I have a high water table under my home and during certain times of year water enters my main trap through an intentionally cracked cleanout cap (only One) for the last 57 years. I own home last 23 years and occasionally would get slight sewer gas smell but recently overwhelming... I had to cap cleanout and when I removed cracked cap there seemed to be hugh draft of gases coming from city side. My trap is OK / water present and gas smell entering home only here. Years ago a plumber suggested sealing and trying to add a stump pump in this below grade area to never have any gas smell issues but very small area and would probably be extensive work.
THIS setup with cracked cap has worked for almost 57 years when needed (very wet periods of fall/winter thaw/extremely heavy rains) and I want to know WHY gas DRAFT has incresed so dramatically?? Can I have issue with line outside foundation to street or city issue/clog.
This water is seasonal and stops during spring/summer and had tested years ago as possible water source from another home/city or my main and no fluride present... truely high water table issue.
ANY suggestions on why gases now entering home /gas pressure increase from city side??
Know not ideal situation but worked since home built and during dry months can be capped but I would need to monitor or would have flood in family room side of lower level of house /other side concrete crawl space.

THANKS for any suggestions

Hi Mike

Best option here is to install a sump pump... hands down your best solution, OK?

With that being said, my only thoughts on the increase in pressure is that there has probably been an increase in the number of homes using the old sewer system. Maybe there is a new development or two nearby that has increased volume to the sewer system?

There could also have been some changes to the city/town sewer system. For example, they could be relining the pipes in the street, or they could be cleaning the drains in your neighborhood? That kind of stuff. Here, a simple phone call over to your local city/town sewer dept. could tell you more, but I wouldn't mention anything about the sump pump or water drain issue. Just tell them you opened the cleanout to snake your drain as routine maintenance and you noticed the increase in pressure compared to other years... see what they say!

Finally, you mentioned a TRAP. Does your home have a main house trap? If so, then I would think that would eliminate the issue as being a vent issue at your home is all! A clogged drain could be an issue, but is unlikely as per your description here!

Check with local folks... see what they say!

Mark