STATE OF WISCONSIN DEPARTMENT OF NATURAL

Published May 19, 2023 at 1:25 AM

STATE OF WISCONSIN DEPARTMENT OF NATURAL RESOURCES PUBLIC NOTICE OF INTENT TO REISSUE A WISCONSIN POLLUTANT DISCHARGE ELIMINATION SYSTEM (WPDES) PERMIT No.WI-0063053-04-0 Permittee: GREATER BAYFIELD WWTP COMMISSION, P O Box 1170, Bayfield, WI, 54814 Facility Where Discharge Occurs: Greater Bayfield WWTP Commission, 85025 OLD SAN ROAD, BAYFIELD, WISCONSIN Receiving Water And Location: A dry run tributary to Lake Superior within the Bayfield Peninsula Southeast Watershed in the Lake Superior Drainage Basin in Bayfield County Brief Facility Description and Summary of Proposed Changes: The Greater Bayfield Wastewater Treatment Plant Commission (GBWTPC) owns and operates the Greater Bayfield Wastewater Treatment Plant. The plant serves the City of Bayfield and Pikes Bay Sanitary District and is designed to perform at a level which exceeds state and federal standards. Minnesota, Wisconsin, Michigan and Ontario identified Lake Superior as a zero discharge demonstration zone. The GBWTPC has agreed to provide a higher level of treatment to protect the water quality of Lake Superior. The Greater Bayfield WWTP Commission plant designed to treat 300,000 gallons per day, currently treats an average of 125,000 gallons per day (2018-2022 data). Effluent is discharged year-round. The facility includes a mechanical bar screen followed by an anaerobic tank and oxidation ditches. Organic material in the wastewater is treated aerobically in the oxidation ditches through the activated sludge process. The system is also designed for biological phosphorous removal (BPR) and denitrification. BPR is a process that uses alternating anaerobic and aerobic zones to provide an environment that encourages uptake of phosphorous by specialized microorganisms which are eventually removed with waste activated sludge (WAS). Chemical (alum) addition is also used as needed to ensure compliance with phosphorous limits. The oxidation ditches include mixed anoxic zones to promote denitrification. Final clarifiers allow solids to settle out of the wastewater prior to additional filtration. Cloth disk filtration further polishes the wastewater, allowing the plant to reach its goals of