Glendale Heights STW - Wastewater Treatment Plant in Glendale Heights, Illinois

Glendale Heights STW is a municipal wastewater treatment plant located in Glendale Heights, DuPage County, Illinois. It serves a population of about 39,164, placing it in the medium-agglomeration category for U.S. facilities. The plant is situated in the Chicago metropolitan area, a region with extensive water infrastructure managed by local and state agencies. As a U.S. facility, the plant operates under the National Pollutant Discharge Elimination System (NPDES) permit program, which sets effluent limits based on the Clean Water Act. Plants of this scale typically employ secondary treatment as a minimum, with potential nutrient removal requirements due to the sensitivity of downstream waters. The designed capacity is 1.00 million gallons per day, indicating a facility sized for the community's needs. The plant's treated effluent discharges into the DuPage River system, which flows into the Des Plaines River and ultimately into the Illinois River and Mississippi River. This watershed supports diverse aquatic life and provides drinking water for downstream communities. The plant plays a key role in protecting water quality in this densely populated region, helping to reduce nutrient loads and pollutants that could impact the Gulf of Mexico hypoxic zone.

The plant discharges into the DuPage River, a tributary of the Des Plaines River, which flows into the Illinois River and then the Mississippi River. This watershed drains a large agricultural and urban area, contributing to nutrient loading concerns in the Gulf of Mexico. The plant's location in a suburban setting means its effluent quality is critical for maintaining local stream health and supporting recreational uses.