: I live in a 18 year old house built with a wood foundation. Sometimes, especially in winter, we have a sewer odor in the entrance level and the basement (where the sewer pipes run to the public system). It is very unpleasant and embarrassing. I have consulted the builder and a plumber who cannot identify the problem and solution. Can someone help?
I would begin by reporting it to your public agency that oversees it. It might be a leak but if you've had people look at your system without finding anything, more than likely, there is a problem with the public system. It could be a high place in their line which is not letting the fumes to relief valves and backing them up to your house and probably others as well. I recently did a survey for a local city who indeed found a high place which was blocking the escape of the fumes to their vents.