For 30 years, the Environmental Protection Agency (EPA) (defendant) had issued a series of National Pollution Discharge Elimination System (NPDES) permits under the Clean Water Act (CWA), 33 U.S.C. §§ 1251-1387. These permits authorized Dominion Energy Brayton Point, LLC (Dominion) (plaintiff) to use a cooling system for its electrical plant. The plant’s cooling system pulled water from two rivers and discharged warmed water into a bay. The standards in the NPDES permits were set according to the thermal-variance procedures outlined in § 316(a) of the CWA. After Dominion applied to renew its NPDES permit in 1998, the EPA issued a proposed final NPDES permit in 2003 that rejected the plant’s requested thermal variance. The EPA issued a final rule eliminating formal evidentiary hearings from the NPDES permitting process. Dominion petitioned for review by the EPA’s Environmental Appeals Board (Board), which granted the petition but denied Dominion’s request for an evidentiary hearing. Dominion filed suit against the EPA in federal district court, arguing that the EPA was required to grant its request for a formal evidentiary hearing. The district court dismissed the case. Dominion appealed to the United States Court of Appeals for the First Circuit, seeking a determination that the EPA was required by First Circuit precedent to grant the requested hearing.