Full-Scale Operating Experience with a Biological Phosphorus and Nitrogen Removal System Treating High-Strength Potato Processing Wastewater

McCain Foods operates a potato processing facility in Plover, Wisconsin, that produces a variety of potato products. Wastewater from this facility is treated onsite prior to discharge to the Wisconsin River. In 1993, the Wisconsin Department of Natural Resources promulgated a new categorical standard for total phosphorus (TP) on all discharges to the state's receiving waters. The Plover facility was the first industrial facility in the state subject to this rule and successfully negotiated a 6 mg/L TP limit contingent on the use of biological phosphorus removal (BPR) rather than physical/chemical phosphorus treatment alone.This paper discusses aspects of the implementation of a BPR process from pilot testing through full-scale design and implementation, startup, and ongoing operation of the system. Each phase provided insight into important considerations when designing and implementing this type of system. The wastewater treatment plant is currently able to consistently meet its effluent permit requirements within a very dynamic industrial environment. The Plover facility produces a variety of products that result in fluctuations in influent chemical oxygen demand (COD) loading including periodic planned facility shutdowns.