MSD's underground tunnel project hits delays, goes over budget

LOUISVILLE, Ky. (WDRB) -- Louisville’s Metropolitan Sewer District has requested a deadline extension from the United States Environmental Protection Agency for the city’s Waterway Protection Tunnel.

The four-mile tunnel runs 18 stories underground and is designed to prevent sewage from overflowing in the city’s waterways during significant rain events. The tunnel should capture approximately 439 million gallons of overflow during the typical year. The tunnel is one of several projects in the city’s more than $1 billion plan to meet the federal consent decree.

The original deadline was to have the tunnel operating by the end of 2020. However, the team hit a few roadblocks while excavating the tunnel that delayed the project. MSD requested an extension from the EPA before the end of the year, and a spokesperson said the department is hopeful the EPA will grant it.

MSD project manager Jacob Mathis said the tunnel project is about 75-80% done right now. The original estimated budget was $200 million, but that has gone up to $214 million now.

"Getting through the excavation was the hard part, because that's the unknown," Mathis said. "You don't know what in front of you as you're digging."

One of the setbacks included hitting more loose rock than initially expected in three areas. The tunnel is deep enough under the city that the majority of the excavation was through limestone. However, there were a few spots where there was some excess loose rock that fell from the crown of the tunnel. For the safety of the crew and the project, the rock needed to be broken up and hauled out, which took some more time.

Mathis said crews also hit a pocket of natural gas just a few hundred feet from the end point of the tunnel near the intersection of Lexington Road and Grinstead Drive. That required the contractor to shut the machine down for four days, Mathis said, in order to let the gas vent out before starting to dig again.

Finally, the coronavirus pandemic was partially to blame for the others delay to the project. Mathis said there were certain pieces of equipment and parts that were ordered from overseas, but manufacturing delays prevented those parts from getting to Louisville on time, slowing things down even more.

The boring machine, nicknamed the Bumblebee in honor of Muhammad Ali, started digging the tunnel in January 2019 and reached the end point in September 2020.

"Myself as well as the rest of the staff are very proud of it," Mathis said, referring to Bumblebee. "It is a big accomplishment in our consent decree, and it's been a lot of work for a lot of us."

Since then, crew members have been pulling the machine apart and bringing it back up to the surface, piece by piece. It will take 55 tractor trailer loads to haul the machine back to Pennsylvania.

By the end of the week, all the equipment and debris should be cleared out of the tunnel. Then crews will start on one of the final phases of the project: lining the tunnel in a 12-inch layer of concrete. The concrete lining will prevent any groundwater from seeping into the tunnel, and it will prevent any loose rock from damaging the tunnel or pumps.

The tunnel is now expected to be functioning sometime this fall. Mathis said crews will still be cleaning up and doing above-ground work well into the spring of 2022.