Granite Construction has won a $215 million contract to build a sewer tunnel and divert overflows from the Cuyahoga River in Akron, Ohio, the contractor announced in an Aug. 16 news release.
The Northside Interceptor Tunnel Project is a component of the city’s mandated 2014 consent decree from the EPA to clean up its waterways, according to an update from Akron Mayor Daniel Horrigan.
The NITP will include 6,660 linear feet of precast-concrete-segmental-lined rock tunnel with a finished inside diameter of 16.5 feet, designed to accommodate both dry and wet-weather sewage flow, as well as provide storage, according to Granite.
The structure will help collect combined sewer overflows at four locations, with a storage capacity of more than 10 million gallons to reduce impacts on local waterways.
The project also features an array of control structures, flow drop shafts, connecting sewers and overflow structures to optimize the system's performance. In his update, Horrigan said the tunnel would capture 99% of wet weather flow and treat more than 2.3 billion gallons of water that currently goes back to local waterways untreated.
“Spanning 6,660 feet in length and descending over 100 feet below ground into rock, NITP will be a feat of engineering and is set to become a symbol of innovation and environmental stewardship for the entire region,” said Jim Nickerson, vice president of regional operations for Watsonville, California-based Granite, in the release.
The tunnel is the 25th project the city has taken on under the EPA mandate, which has resulted in a combined price tag of $1 billion. But the city is pushing back against a 26th project, to build a $209 million Enhanced High-Rate Treatment Facility outlined in an amendment to the consent decree, which Horrigan characterized as one of the strictest in the nation.
Project funding for the NITP will come from the Ohio EPA’s Water Pollution Control Loan Fund.
Granite plans to begin the project in September, with completion slated for July 2027.