A leaking sewer line has suffocated hundreds of fish in the South Fork of Beargrass Creek, according to the Metropolitan Sewer District.
MSD has pulled at least 200 dead fish from the creek, as well as trash.
Staff discovered the dead fish Tuesday while sampling creek waters near Trevilian Way and Joe Creason Park, near the Louisville Zoo.
Samples showed low levels of dissolved oxygen in the water and higher than normal temperatures.
“The wastewater has a biological oxygen need to be able to handle it and it basically takes all the oxygen out the water and fish die of lack of air,” said Brian Bingham, chief of operations.
MSD located the leaking sewer line about a half-mile upstream from the fish kill. They confirmed the source using dye tests then used a mobile camera to spot the defect in the sewer line.
After learning of the problem, MSD diverted sewage flows so the damaged pipe can be emptied and repaired. The sewage came from a heavily used sewer pipe built back in 1952.
“We have stopped the discharge and we are in the process of starting to make repairs,” Bingham said.
Signs are posted advising people not to fish, swim or wade in the area.
MSD is legally permitted to dump raw sewage into the Ohio River and Beargrass Creek to avoid sewer overflows during rain storms, but this was an unpermitted spill.
As a result, Bingham said MSD will likely face enforcement action from the state.
Louisville has a deal with the federal government to stop pouring raw sewage and stormwater into Kentucky waterways by 2024 at a cost of about $4.3 billion.
This post has been updated.