied for renewal of its NPDES permit and thermal variance authorization. The EPA rejected the requested thermal variance. P sought review before the Environmental Appeals Board and asked for an evidentiary hearing. The Board accepted the petition for review but declined to convene an evidentiary hearing. P notified the EPA of its intent to file a citizen's suit to compel the Board to hold an evidentiary hearing. P filed suit, and the EPA moved to dismiss. The district concluded that it was without subject matter jurisdiction because the suit, though billed as a citizen's suit, constituted a direct challenge to the EPA's hearing rule and, thus, came within the exclusive jurisdiction of the circuit court under 33 U.S.C. § 1369(b)(1)(E). P appealed.