Every single time it rains, we get a horrible sewage smell all over the inside of our house. It is utterly disgusting. For background information, we have had our sewer lines checked under the house and they are fine, things flush and drain fine, and I generally can't tell that anything is wrong inside our house. We live on a downward sloping hillside with neighbors on both sides. The neighbors up the hill from me have a huge blackish/dark green spot in their yard, year round. I think it is a messed up septic tank issue. Could the mess from their septic system be draining under my house when it rains and cause this smell? If it is possible, what recourse do we have as neighbors and home owners? PLEASE HELP!!

If you are on the downward end, then I would not only have septic checked, but if you are on well water, I would have that checked as well !

It could be their septic tank but it is also likely their sewer gas which exits via the roof. Rainy days makes the gas heavy enough to drop down to the ground. For that matter it could be your sewer gas too.

It only happens when it rains? Or does it happen other times too? Im not sure what to say here without being there to see it for myself. But please do let us know what you find. You may be able to call in a sanitarian to see if neighbors septic is at fault. If you are on good terms with your neighbor, I would suggest letting them know what is happening and let them know that you would like to have area checked.

More info: I do not have well water, we have city water, so hopefully no worries there.

I am a bit of a novice at this home ownership ordeal, but I am wondering about the sewer gas that escapes through the roof. Can anyone give me more information about that? :confused:

House sewer systems need a vent to allow all drains and traps to work properly. Without a vent the sewer water wouls siphon all the water out of the traps and that is what keeps sewer gas from being inside your home. The vent stack is a 2" to 4" pipe sticking up through your roof, it is open to all sewer drain pipes below. When you flush/drain a fixture air is sucked inisde the vent from the roof. The rest of the time sewer gas rises in this vent stack and enters the outside surrounding air, unusally unnoticed.

Yes, your neighbor's neglected septic system could drain under your house. It is creating health hazard issue. You can talk to your neighbor first. If he doesn't correct the situation in timely manner than call local Health Department.