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 just west of the intersection of West Drive and North Drive. The break was reported to MSD by the property owner at approximately 2:00 PM yesterday. The break is NOT leaking into any waterway and is being contained on the property. However, pump stations upstream of the break were shut down earlier today to allow for repairs. Shutting down the pump stations is causing overflows at manholes upstream of the force main break. The manholes began overflowing at 4:00 PM today. Affected areas 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 design. Construction of the replacement force main is scheduled to start in 2016 at an estimated cost of $6.5 million. However, MSD is evaluating how this project might be accelerated and expects to share these plans within the next 4 to 6 weeks.
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.