Indianapolis water owner Citizens Energy Group plans to award soon an estimated $500-million contract to S-K JV, a joint venture between J.F. Shea and Kiewit, to complete the remaining 18 miles of deep tunnel work in Indianapolis to mitigate combined sewer overflows by 2025.

“Right now, we have a notice of award contingent on final negotiations,” says Stuart Lipofsky, project manager for S-K. The owner, CEG, plans to issue the contract by June 1, adds John Trypus, director of underground engineering and construction at the water authority.

The contractor has completed 50% of the concrete lining of the first major portion of the $1.9-billion program, now called the Dig Indy Tunnel System. S-K began work on the initial 9-mile job, the Deep Rock Tunnel Connecter, in 2011.

The company has mined out roughly 50,000 ft using a refurbished 20-ft-dia tunnel-boring machine; it is now daily pouring concrete into the tunnel, lined at 18-ft-dia and located more than 200 ft below the city.

Next steps will include mining the 5.8-mile White River and 1.8-mile Lower Pogues Run tunnels, some of which will take the TBM directly below the Lucus Oil Stadium in downtown Indianapolis. Under federal requirements, this work needs to be completed by 2021, but the owner says it is scheduled to wrap up a year in advance. Future projects include Fall Creek, at 3.8 mi, and Pleasant Run, at 7.3 mi, which are slated to finish by 2025.

By letting the remaining tunnels into one contract, rather than several, the owner claims to have saved $70 million in costs for a total of $400 million in savings through additional value engineering.

“One of the added benefits and part of the negotiation was using one TBM as opposed to two,” Trypus notes.

The future work offers S-K JV with good work ahead, Lipofsky adds. "We are very excited about it," he tells ENR. "To have 100,000 ft of tunnel and three big jobs ahead of you for eight years isn't something that's very common in our industry."

Dig Indy is believed to be the largest public works project in Indiana state history.