We have a problem with our waste coming out on our sidewalk, through the sewer pipe. Our neighbor had the same problem. She had to have the Street and side walk tore up to the main Sewer line. She had a One Way Flow Valve Installed. Three houses on our block are having problems, two inside of their home. We are the only ones with overflow on the side walk. We are right next to the home who installed the One Way Flow Valve. All of this started days after installation of the valve and at the same time of a heavy rain. The contractor that we spoke with said that it is unusal to install a One Way Flow Valve, and that they must suspect that there is a problem with the City or the Main line. He said that our problem will not go away and will continue with heavy rain and snow, due to the installation of our Neighbors One Way Valve. Our neighbor spend over $20,000 to have the problem fixed. Now it is our problem. Please advise me what to do. The city is not taking this problem seriously. Should I call the Board of Health? What is a One Way Flow Valve?
Thank you.

Your home must be at a slightly higher elevation than your neighbors that install the back water valve(One way). A back water or check valve allows water to only flow one way, from you house to the street. Not from the street to your house. There is a blockage or some problem in the city main sewer line. When your neighbor installed the valve the sewage can no longer come out in their house, so it now backs up to yours. If you install a valve the sewage will back up to the next person's house. Call the city and insist that they clear the main line. That thing in the side walk is not an overflow, it is a clean out, a place for snaking out your sewer line to the street. It should be sealed. The cap must be missing. If you cap it the sewage will probably back up inside your home.

It's the citys problem for allowing rain water run off to connect to the sewer main and overload it. The solution, as Herald suggested, would be to install your own back flow preventer/ house check valve,(see image) and cap off the open pipe at the side walk. Good luck, Tom

We are talking about a sanitary sewer line and not a storm water drainage system aren't we?

Harold, I think they're talking about a combined sewer and rain water runoff set up that backs up every time it has a hard rain. Regards, Tom