The work of “Elaine,” the tunnel-boring machine tasked with carving out the 6,660-foot-long Northside Interceptor Tunnel (NSIT) beneath the northern edge of Akron’s Cascade Valley and North Hill areas, is helping the City of Akron near the finish line for federally mandated projects aimed at improving the area’s water quality.
One of the final and most significant pieces of the puzzle, the NSIT, is designed to reduce combined sewer overflows, a legacy of Akron’s original sewer system.
Since Akron is an old city, like many cities in Ohio and nationwide, it was built around a combined sewer system, said project manager Heather Ullinger, who is also the senior engineer for the Akron Engineering Bureau.
In Akron, those overflows meant raw sewage, along with potential industrial waste, toxic materials and debris, flowed on a regular basis into the Cuyahoga River during high-volume rain events, killing off fish populations and other wildlife.
In a combined sewer system, stormwater and sanitary waste are collected in the same pipe as they travel to a water treatment facility. While this system works under typical conditions, it can become problematic during heavy rainfall, when the volume of water exceeds the system’s capacity and leads to raw sewage spilling into the region’s waterways.
Elaine, the tunnel-boring machine
No conversation about the NSIT is complete without mentioning “Elaine,” named after longtime Ohio environmental advocate Elaine Marsh, one of the founding members of Friends of the Crooked River. The nonprofit organization focuses on giving a voice to the Cuyahoga River and has been advocating for river restoration and conservation projects since 1990, including the removal of the Gorge Dam.
“It was like almost without hesitation that that name came forward as the name for the tunnel-boring machine. Elaine has worked tirelessly as the cheerleader of the Cuyahoga River and restoring it. She’s just an amazing force to be reckoned with,” Ullinger said.
Marsh had the chance to meet the 460-foot-long, 619-ton machine earlier this year and said the experience felt like she was floating.
“When you’re around for a long time and you have a big mouth, people tend to know you and recognize you in a number of humbling and wonderful ways.” Marsh said. “But to have a tunnel boring machine named after you is like the pinnacle.”
Where is the tunnel being dug?
Elaine is tunneling from the Chuckery Area of Cascade Valley Metro Park, winding its way along Riverside Drive to Front Street. The machine is capable of advancing about 50 feet per day, with its breakthrough projected about five months after it began working at the end of April.
To stay up to date with Elaine’s progress, visit the Akron Waterways Renewed! website.
The tunnel itself is constructed using precast concrete segments that are pieced together like a giant jigsaw puzzle. Each segment is carefully labeled, ensuring the right pattern is followed to maintain structural integrity. Workers operate the tunnel-boring machine from 7 a.m. to 2 p.m. Monday through Friday, with Saturdays reserved for maintenance.
The tunnel must be online and receiving flow by Dec. 31, 2026. Any clean-up tasks, like restoring pavement or replanting trees, must be completed by July 1, 2027.
How will the new system work?
The NSIT is designed to capture and store excess flow during rain events, preventing combined sewer overflows from contaminating Akron’s waterways. It will function as a massive underground storage reservoir, holding up to 10.5 million gallons of combined sewage.
The tunnel is built to receive “dry weather flow,” which refers to the everyday waste that enters the sewer system, like toilet flushes, showers and sink drains. Under normal, non-rainy conditions, the water will flow into the tunnel, where it will be stored until it can be treated at a water reclamation facility.
During a rain event, stormwater will mix with the sanitary sewer, and the tunnel’s valve system will allow for temporary storage of the excess water. The tunnel will act as a storage basin for four combined sewer overflow locations.
“If we did not have a relief point, we would be backing up sewage into basements and blowing off manhole covers,” Ullinger said.
Is the water quality improving in Northeast Ohio?
The U.S. Environmental Protection Agency mandated changes to the city’s wastewater system in 2009 when it issued a federal consent decree. Akron Waterways Renewed! is the city’s initiative for completing the 26 water and sewer infrastructure projects required by the EPA.
So far, Akron has completed 24 of those projects. The NSIT, the 25th, is the second major storage tunnel project, Ullinger said (The first was the Ohio Canal Interceptor Tunnel). The last project is the enhanced high-rate treatment facility.
Akron has already made significant strides in improving water quality due to the projects that have already been completed in Northeast Ohio. Ullinger, who grew up boating on Lake Erie, said that in the 38 years she has been boating, she has seen the water shift from brown and murky to crystal blue.
“The thing that I like to highlight is the water quality improvements that we’ve seen just from Ohio EPA, and the data that they collect, and the habitat, the return of fish species that we’re seeing that haven’t ever been here before, is really incredible,” Ullinger said.