NASHVILLE, Tenn. — The tunnel the Boring Company is cutting from downtown Nashville toward the airport reached the area near the Music City Center this week, and a new report warns the hardest ground is still ahead.
Published Oct. 21 on behalf of the Southern Environmental Law Center, the study comes from Chris Groves, a hydrogeology professor at Western Kentucky University, and it lays out three main dangers in the city’s soluble limestone: sinkholes opening at the surface, water flooding into the tunnel and pollution spreading through groundwater. The work near the convention center suggests the company has finished as much as one tenth of its route.
Four limestone layers sit beneath the planned path of the parallel tunnels. The company intends to stay mostly inside the Hermitage Formation, which is mixed with harder minerals and dissolves less easily. The report says that layer has worn away entirely in places, so the tunnel will have to pass through the Carters Formation beneath the Cumberland River and two creeks, Mill and Browns, where cave and void features are most developed.
The study also points to the former Aladdin Industries site on Murfreesboro Pike, where arsenic, cadmium and lead have been driven deep into the soil. Digging beneath contaminated ground could push those metals into the water table, the center argues.
The company published its own environmental assessment late last year. Of its 150 pages, fewer than 10 deal directly with water, safety or geology, and it cites only studies from 1958 through 1990. State environmental regulators did not require a permit. Metro Councilmember Clay Capp, who reviewed the study, called the company’s environmental material inadequate and said the project could still be canceled.
Tunneling under Nashville began in February. The company had not answered questions about the findings.
