How Often Should You Pump a Septic Tank in Ontario?

Why pumping matters

Everything that leaves your house goes into the septic tank first. Heavy solids sink to the bottom as sludge, grease and oils float to the top as scum, and the clearer liquid in the middle flows out to the leaching bed.

Bacteria break down some of the solids, but never all of them. Over time the sludge and scum layers grow until there is not enough room for solids to settle. Then they start flowing out to the bed, where they clog the soil. A clogged bed is the most expensive part of a septic system to replace, and pumping on schedule is what prevents it.

What changes your schedule

Rough guide by household

• One or two people: roughly every four to five years
• A family of three or four: roughly every three years
• Five or more people, or heavy water use: every two to three years

These are starting points. When we pump a tank, we can tell you how full it was and whether your schedule should be shorter or longer.

Signs it cannot wait

• Drains throughout the house are slow
• Gurgling from toilets or drains
• A sewage smell near the tank or bed
• Wet, spongy or unusually green grass over the bed
• Sewage backing up into the lowest drain in the house

Any of these means it is time to call, regardless of when the tank was last pumped.

Keeping track

Write down the date of every pump-out and keep the receipt. If you are selling the house, buyers and their inspectors will ask for it. If you bought a home and do not know when it was last pumped, assume it is due.