In Re the Cities of Annandale & Maple Lake NPDES/SDS Permit Issuance for the Discharge of Treated Wastewater

*506OPINION

ANDERSON, PAUL H„ Justice.

This appeal results from the issuance of a National Pollutant Discharge Elimination System (NPDES) permit by the Minnesota Pollution Control Agency (MPCA) for a wastewater treatment plant jointly proposed by the City of Annandale and the City of Maple Lake (the Cities). The MPCA found that the proposed plant — when operating at capacity — would increase phosphorus discharge to the North Fork of the Crow River by approximately 2,200 pounds per year over that which is discharged by the Cities’ existing facilities, but the MPCA concluded that, under 40 C.F.R. §…