Crews and contractors with the Metropolitan St. Louis Sewer District, or MSD, are working to repair an underground force main sewer break on Meramec Bottom Road in south county.

The break at 4660 Meramec Bottom Road occurred at 10:30 a.m today. A construction crew, contracted by MSD, was conducting soil boring and core sampling for the Lower Meramec Tunnel Project when it drilled into a force main sewer that was not properly marked, causing it to break, according to an MSD news release.

The break of force main leaked into an open field that is owned by MSD and into an unnamed tributary the flows into the Meramec River. The leak has been contained to this area, while the crew onsite makes repairs.

Repairs began immediately. However, it is estimated that over 50,000 gallons of sewage has entered the creek. As a result of the force main break, MSD has shut down a pump station upstream of the break to allow for necessary repairs. Shutting down the pump station will cause overflows, but this will not affect sewer service in the area, the release stated.

MSD is placing warning signs in these areas, advising the public of the overflows. While there is no immediate threat to public health or safety, the public is asked to heed the signs and avoid contact with the affected areas. If a member of the public should come in contact with these areas, they should immediately and thoroughly wash with soap and water.

MSD will monitor manholes throughout the area. If a member of the public should come across what they suspect to be an overflowing manhole, contact MSD’s 24-hour Customer Service Center at (314) 768-6260.

Repairs to the force main are ongoing and could take up to 48 hours to complete. Once repairs are complete and full operations of the force main sewer resume, cleanup at the break and associated overflow locations will commence.

A force main sewer is a sewer line through which wastewater is propelled by the force of pump stations located along the path of the sewer. Pump stations are sometimes necessary to overcome gravity and allow for the transport of wastewater to area treatment plants. Force mains are made of cast iron and can last anywhere from 25 to 50 years, depending upon the amount of flow the line handles and the corrosive properties of the wastewater.

The force main sewer break and associated overflows at the manholes have been reported to the Missouri Department of Natural Resources, as required by law.