What causes basement backups from storm water?
Sanitary sewer basement backups can be caused by a variety of factors. Often times, basement backups occur during heavy rain storms. This is due to the fact that the sanitary sewer systems are inundated by an overabundance of rain, or "grey" water. In Biron, the sanitary sewer system is separate from the storm sewer system. This means rain water is entering the system through either inflow (direct connection to the sanitary system), or infiltration (water entering the system through an indirect source).
Inflow
- Roof Drain Connection
- Uncapped cleanout
- Storm sewer Cross-connection
- Illegal foundation drain connection
Infiltration
- Root intrusion into lateral
- Cracked or broken laterals/mains
- Defective manholes
- Defective lateral connections
If the property having issues with backups during rain event have a sump pump, the sump pump may be overloaded. A backup may also occur if the power goes out during a heavy rain event. The sump pump system is designed to keep groundwater out of the basement, but can also act as a conduit to bring water in.
Storm water sump pumps are basement pumps, which remove water that collects below a basement slab floor and pump it to an outlet in the yard. These pumps are normally electrically given. Therefore, the pumps will not function during a power outage. If the power outage occurs during a rainstorm, water that collects in the footing drains of the residence cannot be pumped out
Preventing Basement Backups From Storm Water
There are several measures a property owner can take on their own to reduce the risk of basement backups.
Grading
One of the simplest things you can do to help keep water out of your basement is to make sure the dirt next to your home is properly graded, meaning it is pitched, or sloped away from the house.
Sealing Cracks
Seal cracks in concrete next to your house, such as where a sidewalk meets your building, with something like a polyurethane sealant. Doing so can help keep water out of your basement.
Extend Downspouts
Make sure the downspouts on your home or building are extended at least six to ten feet away from your basement. Every downspout can deliver up to 12 gallons of water a minute during a heavy storm, water you do not want causing damage to your basement. Be sure the downspouts are not connected to the footing drain, which collects water around the foundation along the basement walls. The sump pump typically pumps the water collected in the footing drain to the rear yard, often with a connection to a rear yard storm sewer.
Back Up or Increase Size of Sump Pump
You can install a larger sump pump, or get a backup system for your sump pump. When you lose power at home, your sump pump becomes useless, unless you have a backup system. Battery backup systems can buy enough time to get a generator running, or to borrow a generator for longer periods without power. Make sure the discharge pipe from your sump pump is at least six to ten feet away from your house.
Illegal Connection
If the storm water sump is connected to the private sanitary sewer rather than discharging water from the footing drains to the yard, the sanitary sewer can fill up with storm water. The sanitary sewer was not sized to handle the additional flow from the footing drains. Therefore, sanitary backups in homes and manholes may result.
Other examples of illegal connections to sanitary sewer include:
- Downspouts
- Patio Drains
- Rear Yard Drains
- Removing covers off sanitary sewer manholes
More Information
Read Village ordinance 13.26 Use of Public Sewers to learn about what you should and should not discharge into the sanitary sewer.