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Private Sewage Systems And Flooding

Flooding of a private sewage system can be a hazardous situation for homeowners. It may result in sewage backing-up into the home and/or contaminating the drinking water supply resulting in exposure to contaminants. When flooding or saturated soil conditions persist, a private sewage system cannot function properly.

  • Before flooding
    To prepare for a flood, you should ensure the septic tank is full of liquid. Avoid pumping your tank in the high-water season. An empty tank is buoyant and may rise to the surface of the ground during flooding. Plug floor drains to keep sewage from backing up into the basement.
  • During flooding
    Discontinue use of your private sewage system, use portable toilets, if possible. If the soil is saturated and flooded, the wastewater will not be treated and will become a source of pollution. Avoid using water as much as possible while the system restores itself. Shut off power to a sewage lift pump, if you have one in the house, or in a pump chamber.
  • After flooding
    Do not use the sewage system until water in the leaching bed is lower than the water
    level around the house.
    • Signs of damage include settling or the inability to accept water. Septic tanks or distribution pipes can become filled with silt and debris, and must be professionally cleaned.
    • If you suspect damage to your sewage system, have it inspected and serviced by a licensed sewage system contractor.
    • Under part 8 of the Ontario Building Code, a licensed person is required for the construction, repairs and maintenance of a sewage system.
    • If the septic system backs up into the house, check the tank first for outlet blockage.
      Pump the septic tank as soon as possible after the flood once the soil is no longer
      saturated or flooded.
    • Do not drive or operate equipment over the area of the leaching bed. Saturated soil is especially susceptible to compaction, which can reduce the leaching bed’s ability to treat wastewater and may lead to the sewage system malfunctioning.
    • Examine the grass cover over your septic tank and leaching bed. Repair erosion damage and sod and/or re-seed as necessary to provide a new grass cover.

For further information please contact the Health Department Environmental Help Line at 1-888-777-9613

In case of a Municipal sewer back up into your home please contact the Regional Municipality of Durham Works Department.