Replacing a septic system in Ontario takes 6 to 10 weeks from the day you call a contractor to the day your new system passes final inspection. That window covers soil testing, permit approval, excavation, installation, and sign-off by your local building authority. If you're planning ahead, it's manageable. If your system is actively failing, it feels long. Either way, the process is the same, and the more you understand it before you start, the fewer surprises you'll hit.

Most Ontario septic systems last between 20 and 40 years, but that range depends heavily on what's in the ground, how the system was maintained, and which component you're asking about. The concrete tank and the leaching bed have very different lifespans, and it's almost always the bed that goes first.