The City of Lowell, Massachusetts (“City”) petitioned the Environmental Appeals Board (“Board”) to review a National Pollutant Discharge Elimination System (“NPDES”) permit that the United States Environmental Protection Agency Region 1 (“Region”) issued to the City pursuant to the Clean Water Act. The permit authorizes the City to discharge wastewater effluent from its regional wastewater treatment facility and several combined sewer overflow outfalls into the Merrimack River and two nearby tributaries. The permit on which the City seeks review is a renewal of a permit issued in 2005.