Wisconsin Electric Power d/b/a We Energies on July 7 requested authorization from the Wisconsin Public Service Commission to replace a wastewater treatment system at its Pleasant Prairie Power Plant that treats the plant’s coal pile runoff, metal cleaning wastewater and low volume wastewater.
This project, at an estimated cost of $14m, will replace the existing, clarifier-based wastewater treatment system with a modern ultrafiltration (UF) system. The new system will be housed in the existing treatment building.
Pleasant Prairie, located in the village of Pleasant Prairie, Kenosha County, consists of two fossil-fueled units, each with a pulverized-coal-fired boiler and steam turbine generator. Unit 1 was placed in service in 1980 with Unit 2 following in 1985. Each unit has a net summer rating of 600 MW.
Pleasant Prairie currently treats coal pile runoff, non-chemical metal cleaning wastewater, and low volume wastewater using a conventional physical-chemical wastewater treatment system consisting of coagulation/flocculation, clarification, filtration, and pH adjustment steps. The existing treatment system consists of a reaction tank with chemical addition (polymer and sodium hydroxide), two reactor clarifiers, a media filter, and a clearwell with pH adjustment.
This treatment system equipment, original to the plant, is at the end of its life-cycle. The clarifiers, pumps, piping, valves, and sluice gates for the system are in poor condition and require frequent maintenance, the utility noted. The treatment system has process limitations which have caused the storage basins to reach capacity and risk overtopping.
The utility hopes to have the new system built by the end of March 2015 and fully operating by the end of May 2015.