Ephraim STP - Advanced Wastewater Treatment in Town of Liberty Grove, Wisconsin

Ephraim STP is a municipal wastewater treatment facility located in the Town of Liberty Grove, Door County, Wisconsin, on the Door Peninsula. The plant serves a population of approximately 3,417 residents and operates with advanced treatment processes, reflecting the community's commitment to protecting the sensitive coastal environment of Lake Michigan. With a designed capacity of 1,173.47 thousand cubic meters per year and an actual discharge volume of 529.96 thousand cubic meters per year, the plant operates well within its capacity. As a US facility, it is regulated under the Clean Water Act and operates under an NPDES permit issued by the Wisconsin Department of Natural Resources, which sets strict effluent limits to safeguard water quality. The plant's treated effluent discharges into the Lake Michigan basin, a vital freshwater resource that supports diverse aquatic life and provides drinking water for millions. The advanced treatment level ensures removal of nutrients and contaminants, helping to prevent algal blooms and maintain the ecological health of the lake and its shoreline.

The plant discharges into the Lake Michigan watershed, part of the Great Lakes system, which ultimately drains to the Atlantic Ocean via the St. Lawrence River. Lake Michigan supports a rich ecosystem including native fish species and migratory birds. The advanced treatment helps protect the lake from nutrient pollution, which can cause harmful algal blooms and degrade water quality in this ecologically sensitive freshwater sea.