DuPage County DPW Knollwood STP - Burr Ridge, Illinois Wastewater Treatment Plant

The DuPage County DPW Knollwood STP is a municipal wastewater treatment plant located in Burr Ridge, Illinois, serving a population of about 76,324. It operates under the regulatory framework of the U. S. Clean Water Act, which requires National Pollutant Discharge Elimination System (NPDES) permits for all discharges to surface waters. As a facility serving a medium-sized agglomeration, it is expected to provide at least secondary treatment to meet water quality standards. The plant has a designed capacity of 1.00 million gallons per day, indicating a scale appropriate for its service area. Typical plants of this size in Illinois employ activated sludge or similar biological treatment to remove organic matter and nutrients. The facility is operated by DuPage County Department of Public Works, which oversees multiple plants in the region. The treated effluent from the Knollwood STP discharges to local waterways that ultimately drain into the Des Plaines River and then the Illinois River, which flows to the Mississippi River and the Gulf of Mexico. This downstream connection highlights the plant's role in protecting water quality in a major river basin that supports diverse aquatic life and provides drinking water for millions.

The Knollwood STP discharges into the Des Plaines River watershed, a tributary of the Illinois River system. The Des Plaines River flows through northeastern Illinois and joins the Kankakee River to form the Illinois River, which empties into the Mississippi River. This river network supports a variety of fish and wildlife, including migratory birds along the Mississippi Flyway. The plant's operations help maintain water quality in a region with significant urban and agricultural runoff, protecting downstream ecosystems and recreational uses.