Towns sewer line backs into my main line.

what is the purpose of a check valve? I'm getting city sewer backup and the city suggest this instead of fixing problem in main line. There are roots growing in the main and the tree is a very big willow(most likely) about 100 feet away on private property. The main gets plugged up several times a year and the town says the will just ream it out. If a pipe has already been compromised with roots , wouldn't the reaming process further weaken it. If I put in a check value won't I still get backups(my own) from washing machine overflowing my toilet. Currently I took the sewer cap off in the cellar , so if I have backup it goes there. Then I call the town and they blow up the lines. If I leave the cap on my first floor toilet will overflow and I get all the waste backing up into my living room. The town health board says its not their problem. Any suggestions
thanks Steve

sewer

I would tell the town that it is their problem. In this area if a backup is caused by the city sewer system being plugged, the city will reimburse for any damages, and if you called plumber first, thinking it was your sewer, they will also cover that.

Deb

A backwater valve will create exactly the problems you have mentioned.
I am concerned about the sewage in your cellar, this is a real health hazard (although I understand that this is better than in your living room).
Are you the only one with this problem (there is strength in numbers)?
If your assessment of the situation is correct, I would get a licensed plumber to give you written verification and start raising h*ll. Regardless of what the town health board tells you, I am certain that there must be some regulation regarding the proper maintenance of the town sewer system.
This really is an untenable situation that I am sure there is a solution to.
Deb
The Pipewench

State Board

It sounds like you live in a small town. They do not always have a clear understanding of their responsibilities and are very budget minded. I would call your State Environmental Health department. This is the town's problem and should not be yours.

sewage

The county health board might be the next step above the city/town/village health or sewer department.