CAROLINE SD 1 STP - Advanced Wastewater Treatment in Town of Grant, Wisconsin

CAROLINE SD 1 STP is a municipal wastewater treatment facility located on Romberg Road in the Town of Grant, Shawano County, Wisconsin. Serving a small population of 315 residents, the plant provides advanced treatment to protect local water quality. The plant operates with a designed capacity of 68.14 million gallons per year and currently treats approximately 64.35 million gallons annually. As an advanced treatment facility, it goes beyond secondary treatment standards to remove nutrients and other pollutants, meeting stringent requirements under the U.S. Clean Water Act. Treated effluent from the plant is discharged into a local waterway that drains into the Wolf River basin, ultimately reaching Lake Michigan via Green Bay. The advanced treatment helps safeguard downstream aquatic ecosystems and supports recreational and ecological uses of the receiving waters.

The plant discharges into a tributary of the Wolf River, which flows into Lake Michigan via Green Bay. This watershed supports diverse aquatic life, including coldwater fish species, and is an important migratory corridor for birds. Advanced treatment at the plant reduces nutrient loading, helping to prevent algal blooms and maintain water quality in the downstream Great Lakes ecosystem.