[1_Rain_Drop]

"first house I ever bought in Manitoba... after 2 days in house, city sewage backed up into my basement. They had crushed the sewer pipe when they were working on something else. Needless to say it was a disaster. Now my rule of thumb is.. if there is no check valve, install one."

Thanks for the advice.

My concern is if the main sewage holding tank cracks or shifts, the damage won't be visible when it happens because it would happen underground. That plant will be 200 feet from my house. The water that floods the cellar yearly would be contaminated with sewage which may not be detected because it would be diluted. If a pipe bursts, then that's a different story. I would have immediate proof.

[Bulwyf]

You get yearly water in the cellar? Yes, I can see how that would be a cause for concern. If it’s not leaking in through any pipes, a check valve won’t stop that, having foundation repaired would though if it’s a concrete basement.