Why Is My Septic Tank Backing Up into the House?

Few things are worse than sewage backing up into your home. If your toilets, sinks, or tubs are overflowing with wastewater, it’s a sign of a serious septic issue that needs immediate attention.

One common reason for backups is a full septic tank, which happens when the tank hasn’t been pumped in several years. However, if your tank has been pumped recently and you’re still experiencing backups, the problem could be clogged pipes, drain field failure, or even damage to your system.

For homeowners in Edmonton, Lac Ste. Anne County, Parkland County, Sturgeon County, and Strathcona County, Alberta’s cold climate and unique soil conditions can make septic problems worse. Below are the most common reasons your septic system might be backing up into your house - and what you can do about it.

1. A Clogged or Damaged Pipe

Your septic system relies on pipes to move wastewater from your home to the tank and from the tank to the drain field. If one of these pipes is clogged, collapsed, or blocked, wastewater has nowhere to go and will back up into your house.

🔹 Solution:

  • If only one toilet or sink is backing up, the blockage may be in the household plumbing. Try using a plunger or drain snake.

  • If multiple fixtures are backing up, the clog is likely in the septic pipes. A septic professional can inspect the pipes and clear the blockage.

  • If the pipe is damaged or collapsed, it may need to be replaced.

2. The Drain Field Is Failing

Your drain field is designed to absorb and filter wastewater from the septic tank. If the field becomes clogged, flooded, or compacted, water won’t drain properly and will back up into your home instead.

Signs of drain field failure:

  • Sewage backups in toilets, sinks, or tubs

  • Slow drains throughout the house

  • Wet, spongy ground over the septic field

  • Bad odors coming from the yard

🔹 Solution: If your drain field isn’t absorbing water properly, it may need to be restored, repaired, or replaced. A septic expert can inspect your system to determine the best course of action.

3. Freezing in the Septic System (Winter Backup Issue)

In Edmonton and surrounding counties, harsh winters can freeze septic pipes, the tank, or even the drain field, preventing wastewater from flowing.

If this happens, you may notice:
✔️ Gurgling sounds in the pipes
✔️ Toilets and sinks draining slower than usual
✔️ Water backing up inside the home

🔹 Solution:

  • If the system is frozen, avoid using water until a professional can thaw the lines.

  • To prevent freezing, septic lines should be buried deep enough and insulated properly.

  • If you live in an area with extreme winters, adding straw or foam insulation over the system before winter can help

4. Excess Water Overloading the System

Septic systems can only handle so much water at a time. If too much water is used at once—such as running multiple loads of laundry, taking long showers, and using the dishwasher all at the same time—it can overwhelm the tank and drain field, leading to backups.

🔹 Solution:

  • Space out water usage throughout the day to avoid overloading the system.

  • Fix any leaky faucets or running toilets, as they can send gallons of extra water into the system each day.

  • If your household size has increased over the years, your septic system may be too small and need an upgrade.

When to Call a Septic Professional

A sewage backup is a serious problem that won’t fix itself. If you notice water backing up in your home, slow drains, or standing water near your septic field, it’s time to call a professional. At S.A.C. Septic Solutions, we help homeowners in Edmonton, Lac Ste. Anne County, Parkland County, Sturgeon County, and Strathcona County diagnose, fix, and (if needed) replace septic systems. If your septic tank is backing up into your house, contact us today for an inspection and expert solutions.