Non Return Valve in Sewage Pipe advice please

[lancs_lad]

We have had issues with surface water backfill i the 2 recent storms, causing our foul drainage system to overflow with surface water flooding (and also our neighbours). We have had the water company out to inspect the foul sewer and broached the subject of installing a non return valve.

The guy stated that they could cause more issues than they solve so I'm wondering if this is correct.

We are at the end of the mains sewage system in our village and our surface water goes to a holding tank in the garden and then a soak away if it overfills therefore the surface water flooding issue is not of our making.

There are planning applications to build more properties opposite us and another 10 properties behind us will be connected shortly which are going to add to the issues in any future storms.

Just wondering if anyone has any knowledge of fitting non return valves and if possible if they would be willing to speak with me please regardingthe pros and cons?

 

[Agile]

Not the same but at my terrace house there are cellars at all the houses.

A neighbour had the basement converted into a bedroom anit an ensuite. But the installer did not fit a non return valve and the bedroom flooded right up to the ceiling a few years ago when the area was flooded by the river.

Another who had the same situation had a non return valve fitted to the toilet and that did not flood!