Custer State Park is responsible for treatment of wastewater flows from the Sylvan Lake Resort and the surrounding region. Banner’s design of the first Submerged Attached Growth Reactor (SAGR) in the state replaced their sand filter polishing process. The SAGR follows a two-cell stabilization pond system and provides low-maintenance polishing of the wastewater prior to discharge. The SAGR process is capable of ammonia removal even during cold climate operation. Banner performed extensive research on three polishing process options downstream of the ponds, ultimately selecting the SAGR system. Test data from December 2013 to February 2014 show ammonia-nitrogen levels ahead of the SAGR process from 1.66 to 5.43 mg/L (as Nitrogen). Following the SAGR, ammonia-nitrogen levels were 0.050 to 0.064 mg/L (as Nitrogen) with 6°C water temperatures. In addition to the SAGR reactors, the facility improvements included flow distribution process piping, equalization, ball cover for algae control, and compressors housed in an enclosure to support the SAGR system. 

Project Goal #1

Reliably meet Surface Water Discharge Limits for BOD5, TSS, Ammonia, and coliform

Project Goal #2

Replace a failed fine sand filtrations system

Project Goal #3

Treatment process needed to be easy to operate due to remote location