McHenry Central STP | Wastewater Treatment Plant in McHenry, Illinois, USA

McHenry Central STP is a municipal wastewater treatment facility located in McHenry, Illinois, serving a population of about 11,928 residents. The plant is situated in the Fox River watershed, an inland area within the Great Lakes Basin, and plays a key role in managing local wastewater for this community. As a US-based plant serving a medium-sized agglomeration, McHenry Central STP operates under the regulatory framework of the Clean Water Act, administered through the National Pollutant Discharge Elimination System (NPDES) permit program. The Illinois Environmental Protection Agency issues permits that set effluent limits to protect water quality. Plants of this scale typically employ secondary treatment as a minimum standard. The treated effluent from McHenry Central STP discharges into the Fox River, which flows southward to the Illinois River, then to the Mississippi River, and ultimately to the Gulf of Mexico. The plant's operations help protect the Fox River's aquatic life and downstream water quality, supporting recreational uses and ecosystem health in the region.

McHenry Central STP discharges into the Fox River, a tributary of the Illinois River, which flows into the Mississippi River and eventually reaches the Gulf of Mexico. The Fox River supports diverse aquatic species and is used for recreation, making nutrient and pollutant control important for maintaining water quality and preventing downstream eutrophication.