Granite City CSO Information

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In March 2023, Illinois American Water (ILAW) acquired the Granite City Regional Wastewater Plant which receives wastewater from Granite City, Metro East Sanitary District, Glen Carbon, and Madison County Special Service Area #1. Since acquiring the system, ILAW has begun putting plans in motion to upgrade the plant, which involves investing over $40 million in the first five years. These investments will support system reliability, public health, and regional service.

Combined Sewer Overflow

A combined sewer system collects rainwater runoff, domestic sewage, and industrial wastewater into one pipe. Under normal conditions, it transports all of the wastewater it collects to a wastewater treatment plant for treatment, then discharges to a body of water. The volume of wastewater can sometimes exceed the capacity of the combined sewer system or treatment plant (e.g., during heavy rainfall events or snowmelt). When this occurs, untreated stormwater and wastewater, discharges directly to nearby streams, rivers, and other bodies of water. This is an environmental and community concern. Through strategic investments, Illinois American Water is working to minimize these occurrences in the Granite City Wastewater System and ensure the plant treats the maximum amount of wastewater possible.

To view information regarding flooding and rainfall events which have impacted the wastewater system please click here.

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