Hello,

The city works on the sewer lines in my area (because residents pour grease down the drains which cause problems).

The result to my house is that water in the toilet bowls will overflow causing a stinking mess which happens every 3 months or so. I would like to know why water will overflow the toilet bowls when the city puts pressure on the sewer lines. The same problem occurred at the house next door before they installed some kind of a device. But a neighbor of mine who lives down the street says no such problem has occurred. Anyone have an explanation? I would not know when the city started this type of work but it has gone on for a few years.

Reference a company called Rector-Seal, that manufacturers "back-water" valves to protect YOUR house from back flows due to exterior floods and water pressure caused by sewer cleaning equipment.

If your neighbors are flushing grease into the waste line, that will cause issues. Protect your property with a back-water valve. Pressures greater than 1500 lbs, combined with an equipment operator that is not observing working pressures will/can cause the issues you have experienced.

Best Wishes