The Downers Grove Sanitary District will open its Walnut Avenue wastewater treatment plant to the public on Saturday, Oct. 3, offering free tours of the facility that processes wastewater for residents in Downers Grove and Westmont.

The annual Open House runs from 9 a.m. to noon at the district's Wastewater Treatment Center, 5003 Walnut Ave. in Downers Grove. The event is open to residents, students, scout groups and the general public, according to a Village of Westmont civic alert posted Aug. 19.

Westmont uses the Downers Grove Sanitary District as one of its two wastewater treatment centers, making the open house relevant to residents on both sides of the municipal boundary.

Last year's open house, held Oct. 4, 2025, featured guided tours, a touch-a-truck display, interactive exhibits and refreshments. The district has not yet published a full activity lineup for the 2026 event on its open house page.

The facility has been a focus of planning discussions this year. In May, the district's Board of Trustees held a special meeting that doubled as a walking tour of the treatment center, focused on future capital improvement needs.

The district describes the event as a chance for the public to see how a local wastewater treatment plant operates from start to finish. No registration is required.

The district can be reached at (630) 969-0664 for questions about the event.