Update on sewer gas smell

house traps are still used in many parts of the country, check with your local building/plumbing dept. or sewer authority.

Sounds like you tried everything, but are you shure its comming from your sewer?? Do you smell it everywhere in your house or just in certain rooms?? Does your house have a basement or a crawl space, or are you on a cement slab? If you have a basement has it ever flooded with sewage or ground water, if it has you might be growing something behind your walls if your basement is sheetrocked.Does your house have a sump pump, is the smell comming out of the cover(if it has a cover)? Sometimes a sewer line will break underground and leach into the fill under the concrete and slowly make its way to your sump pit.(A smoke test will not always show a break underground.)Another test you can do is pepermint, if the smell is comming from the sewer you will smell pepermint in your house right away. As for a trap in your main line you will have to check with local codes but my advice to you is not to put one in, you will eventually have trouble with it (plugging up, and then you will have sewage in your basement!!). Another place to look (or smell) is in your drains before the p-traps, the pipes from the top of the drain to the top of the water crown in the p-trap could be your source of smell, a good spot is in your lavatory drain overflow if you puut your nose by the overflow and take a whif and it knocks you on your but you have found your smell. Usually this type of drain will not smell up your whole house but if every bathroom has the same smell I suppose it could get the whole house.Thats about all I can think of right now . Keep us informed on what you found!! Good luck!!!!!!!!