Construction of the Northside Interceptor Tunnel (NSIT) began in September 2023, with the 1) Project Mobilization, 2) Site Preparation, and 3) Construction of a Temporary Sewer.
1) Mobilization: Construction began with a mobilization effort that included the installation of construction trailers and the construction of several utilities. Construction Trailers: Construction trailers were successfully moved into the site, providing on-site facilities for the contractor and construction management teams.
Utilities: Due to the remote location of the main construction site, new utilities were required.
Waterlines were installed to ensure a reliable water supply for construction activities.
Powerlines were installed to provide the necessary electrical infrastructure for construction.
A power transformer was refurbished from the Ohio Canal Interceptor Tunnel project and relocated to the NSIT site.
Internet fiber was installed to facilitate communication and data transfer across the site.
2) Site Preparation: Throughout the fall and winter months, the contractor focused on site preparation activities. This included surveying, excavation, grading, leveling, clearing land, drainage, and earthmoving. This work also included constructing temporary access roads that lead to areas where various structures will be built. The contractor will use the access roads throughout the project to transport construction materials and equipment.
3) Construction of Temporary Sewer: The contractor started building a temporary sewer that includes two 48” pipes and a large headwall. The sewer will be active throughout construction, but eventually abandoned when the sewer flow is diverted to the tunnel at the end of the project.
The Lower Northside Interceptor (NSI) Lining Project was completed in late summer 2023. The Project rehabilitated the existing Northside Interceptor, which runs along Peck Road and was originally constructed with bricks in 1930.
The Riverside Sewer Separation Project is in full swing. The focus of the project currently is along Riverside Drive near Linden Avenue, where new storm sewers are being constructed.
The Lower Northside Interceptor Lining Project includes the rehabilitation of a 48" brick sewer located along Peck Road entirely within the Cascade Valley Metro Park - Chuckery Area.
The Riverside Sewer Separation Project involves construction of new storm sewers in the North Hill neighborhood located along Riverside Drive and along streets that are located between Big Falls and Drexel Avenue.
The Northside Interceptor Tunnel project consists of constructing a 16.5-foot internal diameter tunnel, beginning at the Cascade Valley Metro Park - Chuckery Area, generally following Riverside Drive, and terminating near the Front Street Bridge.
Read the latest news about NSIT:
Akron Beacon Journal Article:
Court gives OK to downsize sewer tunnel
System overhaul could save ratepayers $50M
A federal district court has formally approved Akron’s plan to reduce the size of its Northside Interceptor Tunnel meant to prevent sewage from overflowing into the Cuyahoga River, an amendment that will ultimately save sewer ratepayers millions of dollars.
Though approval of the reduced size was a formality that was previously OK’d by state and federal environmental officials, it marks a final win for Mayor Dan Horrigan in his last days in office.
However, the city’s request to eliminate the final project in its $1 billion sewer overhaul — an additional proposed treatment plant in the middle of town — remains pending.
Horrigan announced Thursday that the court approved the Northside project amendment, allowing the city to reduce the tunnel’s diameter size from 24 feet to 16.5. The U.S. EPA, which mandated the project, had initially proposed the larger size for the tunnel, which will store combined sewage and stormwater for treatment in the city’s wastewater treatment plant.
Built in the last century, much of the city’s sewer system had been combined with a stormwater management network, with the combined volume being channeled into the wastewater plant.
However, during severe rainstorms, the volume exceeds the plant’s capacity, and the system can overflow. That combined stormwater and sewage overflows into the Cuyahoga River at various locations referred to as “racks.”
That pollution led the U.S. EPA to mandate major upgrades to the city’s wastewater system. Requirements included building interceptor tunnels to retain the combined sewage and stormwater for gradual release into the sewage treatment plant, preventing overflows into the river.
“Based on the city’s improved and updated modeling, the ‘right size’ Northside Interceptor Tunnel will provide for control of combined sewer overflows beyond the typical year rainfall event and the elimination of combined sewer overflows from the Rack 34 area,” the city said in a release.
The Rack 34 area includes the neighborhood between Big Falls Avenue and the Cuyahoga River in North Hill, where the city is building new storm sewers. The existing combined sewers will be repurposed as separate sanitary sewers to eliminate combined overflows from this area.
This decision will save Akron’s ratepayers an estimated $50 million, bringing the total savings from initial EPA mandates to $215 million during Horrigan’s tenure, the release said.
The court found that the amendment was fair, adequate and reasonable, as well as consistent with the public interest. The amendment was supported by the U.S. and Ohio EPA, the release continued.
“Akron continues to meet and exceed the requirements of the Consent Decree while continuously looking for ways to reduce costs for its ratepayers and to provide environmental benefit to its citizens and the region,” Horrigan said. “I’m proud of the outstanding work this team has done to clean up our waterways while also pursuing any and all cost-savings for our ratepayers.”
Akron Director of Public Service Chris Ludle said the city received informal approval from the state and federal EPAs for the smaller tunnel in May 2022. A request to formalize that approval was filed in February by the U.S. EPA, and a $215 million bid for the project was approved in July.
He said the tunnel boring machine, which must be custom-built, has been put on order.
“We had to bid this project by a certain date,” he said. “The EPAs did agree with us, so we went forward and we said, ‘You agree with us − both EPAs − [and] we’re going to send this to federal court [to formalize the agreement], but to meet our deadline to get this done by the end of 2026, we’ve got to go − they’re building this machine in Germany right now.”
A 2014 federal court consent decree between the city and EPA mandates the city clean up its sewer overflow by Dec. 31, 2026.
The city expects the sewer separation for Rack 34 will be in service prior to Dec. 31, 2024.
The city said that with the completion of these projects, Akron will capture 99% of the wet weather flows entering the combined sewer system and reduce the original annual number of combined sewage overflow events by 99.7%.
The city said this is the third successful amendment to the 2014 consent decree, all of which have provided greater environmental benefits earlier than required by the consent decree. These three amendments have saved Akron ratepayers an estimated $215 million.
Ludle said the city plans to seek a fourth and final amendment to eliminate an Enhanced High Rate Treatment plant (EHRT). If approved, it could provide an additional $150-$200 million in savings, according to the city.
The EPA proposes the plant be built to handle overflows that might occur from the Ohio Canal Interceptor Tunnel, which was completed in 2020.
The EHRT would treat the last 100 million or so gallons that might overflow in a typical year, though nothing has overflowed for two years.
Ludle said the city’s request for the final amendment has not yet been filed with the court.
“We’re still talking to them about a solution for that treatment facility,” he said.
Eric Marotta can be reached at email@example.com.