Sewer Education

Normally, wastewater will flow from the pipes in your home and to the main sewer pipe in the street. The flapper opens to allow the wastewater to flow.

If the main sewer pipe is full and starts to rise— which can happen in the event of a major blockage — the flapper closes to allow prevent water from flowing up and into your basement.

When the backwater valve closes the sewer line, you should NOT use the toilet, sink, shower, washer, or dishwasher. Until the flap is reopened, the wastewater will have nowhere to go except up the floor drain and into your basement.

A backwater valve is usually installed in the basement floor near the front of the house and typically in-line with the stack from the floor above. A plumber can also complete an inspection for you to confirm if you have a backwater valve or not.

If you can't locate your backwater valve, your home might not have one or it may be covered. Backwater valves were not required in homes built before 1989. A backwater valve is important to protecting your home, and you should consider installing one if not already done. You may want to discuss with your insurance provider to find out if your premiums can be adjusted if a new backwater valve is installed.

There are different types and costs for backwater valves. Private plumbers can provide you with a cost quote and install one that's right for your home. A plumbing permit is also required.

Checking and cleaning your backwater valve is a good way to reduce the risk of basement flooding. At least once a year, flush, clean and exercise the valve to ensure it moves easily. Do not cover the backwater valve with carpet, flooring or any other permanent structure.

• Locate your backwater valve and remove the plug or panel.
  Shine the flashlight around the area and look for debris. Debris stuck in the gate can cause the sewer backwater valve to stop working.
• Clean the area. Flush the valve with a bucket of water to clear debris from the gate area. If that doesn't work, scrub the area to remove it.
• Once clean, move the gate back and forth to make sure it moves without any problems. If it's stiff or you see rust, oil it a little bit.
• Check the O-ring on the backwater valve. If it's cracked or damaged, replace it.
• Replace the plug or panel on top of the valve.

Remember to follow good hygiene while cleaning the valve. We recommend you use rags to protect your floor and to wear gloves and eye protection while working. Wash up any tools. Paper towels can be composted; shop cloths and other disposable materials and gloves should go in your landfill container. Do not flush these materials!