Metropolitan St. Louis Sewer District

What is a Cave-In?

A cave-in typically occurs when stormwater washes soil into a defective pipe or structure. Over time, the ground or pavement above the defective pipe or structure sinks. Cave-ins can be easily identified by depressions in the soil or pavement. Cave-ins can also happen around manholes or catch basins where pipes enter the structure. To report a cave-in, contact our 24-hour customer service line at 314-768-6260.

Many cave-ins are not MSD problems. One of the most common causes of cave-ins is a defective private lateral line. Cave-ins caused by problems with the home or building's private lateral line need to be repaired by a licensed plumber or drainlayer.

Repairing Cave-Ins

After a cave-in is reported, we send a crew to secure the cave-in area in order to protect the public's safety. The crew will then conduct a dye test to determine if the cave-in is caused by a defect in the public sewer system. If the cave-in is a result of a defect in MSD's system, a field investigation is then conducted to determine the necessary repair.

Cave-ins are repaired by several methods, including:

  • Grouting the joints from inside or outside the pipe
  • Slip lining a section of pipe
  • Repair or replace the pipe or structure
  • Exposing and wrapping the failing joint with filter fabric

Prioritizing Cave-In Repairs

MSD's goal is to secure a cave-in within 48 hours of receiving the report, unless it's an emergency. We try to complete a field investigation to determine the necessary repair within one week. Depending on the type of repair, it can take between 30-60 days to repair a cave-in.

Cost of Repairing Cave-Ins

The cost of repairing a cave-in depends on the depth of the cave-in, the size of the pipe or structure, and location of the cave-in. The average cost of repairing a cave-in in the MSD public sewer system is $1,350.

In July 2010, a judge ruled that MSD's stormwater impervious rate was invalid, forcing MSD to suspend the impervious rate. The suspension of the impervious stormwater rate means that MSD's ability to respond to stormwater complaints is severely limited. Customers who reside inside the Interstate 270 corridor receive limited stormwater service. However, customers who reside outside the Interstate 270 corridor receive little to no stormwater service. This is due to limited taxes collected in that area.

The lack of stormwater funds means there is currently no money available for MSD to provide proactive prevention of cave-ins in the public sewer system. If your home or business is located inside I-270, we will typically investigate and repair the cave-in. If your home or business is located outside I-270, we will typically investigate and backfill the cave-in.

Reporting Cave-Ins

To report a cave-in or other sewer issue, call MSD's 24-hour customer service line at 314-768-6260.