GREENVILLE, S.C. (WSPA)–The Dig Greenville project is well underway, tunneling more than a mile directly under the city. It’s to expand sewer capacity to match Greenville’s rapid growth.
Lowered a hundred feet underground to the mouth of the tunnel, 7News was given an inside look at the work.
“They’ve mined about 3300 feet so far so they’re about halfway done,” Horry Parker Jr., Resident Project Representative with Black & Veatch, said.
The project is about two years in, and when completed, will bring the sewer system on par with the growth Greenville has seen.
“We have to continue to be able to have the infrastructure to handle the growth that we’re having in Greenville,” Tim Brett, commissioner with ReWa, said.
“This just gives us a more reliable sewer system as we go into the future,” Jason Gillespie, senior project manager with ReWa, said.
The tool that’s digging through this solid rock is called a tunnel boring machine, or TBM.
“We anticipate they’ll be mining through this solid rock until they reach the other side,” Parker said.
The technology uses disk cutters that make creating the tunnel much more efficient.
“It can get about 40 to 50 feet a day. As a comparison when we were blasting it out we could get one or two feet a day,” Gillespie said.
And with nearly no impact to the city above.
“So this really helps us minimize the impact to the public to do it this way,” Gillespie said.
It’s a project county councilman Lynn Ballard was glad to see firsthand.
“To just think about how this is going to really improve the storm water runoff and things once the sewer is done and we get the pipes in.”
He said one of the areas that will be helped by an expanded sewer system is nearby Cleveland Park.
“So the pipes just weren’t big enough to handle it so this is going to take care of a lot of those type problems,” Ballard said.
When completed, the tunnel will stretch more than a mile under the city. No one will see it but its benefit to the people living above will be exponential.
“The water goes away and it gets treated and it gets put back in the river so it’s all about clean water its all about the environment its all about safety so when its finished things will work and we’ll have added capacity but you won’t know what’s underground,” Brett said.
In just about a year, the tunnel will be finished and the sewer will be flowing through it. When it’s completed, the system is expected to alleviate problems for at least the next 100 years.