Winner of 2015 ACEC Award
2015 Snapshot:
What began as a regulatory challenge for the City of Belleville became an award-winning example of innovation, sustainability, and practical engineering. Faced with increasing pressure to reduce Combined Sewer Overflows (CSOs) and comply with Illinois and U.S. EPA regulations, the City partnered with TWM to develop a long-term solution that would improve water quality while remaining financially responsible for residents.
Rather than relying solely on costly new infrastructure, TWM identified an opportunity to repurpose existing sludge lagoons into CSO management basins—transforming underutilized infrastructure into a key component of the City’s Long-Term Control Plan. This innovative approach significantly reduced construction costs and minimized impacts to sewer rates while still delivering substantial improvements in overflow control and effluent quality.
The expansion and modifications also incorporated green technologies designed to improve energy efficiency and reduce environmental impacts, demonstrating that infrastructure upgrades can support both operational performance and long-term sustainability goals.
The entire project also included a new 200 MGD pump station and a counter current aeration system for both energy savings and nutrient removal, UV disinfection, and conversion of existing anaerobic digesters to autothermal thermophyllic aerobic digestion. As part of the digester conversion, TWM provided a 3D scan of the existing congested piping building so that precise locations for all interior piping were known. The surveying scope also included topographic and boundary surveys in addition to as-built drawings of the existing facilities (concrete tanks, slabs, CMU buildings, foundations, platforms and walkways, pipe bridge) that were modified or impacted by design.
The final design increased treatment capacity by more than 50%, from a daily average flow of 8.0 to 12.4 million gallons per day to support growth and development in Belleville.
The success of the project earned national recognition, receiving both the 2015 ACEC Honor Award and National Recognition Award in the Waste & Stormwater category. More importantly, the project positioned Belleville to better protect local waterways and support future community growth through resilient, forward-thinking infrastructure.
