PSCO filed an application with D for permission to discharge heated water into the Hampton-Seabrook Estuary. The temperature would be 39 degrees F higher than at intake. The FWPCA, 33 U.S.C. § 1311(a), prohibits the discharge of any pollutant unless the discharger, the point source operator, has obtained an EPA permit. Heat is a pollutant. PSCO applied not only for a discharge permit but also an exemption from the EPA standards. Under § 316(a) a point source operator who 'after opportunity for public hearing, can demonstrate to the satisfaction of the Administrator' that the EPA's standards are 'more stringent than necessary to assure the protection and propagation of a balanced, indigenous population of shellfish, fish, and wildlife in and on the body of water' may be allowed to meet a lower standard. Hearings were held in March and April, pursuant to D's regulations establishing procedures for deciding applications for permits under § 402 of the FWPCA. PSCO's application was eventually denied. PSCO appealed the decision, and a new Administrator was appointed, and he assembled a panel of six in-house advisors to assist in his technical review. They met and submitted a report finding that with one exception, PSCO had met its burden of proof. The Administrator asked PSCO to submit further information, offered other parties the opportunity to comment. P did request a hearing, but the Administrator denied the request. The Regional Administrator's decision was reversed, and P appealed.