Part 3 of 3: Fort Wayne Underground

$150 million tunnel will reduce sewage overflows

FORT WAYNE, Ind. (WANE) – A tunnel running more than five miles in length, at least 12 feet in a diameter, and more than 150 feet below ground, will play the biggest role in Fort Wayne’s effort to remove the amount of untreated sewage in the city’s waterways.  Construction on the tunnel is expected to begin in 2017.

A series of special reports on NewsChannel 15 and WANE.com has looked into the work the city has done, and still has planned, that will make drastic improvements to reducing the raw sewage that gets dumped into Fort Wayne’s waterways.

The one project making the biggest impact is the Three Rivers Protection and Overflow Reduction Tunnel.  The tunnel’s construction will cost at least $150 million, while its design will cost approximately $30 million.

The tunnel is expected to be completed between 2023 and 2025.

“We currently have 43 locations in our wastewater system that have combined sewer overflow points,” said Matt Wirtz, the city’s Deputy Director of Engineering.  “Those locations are where we discharge raw sewage into the rivers.  A majority of them are along the Maumee and St. Mary’s Rivers, which are the mostly oldest areas of our system.  We’re working to reduce those overflows with this tunnel project.”

Though the tunnel’s exact path is still being determined, the work on it will begin at the city’s wastewater treatment plant on Dwenger Avenue.  From there, it will head west, along the Maumee River, before heading south along the St. Mary’s River.  It will end near Foster Park.

Another tunnel, called the Foster Park Relief Sewer, will be built south of the park.  It will serve as an upstream extension of the tunnel, and is two miles long and between 48 and 84 inches in diameter.

“We’re trying to keep the [3RPORT] tunnel as close to those overflow points as possible, which were along the river,” Wirtz said.  “The tunnel will be generally following the river.  As of right now, we’re looking in the 150 to 250 foot depth for the best limestone.  We’re trying to find layers of limestone that are really tight.  Not very many cracks, so there’s very little ground water to deal with.”

NewsChannel 15's Randy Spieth joins Fort Wayne engineers to visit Indianapolis' sewer tunnel back in late May.
NewsChannel 15’s Randy Spieth joins Fort Wayne engineers on a visit of Indianapolis’ sewer tunnel back in late May.

To give an example of how far underground Fort Wayne’s sewer system is right now, Wirtz said the city’s deepest pipes currently run about 40 feet below ground.

Fort Wayne engineers have done soil boring tests along the rivers to help determine the best depth.  They have also visited Hanson Aggregates-Ardmore Quarry to look for limestone with the fewest cracks.

The city can save money by finding solid rock with little cracks because less groundwater will get to the tunnel, which will have a concrete liner once it’s drilled.

The tunnel’s main purpose will be to collect water during and after heavy wet-weather events, such as rain storms or snow melts.  Currently, the city’s combined sewers handle the excess water by dumping the overflows into local waterways.  Once the tunnel is up and running, that stormwater will fall into the tunnel, where it will make its way to the city’s wastewater treatment plant to be treated and then released into our waterways.

“The goal is to create enough of a capacity in the tunnel to capture most of the rain that happens in our system, as well as, most of the sewage overflows that happen into the river, and convey that to our treatment plant,” said Kumar Menon, Fort Wayne’s Director of Utilities.  “That’s instead of just dumping it into the rivers or leaving it the streets, or more unfortunately, in people’s basements”

City officials said they believe they’ve eliminated basement backups for 6,500 homes.  “Over the next 15 years, we’ll continue to reduce that even further,” Menon said.  “The tunnel is a big part of that.”

In late June, Fort Wayne’s Board of Public Works approved design contracts totaling over $15 million.  “It is safe to say phase one is done,” Kumar Menon, Fort Wayne’s Director of Utilities, said.  “We came in ahead of schedule in some projects, under budget on some projects, and we hit every single milestone that was imposed on us.”

Fort Wayne Council approved the Public Works’ decision on Tuesday night.

While Fort Wayne won’t break ground until 2017, Indianapolis is approximately a fourth of the way done with digging its more than 25-mile long tunnel.

In late May, NewsChannel 15 joined Fort Wayne engineers and Allen County workers on a tour of Indianapolis’ Deep Rock Tunnel Connector, which is located approximately 240 feet below the Earth’s surface.

“We know that it’s very beneficial to come down and see how the project works, what kind of area you need, and really how it affects the community during construction,” Mike Miller, who has been managing Citizen’s Energy Group’s construction of the first leg of Indianapolis’ tunnel.  “Other communities around the U.S. did this for folks at Indianapolis when we were designing outs, so it’s a little bit of a way to give back.”

To get inside the tunnel, visitors must go through a short safety course.  Visitors get to the tunnel by going in a cage that is attached to a crane.  From there, the crane lowers the cage through a large hole where construction began.  The hole was used to lower the tunnel boring machine, which drills the tunnel’s path.

Indianapolis has broken its project into five sections.  The first leg was being dug when NewsChannel 15 toured the site.  Construction began at the city’s wastewater treatment plant near Southport Road, located on the city’s southern edge.  The tour took visitors a few hundred feet through the tunnel.  At the time, the tunnel was over five miles long.

“Tunnels are such a unique infrastructure,” said TJ Short, Fort Wayne’s senior program manager for sewer design.  “Not every city has a tunnel.  They are so rare.”

Short has toured the sewer tunnel project in Indianapolis and Columbus, Ohio, and said there is a real value for seeing the projects in person before trying to construct your own.

“When you’re there, it’s like, wow, this is a lot bigger than I thought,” Short said.  “It has a different feel.  Wow, there’s water up to your ankles.  There are a lot of things that you don’t anticipate until you’re actually in the hole.”

City engineers aren’t the only ones touring the Indianapolis site.  Leaders with the Fort Wayne Fire Department are expected to make a trip later this summer to help avoid a tragedy like the one back in June when a worker inside the Indianapolis tunnel was killed.

Fort Wayne engineers have estimated work on the tunnel will total more than 80,000 hours between everyone who contributes to the tunnel’s completion.  The project will also bring a big boon to the local economy.

“Most of the work is going to be done by local firms,” said Menon.  “It allows a lot of knowledge transfer to happen between the private and public sector.  Our folks get trained by folks who have a lot of experience around the globe.  They bring their talents and expertise here and transfer some of that knowledge to our folks.”

 

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