Wisconsin Rapids STP | Municipal Wastewater Treatment Plant in Wisconsin Rapids, Wisconsin

The Wisconsin Rapids Sewage Treatment Plant (STP) is a municipal wastewater facility located at 2545 1st Street South in Wisconsin Rapids, Wood County, Wisconsin. It serves an estimated population of 25,553, classifying it as a medium-sized agglomeration under typical US regulatory categories. As a US-based facility, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, administered by the Wisconsin Department of Natural Resources. The Clean Water Act requires secondary treatment as a minimum for municipal plants of this scale, ensuring adequate removal of organic matter and suspended solids before discharge. The plant's treated effluent is discharged into the Wisconsin River, a major tributary of the Mississippi River system. The Wisconsin River flows southward through central Wisconsin, eventually joining the Mississippi River near Prairie du Chien. This waterway supports diverse aquatic life and is an important recreational and ecological corridor in the region.

The Wisconsin River, which receives the plant's discharge, flows approximately 430 miles through central Wisconsin before joining the Mississippi River. This reach of the river supports a variety of fish species, including walleye and smallmouth bass, and provides habitat for migratory waterfowl. The river's watershed encompasses agricultural and forested lands, and the plant's nutrient removal performance is important for downstream water quality in the Mississippi River basin.