Massive ‘Dig Indy’ tunnel project getting bigger

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INDIANAPOLIS, Ind. (Feb. 18, 2015) - The cavernous “Dig Indy” tunnel project currently underway beneath the streets of Indianapolis is on the verge of growing even larger.

Since 2013, Citizens Energy and contractors have been working to dig five huge tunnels staring near the intersection of Southport Road and South Tibbs Avenue, extending along the White River, Fall Creek, Pogues Run and Pleasant Run.  The 25 miles of tunnel will eventually hold massive tanks that will hold 250 million gallons of raw sewage.

“We know that about 5 to 6 billion gallons of raw sewage goes into our rivers and streams each year,” said Citizens Energy Group spokesperson Sarah Holsapple.  “And we’ve been tasked by the Environmental Protection Agency to fix that problem.”

The Dig Indy project, which is in response to the Clean Water Act of the 1970s, is still about a decade from full completion.  But in the next couple years, contractors are planning to add a sixth tunnel beneath Eagle Creek, which was not in the original design.

Citizens Energy had scheduled some combined sewer overflow work on the surface to catch sewer runoff into Eagle Creek.

“The original concept was for a soft ground interceptor project that would have impacted businesses, residents, and potentially interfered with some of the city’s flood control system,” said construction manager Mike Miller.

But not long ago, project managers got the idea of using the massive boring machine, which was already underground, to dig a new tunnel instead of working on the surface.  The contractor that operates the huge digging machine was literally able to put it in reverse, go back through existing tunnel, and start working on the new Eagle Creek section.

“So what we’ve done now is we’ve designed an extra tunnel that’s 2 miles long that will store 17 million gallons of raw sewage,” Holsapple said.

Aside from adding an extra 17 million gallons of sewage storage capacity, the new tunnel will mean no disruption on the surface around Eagle Creek.  Residents and businesses in the area won’t even know the work is happening 240 feet below their feet.

“So you can be driving or walking along the tunnel system and not even feel the vibrations from the boring that’s going on under your feet,” Holsapple said.

The other benefit, Holsapple says, is that the money that would have been spent on the surface projects will now go toward the new section of tunnel.  So the new, sixth tunnel will be done at no extra cost to the overall $180 million project.

The Eagle Creek tunnel is expected to be finished by the end of 2017.  As each section of the overall tunnel is finished, the huge tanks will be installed and sewage will be stored.  The overall Dig Indy project is due for completion by 2025.