Minneapolis and St Paul are building a light rail line connecting the ‘Twin Cities’. Detroit anticipates starting construction on a light rail line this year, and Cincinnati a new streetcar line. None of these projects will include major underground construction. Compared to the nation’s coastal cities, the Midwest has more land to build roads, and does not have the existing public transport to require tunnels.
But that is not to say tunneling is in short demand. The market is strong due to water and wastewater projects in the region, especially in Ohio and Indianapolis, with several multi-million dollar contracts tendered in 2010 and upcoming in 2011.
“In the Midwest the most visible drivers are definitely around combined-sewer and sanitary-sewer overflow regulations,” says David Egger, director of Black & Veatch’s heavy civil group. “Aging infrastructure is a current national crisis, which is a driver that we are waking up to, but there are also drivers related to water scarcity and water supply, particularly in the southern part of the Midwest, where water needs to be moved long distances. Tunneling solutions are being increasingly considered there.”
According to the EPA, combined sewer systems are mostly concentrated in the Northeast and Great Lakes regions, though stretching as far west as Iowa and Missouri. The EPA estimates that the capital costs of future CSO control over the next 20 years will exceed USD 50bn.
Cities in Ohio have consent decrees with the state to meet the requirements of the EPA’s Clean Water Act. These cities have developed billion dollar long-term control plans, spanning 20 to 40 years, to alleviate combined-sewer systems, often with larger diameter storage and conveyance tunnels.
Groundbreaking started in Columbus, Ohio, early this year on the first of three deep tunnels for the city’s USD 5.4bn Wet Weather Water Management Plan. A Kenny-Obayashi joint venture is building the 7km OARS tunnel measuring 7m in diameter. Two more tunnels on the east and west side of town—the 21km Alum Creek Relief Tunnel and the 18km Olentangy Relief Tunnel—will be constructed to relieve sanitary sewer overflows in 2014 and 2018, respectively.
The Northeast Ohio Regional Sewer District has its USD 3bn Project Clean Lake, a 25-year program seeing construction of seven tunnels, ranging from 2 to 5mi (3 to 8km) in length. A McNally-Kiewit joint venture is scheduled to start construction in March on the Euclid Creek Storage Tunnel in Cleveland, Ohio, having secured a USD 198.6M in December 2010. The 17,750ft (5.5km) tunnel with a 24ft diameter (7m) will be completed in four years’ time. Tunnel depth will vary between 190 to 220ft (58- 67m) through Chagrin Shale bedrock and the alignment will include a 3,000ft (914m) stretch below Lake Erie.
The Euclid tunnel is phase one of a storage system for the Euclid Creek Area. Phase two, the estimated USD 128.4M Dugway Storage Tunnel, concerns another 24ft (7.3m) diameter tunnel, 16,000ft long (5km) and 200ft (61m) below ground. Design contracts are expected to tender in 2013, and construction contracts in 2015.
In the southwestern part of the state, engineers from Black & Veatch are currently conducting geotechnical investigations for a proposed 1.2mi (1.9km) long tunnel with a 30ft (9.1m) diameter for the Metropolitan Sewer District of Greater Cincinnati. The USD 244Mproject will also include a pump station and treatment facility, and is part of the larger Project Groundwork, valued at approximately USD 3.3bn, to reduce combined sewer overflows in Cincinnati. Once the alignment is determined and approved, detailed design is expected to begin this year. Construction should be completed in 2018.
Mega cities like Chicago and St. Louis have long looked to tunneling solutions, but the tunneling industry has more recently been measurably penetrating additional cities such as Indianapolis and Omaha, says Egger. “That’s being driven by the technology and more confidence in contracting approaches. Tunneling is a much more accepted and widely understood construction technology now than, say, 15 years ago.”
He’s not only referring to technological advances in tunneling that have allowed projects to finish faster and make less disruptions—the Internet has played a role too. When working with clients on project development and speaking with the public about open-cut solutions versus deep underground solutions, people are more informed and tend to more quickly embrace tunneling compared to open-cut approaches. “People will go to a public meeting, hear a little bit about tunneling and then they are out there doing their own research. They tend to see the benefits very quickly,” explains Egger.
Another trend he points out is that building a tunnel is increasingly understood as an option that can sometimes avoid the need to pump water and be very energy efficient. Whether looking at that from a green or economic perspective, it’s appealing.
Construction broke ground in Columbus in early 2011
