The Downers Grove Sanitary District is responsible for providing sanitary sewer service for the Village of Downers Grove, the portion of the Village of Westmont west of Cass Avenue and portions of Woodridge, Lisle, Lombard, Oak Brook, and Darien, Ill. It is a separate unit of Illinois local government. Organized in 1921, The Downers Grove Sanitary District provides sewer service to around 20,000 customers, including wastewater generated by more than 60,000 people and a number of commercial, industrial and institutional customers. The community operates and maintains a sewer system with over 245 miles of sewer main.