MSD is repairing a sewer main break in Oakville that sent sewage into the Mississippi River Sunday.

The Metropolitan St. Louis Sewer District said around 9 a.m. Sunday that the underground force main sewer break would take 24 to 48 hours to fix.

The break happened near Christopher Drive and Nellie Avenue in Oakville and was reported to MSD Saturday by a property owner.

MSD shut down a pump station upstream of the sewer break so that repairs could be made in light of the sewage flowing into the river.

Sewer service to homes was not affected, MSD said.

MSD placed warning signs in the area to warn affected customers to “avoid the affected area,” the sewer district said.

“While there is no immediate threat to public health or safety, the public is asked to avoid this area while MSD crews make the necessary repairs,” MSD said in a news release. “If anyone should come into contact with the overflow, they should immediately and thoroughly wash with soap and water.”

The sewer break was reported to the Missouri Department of Natural Resources, as required by law, the utility said.