How could a sewer backup affect me?

If the backup occurs in a City-maintained line, the wastewater will normally overflow out of the lowest possible opening. In some homes – especially those with basements, or where the lowest level is even with the sewer lines – the overflowing wastewater may exit through the homeʼs floor drains. If the backup only happens when you use water, and it slowly drains when you stop using water, the problem is most likely in your sewer lateral.