Male vs female: We have a great difference of opinion. The wind blows all the time in Oklahoma and we have a sewer smell outside, the area where sewer pipes run and connect to the City line. The ground above this line has depressed considerably in one week, but we have no problems inside the house, except one toilet in the guest house that bubbles when flushed (flushed maybe twice a month). The City hook-up is right outside the property line, where a breeze would carry the odor towards us, but the City ran 400 feet of line in two directions and there was no blockage: they hung a deodorizer inside from the manhole cover. I say the ground is the key; there is a collapse or leak, thus the odor. My husband says the ground is just settling after a drought summer and the odor is from the City line. Any helpful tools or clues to help solve this? I really would like to call a plumber...

Just to clarify. You only smell it outside, or inside or both? Sewer gas smells are one of the hardest problems to locate. However, there are a few things you can do to test. Smoke test, plugging or capping off fixture connections and filling system with water (only good for testing in the home). If you can find a plumber that is very proficient in finding the source of sewer gas smells, I would definatley give them a call. Just know that it may turn into a trial and error type of situation. One step at a time. But first, please answer my first question: smell outside, inside, or both? And, is it stronger in certain areas than others?

Thanks for the reply. It is only outside that we have any smell. It is located in one specific area which happens to be a long run of brick which includes the master bath. The house construction was completed 4 years ago and tree roots are not a factor.

Have you checked for a open cleanout?
To check the outside line I would hire a "Sewer CaM" to go in and taker a look.
But you also have a problem inside your house.

one toilet in the guest house that bubbles when flushed And that bubble is sewer gas entering your house.
You have a partial blockage in the toilets drain line causing a blowback of sewer gas. The solution would be to pull the toilet and snake the drain line.
Good luck, b Tom

Suggestion to try to determine weather the odor is coming from the man hole or the sink hole.
First cover the man hole with plastic and put a little dirt around the edges to seal it. If odor dissipates the odor is coming from man hole.

Then do the same with the sink hole.

What ever the results, the female wins.