A Granite-Super Joint Venture has secured a US$324.8bn tunnelling contract for Ohio’s Big Creek Tunnel.
The project is the last of seven large-diameter combined sewer overflow (CSO) storage tunnels for Northeast Ohio Regional Sewer District’s Project Clean Lake, a US$3bn, 24-year programme that began in 2011.
The combined projects will stop 4.5 billion gallons of CSO being released into Lake Erie and other local waterways in the Greater Cleveland area.
Granite-Super’s scope of work includes construction of a 6.8km, 6m-diameter tunnel and 950m feet of ancillary tunnels, including adits, an overflow tunnel, a connecting tunnel, and a dewatering tunnel.
The joint venture will also construct multiple shafts, diversion structures, gate and screening structures, gate control vaults, consolidation sewers, and an overflow box culvert, along with associated sitework, restoration, and utilities.
The tunnel system will capture and store a combination of sanitary sewage and stormwater from 11 CSO outfalls. When complete, it will eliminate 550 million gallons of combined sewer releases annually.
“The scale and complexity of this project align directly with Granite’s strengths in large-diameter tunnelling and shaft construction,” said Granite Tunnel Division vice-president Jim Nickerson. “This is a major wastewater infrastructure project, and it will strengthen system performance and protect local waterways across Northeast Ohio.”
Construction is scheduled to begin before the end of the year and is expected to be completed in winter 2030.
