Spring Grove Wastewater System - Lotus Woods, Illinois Secondary Treatment Plant

Spring Grove Wastewater System is a municipal treatment facility located in Lotus Woods, Lake County, Illinois. It serves a population of approximately 5,782 residents, operating as part of the region's wastewater infrastructure. The plant is situated inland, about 50 km from Lake Michigan, and its treated effluent flows into local streams that drain toward the Fox River and ultimately the Great Lakes basin. The facility provides secondary treatment, which is the standard level required by the U.S. Clean Water Act for municipal wastewater plants. Under the National Pollutant Discharge Elimination System (NPDES), plants of this scale must meet effluent limits for biochemical oxygen demand and total suspended solids. The plant's designed capacity is 283.91 million gallons per day, with a current discharge volume of 246.05 million gallons per day, indicating operational headroom. The treated wastewater is discharged into nearby water bodies that are part of the Fox River watershed. This river flows into the Illinois River, which joins the Mississippi River and eventually reaches the Gulf of Mexico. The plant's operations are regulated to protect downstream aquatic habitats, including fish spawning areas and wetlands that support diverse wildlife.

The plant discharges into local streams that feed the Fox River, a major tributary of the Illinois River. The Fox River watershed supports diverse aquatic life, including game fish and migratory birds. Downstream, the Illinois River connects to the Mississippi River, which drains into the Gulf of Mexico. The plant's secondary treatment helps reduce nutrient loading, which is critical for preventing algal blooms in the Great Lakes and Gulf hypoxia zone.