Environment

A seven-foot-wide sewer pipe buried underneath downtown Louisville is on the verge of collapsing and repairs are unlikely to begin for several weeks, Metropolitan Sewer District officials say.

The threat of a cave-in has forced city officials to close down the south side parking lane and part of the sidewalk on Main Street between Fourth and Seventh streets.

Construction is not likely to begin until after Derby week as MSD strategizes how to proceed with repairs, said Sheryl Lauder, MSD spokeswoman.

“We have decided to err on the side of caution and close off the parking lanes and a small portion of the sidewalk,” Lauder said. “We don’t make this decision lightly because we realize that it is Derby time and this is the heart of our city.”

MSD

Map of parking lane and partial sidewalk of closure.

Cave-ins are nothing new for Louisville’s aging sewer system. The city’s experienced more than 7,000 collapses since 2008, but the number of cave-ins has declined in recent years, according to MSD data.

The latest pipe under threat is one of the city’s largest and carries about 40 percent of Louisville Metro’s wastewater, Lauder said. It was built in the 1950s and sits 25 feet underneath Main Street from Butchertown through downtown.

Corrosive sewer gases have eaten away at the concrete lining the inside of the pipe, exposing rebar and wearing it away, she said.

Conditions look the worst under Fourth and Fifth Street, Lauder said.

Ryan Van Velzer | wfpl.org

A view inside the Ohio River Interceptor pipe that runs under Main Street in Downtown Louisville. Corrosive sewer gases have erode the concrete lining exposing rebar.

MSD first found the problem after commissioning a study because of a cave-in along the same line last August. That cave-in ended up costing the city about $3 million in repairs and stopped traffic on parts of Main Street for weeks.

Cones placed on the south side parking lane earlier this week will be replaced Friday evening with plastic barricades to keep drivers and pedestrians safe.

Repairs to the pipe are among hundreds of projects MSD has planned as part of a federal consent decree from the Environmental Protection Agency. The mandate is designed to address overflows from Louisville’s sewer systems by 2024.

Ryan Van Velzer is WFPL's Energy and Environment reporter.