This matter is before the Environmental Appeals Board (“Board”) on appeal by USGen New England, Inc. (“USGen” or “Petitioner”) from a final National Pollutant Discharge Elimination System permit decision issued under the Clean Water Act (“CWA” or “Act”), 33 U.S.C. §§ 1251-1387, by Region I (“Region”) of the United States Environmental Protection Agency (“EPA” or “Agency”). The Region issued the permit decision, NPDES Permit No. MA 0003654, on October 6, 2003, for USGen’s power plant at Brayton Point Station in Massachusetts.