After decades of planning, preliminary work on Akron’s giant underground sewage tunnel is visible at three spots at the edge of downtown.
The initial work on the Ohio Canal Interceptor Tunnel can be seen north of the Mustill Store off West North Street along the Little Cuyahoga River, between Glendale Cemetery and the John F. Seiberling Federal Building and U.S. Courthouse and off West Exchange Street near Canal Park, the RubberDucks baseball stadium.
Off West Exchange Street, a giant concrete ring marks the outline of a not-yet-drilled vertical shaft at the southern terminus of the tunnel.
Vertical shafts are also taking shape near the cemetery, the federal building and Mustill Store.
The project requires drop shafts and diversion structures that are needed to lower nine overflowing sewers into the new and deeper tunnel.
“Drilling the tunnel is only one part of what needs to be done,” Akron engineer Michelle DiFiore said. “Building the tunnel is actually the easy part of the job.”
The $184.1 million tunnel is the key element in the city of Akron’s overall plan to curtail sewer overflows into the Cuyahoga and Little Cuyahoga rivers and the Ohio & Erie Canal. The entire initiative has an estimated cost of $1.1 billion, although Akron hopes to win federal approval to revise its plan to add green or environmentally friendly projects and reduce the bill to $800 million.
Boring the sewer tunnel from near the Mustill Store will begin next March — eight months earlier than planned.
The earlier start to the Ohio Canal Interceptor Tunnel was requested by the contractor hired by the city to oversee the tunnel project, city officials said. The low bidder was a joint venture of Illinois-based Kenny Construction Co. and Tokyo-based Obayashi Corp.
Under a federal consent decree, the tunnel’s completion date remains Dec. 31, 2018.
The tunnel is part of a federal order that affects 300,000 people in Akron and its suburbs who are paying higher sewer rates.
The tunnel, 27 feet in diameter, will stretch 6,240 feet from off West Exchange Street to near the Mustill Store at depths of 70 to 160 feet.
It will be capable of storing up to 25 million gallons of sewage and storm water from Akron’s overflowing sewers. The runoff will be stored and then directed to the city’s sewage plant for treatment.
Machine assembled
The Robbins Co. in Solon is beginning to assemble the pieces of the giant machine that will be used to create the tunnel. The company has been hired to build the 400-foot-long machine with a rotating cutter that is 30 feet in diameter and weighs 200 tons.
The machine will be assembled in Solon, tested, taken apart, packed, transported to Akron and reassembled at the staging area off Cuyahoga Street north of downtown Akron.
Work on shipping the components to Akron will begin this fall. The machine will be put together off Cuyahoga Street over the winter.
The boring machine has three jobs: excavate rock and soil, remove it from the tunnel and build a concrete tunnel liner. The key parts of the machine are a large metal cylinder with a rotating cutting head at the front and a conveyor belt at the back to remove the stone and dirt. Inside is a system to install a permanent concrete tunnel liner.
The area north of the Mustill Store is ground zero for preliminary tunnel-construction activities.
“There is a lot of activity in a fairly small space,” said Chris Ludle, Akron’s deputy service director. “It’s exciting.”
Up to 40 workers plus office staff are at work where the Ohio & Erie Canal empties into the Little Cuyahoga River. It is the northern terminus of the tunnel and the place where the tunnel machine will begin its boring.
The area is fenced off and connected to a staging area off Cuyahoga Street via two new construction bridges over the Little Cuyahoga River.
Metal sheet piles to hold the soil in place are being installed with a hydraulic pile-driving machine. It results in less noise than traditional pile drivers.
Tiebacks or horizontal rods or anchors are being added to reinforce the retaining walls for added stability.
The excavating is needed to lower the site to the proper elevation for the boring machine.
The soil at the site is also being treated with sprayed grout to harden it and condition it for the boring machine, officials said.
Monitoring equipment has been installed to check ground movement, vibrations and noises through the construction.
Soil from the tunnel boring will be hauled to a Kenmore Construction Co. yard just north of the site off Cuyahoga Street. Kenmore Construction is a subcontractor on the tunnel project.
Using that site will save Akron significant dollars, Ludle said.
Ohio Edison Co. has installed a temporary electrical substation to power the tunnel borer.
CSI Hanson JV of Macedonia is under contract to produce the needed pre-cast concrete tunnel rings that will line the inside of the tunnel.
Akron has created a new Towpath Trail route along Hickory Street between West North Street and Memorial Parkway because of the sewer work near the Mustill Store. It will be used until 2018.
Trail to be rerouted
The city will soon be rerouting Towpath Trail visitors between the baseball stadium and the Spaghetti Warehouse restaurant at the southern edge of downtown.
A special bicycle lane will be designated along South Main Street for bicyclists and walkers can use the sidewalk, DiFiore said. Those routes will be in place in May, although signs are already posted, she said.
Along with the giant tunnel dig, Akron will have another 15 sewer projects under construction throughout Akron this year as the city works to comply with federal orders to curtail the sewer overflows.
About one-third of Akron’s sewer system relies on combined sewers, which are a single pipe into which both human waste and storm water flow and then are discharged into local waterways to prevent backups into buildings. Akron had 38 overflow spot, which produced overflows of 1.2 billion gallons a year at its peak.
Bob Downing can be reached at 330-996-3745 or bdowning@thebeaconjournal.com.