Chicago – October 19, 2026 -- The HNTB-designed South Conveyance Storm Sewer Project at O'Hare International Airport has won the American Society of Civil Engineers Illinois Section's 2026 Outstanding Civil Engineering Achievement Award in the more than $100 million category, after crews tunneled beneath active runways and taxiways without interrupting airport operations.
HNTB engineered tunnel under live airfield for Chicago Department of Aviation
The project provides stormwater infrastructure to support O'Hare's continued modernization and future development. HNTB served as engineer of record and worked with the Chicago Department of Aviation (CDA) and project partners to develop and implement the tunnel solution beneath active airfield infrastructure.
17-foot boring machine advanced beneath two active runways
Crews built the tunnel through challenging subsurface conditions using a 17-foot-diameter earth pressure balance tunnel boring machine. The machine passed beneath two active runways and several taxiways while flights continued above. Real-time instrumentation and monitoring helped protect critical airfield infrastructure throughout excavation.
Mark Stephani, HNTB principal engineer of geotechnical and tunneling, said the team's solution managed complex ground conditions and reduced risk at critical runway crossings.
Construction manager at risk method brought contractor in early
The project was delivered using the construction manager at risk method, which allowed early contractor involvement and collaboration. The approach helped the team evaluate construction alternatives, improve constructability and advance the tunnel boring machine solution.
CDA ties sewer to ORDNext program
CDA Managing Deputy Commissioner Zach Baughman, who is the ORDNext program chief, said completing the work without interrupting operations strengthens the airport's ability to provide a safe, reliable experience for passengers and airlines.
The project team received the award at the ASCE Illinois Section's Annual Awards Banquet in Chicago.