You have all heard of sewer backups and some of you, unfortunately, have probably experienced the problem. But what exactly is it?

First, an introductory course.  The sanitary sewer system collects wastewater from your home through a pipe called a “sanitary lateral”. This lateral carries wastewater from toilets, washing machines, dishwashers, showers and sinks to the sewer main, which carries wastewater from other homes and businesses to the City’s wastewater treatment facility.

Foundation drains collect groundwater from around the foundation of your home and are usually connected to the storm sewer by a “storm lateral”. In some older homes, these drains are connected to the sanitary or combined sewer by a sanitary lateral, or are not present.

Water from rainfall and snow melts are also collected by storm sewers and directed to nearby watercourses or storm water management ponds.

Causes of backups and flooding

Blockage of the lateral

If the lateral from your home becomes blocked, sewage from inside your home may back up into the basement. The blockage may be due to:

• Accumulation of grease, paper, kitchen waste or other foreign objects
• Presence of tree roots (private or City-owned trees)
• Collapse, misalignment or other structural defects of the lateral

Surcharging of the City’s sewer main

If the sewer main, generally located under the street, is blocked or damaged, sewage may enter your home due to increased water level or surcharging in the City’s sewer system. Sewer surcharging may be due to:

• Collapse or other structural defects
• Blockage by waste and debris. Heavy rainstorms or spring runoff.
• Construction activities in the area

Spring runoff

Melting snow and ice can leak through cracks or joints in your basement walls or floor.

Tips to prevent basement flooding

Residents can help prevent basement flooding with a few simple changes around the home:

• Seal window wells and cracks in floors, walls and the foundation.
• Slope ground away from the foundation to allow rainwater to flow away from the home.
• Direct downspouts from eaves troughs away from the foundation (minimum of 1.2 metres) or to a rain barrel(s).
• Disconnect downspouts from the sewer system or foundation drains.
• Ensure foundation drains direct water to the storm sewer or sump pump. Foundation drains should not be connected to the sanitary sewer.
• Ensure the sump pump is connected to the storm sewer or discharges to the ground at least 1.2 metres from the foundation.
• Maintain existing protective plumbing devices according to the manufacturer’s instructions. A protective plumbing device should be maintained periodically or before a forecasted heavy rainfall to ensure it is free of debris, functioning properly and that cleanout caps and access covers are firmly secured.
• In older homes, especially those with cast iron pipes, additional maintenance may be required, as rust can accumulate at the hinge and prevent proper closure of the backwater valve during a surcharge event.

For more tips on preventing basement flooding, refer to the Handbook for Reducing Basement Flooding from the Institute for Catastrophic Loss Reduction.

Jackie Beaudoin, Leclerc Insurance and Financial Services
Source :  City of Ottawa Website