Oakley Station CSO Tunnel DB

The Oakley Station Sewer Separation Project provides stormwater collection and transport for a 75-acre brownfield redevelopment. The centerpiece of this project was a 2600', 72" diameter tunnel installed using double-pass tunnelling methods. The tunnel was constructed under and through a flourishing development in Cincinnati, requiring diligent coordination with the surrounding businesses.

The rapid progress of the Oakley Station development, combined with the City's Conset Decree Agreement with the EPA, dictated that the Separation Project be fully expedited. The aggressive schedule, combined with the unknown nature of the subsurface conditions in the area, led Cincinnati MSD to select the Design-Build delivery method for the project. The collaborative environment allowed the team to overcome significant challenges, including the discovery of undocumented subsurface structures which required rerouting the tunnel trunkline. In spite of these challenges, the Ulliman Schutte Design-Build team was able to deliver the project 13 months ahead of the original schedule and over 20% below the project budget.