Crews and contractors with the Metropolitan St. Louis Sewer District (MSD) are working to repair an underground force main sewer break in Chesterfield, Missouri.
The location of the break is 14775 Howard Bend Station Road in Chesterfield. The break was reported to MSD at 7:00 AM by contracted crews working onsite to construct a new force main to run alongside the existing in-service force main. The break of the in-service force main is leaking into a ditch and the leak is being mitigated near the break. However, pump stations upstream of the break were shut down earlier today to allow for repairs. Shutting down the pump stations will cause sewer overflows. Affected areas potentially include:
• Caulks Creek near the intersection of Crystal Spring Drive and Brighthurst Drive in Chesterfield.
• Portions of the walk/bike trail that runs along the Monarch Chesterfield levee south of Chesterfield Commons.
• Other portions of Caulks Creek.
• Portions of Bonhomme Creek.
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, they should contact MSD’s 24-hour Customer Service Center at (314) 768-6260.
While the pump stations are shut down, and to lessen the amount of wastewater that overflows from manholes, MSD is using vacuum trucks to transport the sewage at the pump stations to MSD’s Missouri River Wastewater Treatment Plant. The trucks are equipped with large storage tanks and will vacuum up the sewage as it accumulates at each pump station. Once a truck is full, it will leave for the treatment plant and another truck will take its place.
The suspected force main break and shutting down the pump stations will not affect sewer service to homes and businesses in the area.
An estimate on the time needed for repairs will be provided once the underground force main is fully excavated and the needed fix is identified.
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 in question was built in 1983 and a replacement is currently under construction. Construction was accelerated to expedite construction of the new force main alongside the existing main.
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.