CHA Consulting, Inc. (CHA) has received an Honor Award at the ACEC Ohio 2026 Engineering Excellence Awards for the Moler Street Overflow Interceptor Sewer in Columbus. The project was recognized for its innovative, sustainable approach to wastewater management and its measurable impact on environmental protection and community resilience.
For decades, heavy rainfall overwhelmed Columbus’s combined sewer system, causing untreated overflows into the Scioto River and flooding nearby neighborhoods. In partnership with the City of Columbus, CHA designed a long-term solution to address one of the city’s most persistent overflow points. At the core of the project is a 96-inch-diameter interceptor sewer installed deep beneath Moler Street. The system redirects excess flow into the city’s underground OARS tunnel system, where it can be safely stored and treated.
To minimize disruption in a dense urban corridor, CHA used trenchless construction methods to install the tunnel entirely underground, avoiding impacts to homes, businesses, and two active rail lines. Engineers navigated complex subsurface conditions, drilling more than 60 feet between two aquifers while maintaining their integrity. Contaminated soils encountered during construction were treated and reused on-site, reducing waste and environmental impact. The project has eliminated sewer overflows into the Scioto River, improved water quality, reduced basement flooding, and helped the city meet requirements set by the Ohio Environmental Protection Agency.
The Moler Street Overflow Interceptor Sewer demonstrates how forward-thinking engineering can deliver cleaner waterways, healthier communities, and long-term infrastructure resilience. CHA joined others to celebrate Ohio’s engineering achievements at a luncheon held by ACEC Ohio on February 19, 2026.
ACEC Ohio represents approximately 167 independent engineering firms that offer a wide range of construction design and consulting services. ACEC Ohio member companies employ more than 8,000 people and produce annual net revenues of $600 million annually. Learn more at ACEC Ohio's website.