HNTB-designed O'Hare South Conveyance Storm Sewer Project earns Outstanding Civil Engineering Achievement Award

Innovative tunnel design supports O'Hare modernization while maintaining active airfield
operations

CHICAGO, Oct. 19, 2026 /PRNewswire/ -- The HNTB-designed South Conveyance Storm Sewer Project at O'Hare International Airport has received the American Society of Civil Engineers Illinois Section's 2026 Outstanding Civil Engineering Achievement Award in the more than $100 million category. The award recognizes the project's innovative tunnel solution constructed beneath active runways and taxiways while maintaining uninterrupted airport operations.

Delivered for the Chicago Department of Aviation, the project provides critical stormwater infrastructure to support O'Hare's continued modernization and future development. HNTB served as engineer of record for the project, working closely with the department and project partners to develop and implement the tunnel solution beneath active airfield infrastructure.

"The South Conveyance Storm Sewer Project is a critical investment in O'Hare's future," said CDA Managing Deputy Commissioner Zach Baughman, the ORDNext program chief. "Completed without interrupting airport operations, it strengthens our ability to provide the safe, reliable experience passengers and airlines depend on while advancing our long-term vision for O'Hare."

The tunnel was constructed through challenging subsurface conditions using a 17-foot-diameter earth pressure balance tunnel boring machine. During excavation, the machine advanced beneath two active runways and several taxiways while airport operations continued above. Real-time instrumentation and monitoring helped protect critical airfield infrastructure throughout excavation.

"Constructing a tunnel of this scale beneath an active airfield required careful planning, close coordination and precise control throughout excavation," said Mark Stephani, HNTB principal engineer of geotechnical and tunneling. "The team developed an innovative solution that managed complex ground conditions, reduced risk at critical runway crossings and delivered the stormwater capacity needed to support O'Hare's future."

The project was delivered using the construction manager at risk method, allowing early contractor involvement and collaboration. The approach helped the team evaluate construction alternatives, improve constructability and successfully advance the tunnel boring machine solution.

The project team received the award during the ASCE Illinois Section's Annual Awards Banquet in Chicago.

About HNTB

For more than a century, HNTB Corporation has been at the forefront of designing and advancing transportation infrastructure that enhances mobility and improves local communities. With client relationships spanning decades, we understand infrastructure life cycles and have perspective and experience to solve the most complex technical, financial and operational challenges with vision and imagination. As employee owners committed to excellence, we prioritize client success while delivering a full spectrum of infrastructure-related services. Discover HNTB's Spark at www.hntb.com, or follow us on LinkedIn, X, Facebook or Instagram.

SOURCE HNTB