Precautionary Sewer Backup Advisory Issued for Area Near Broadway and Biddle Street Collapse

MSD Project Clear (MSDPC), in consultation with Unified Command, today issued a precautionary advisory for the properties in the area of the water main break and street collapse and near Broadway and Biddle, where subsequent damage to a 12-foot-diameter sewer main may increase the risk of basement backups during rain events. People in the highlighted advisory area near North Broadway and Biddle (see map below) should take precautions to protect basement belongings from a higher-than-normal risk of sewer backups during rain until repairs are complete.

MSD Project Clear has reviewed available system information and field conditions to identify, to the best of its ability, the areas believed to be at greater risk until repairs are complete. Because this is an unusual emergency situation, no model can accurately predict every location where a backup might occur. The map, therefore, should be understood as a best estimate based on current conditions, not a prediction, and may change.

The map identifies three levels of increased risk for backups during heavy rainfall:

• Zone 1 (Red): Area believed to have the highest increased risk
• Zone 2 (Orange): Area believed to have a moderately increased risk
• Zone 3 (Yellow): Area believed to have a low but increased risk

This increased risk is expected to continue until the sewer main is repaired and returned to service. The timeline for return to service is not yet known and will depend in part on efforts to stabilize the hole and protect the interstate.

Properties outside the mapped area may also experience sewer issues, particularly during heavy rain, and not every property within the mapped area will necessarily experience a backup. The map will be updated if conditions change or additional information becomes available.

MSD Project Clear is taking all available steps to reduce the risk of basement backups and ensure the surrounding sewer system operates as effectively as possible while repairs are underway. This includes inspecting open sewer lines in the area, installing bypass pumps to move water away from the affected sewer main, and taking other operational steps to maximize available capacity. The City of St. Louis Water Division is coordinating with MSD Project Clear to avoid draining or relieving water mains into the sewer system while the 12-foot sewer main remains out of service. MSDPC will have additional crews on standby during forecasted rain this week.

These steps will help reduce the risk, but they cannot fully replace the capacity of a 12-foot sewer main during heavy rainfall.

In addition to the proactive steps MSDPC is taking, property owners in the mapped area are encouraged to take precautions now and keep them in place until repairs are complete, especially when rain is in the forecast. Recommended precautions include:

• Move valuables, important documents, electronics, and irreplaceable items above basement level where possible.
• Elevate items that cannot be moved out of the basement.
• Avoid storing items directly on basement floors until repairs are complete.
• Minimize water use during rain where possible, including delaying laundry, dishwashing, long showers, or other non-essential water use until after the rain has passed.
• Avoid contact with sewer water. Do not enter flooded areas if electrical hazards may be present.

Anyone experiencing a sewer backup should:

• Avoid contact with sewer water.
• Stay out of flooded areas if electrical hazards may be present
• Call MSD Project Clear's Customer Service team at 314-768-6260.
• Call 911 for life threatening emergencies