Have a sewer smell in bathtub drain not plugged or leaks?

Question

just hooked up too city water and sewer was on septic tank previosly smell was only there before if the lid was off the septic but i cant any leaks or plugs all pipes were backfilled by contractors with a city inspector verification any ideas are greatly appreciated

Answer 1

Your problem is your vent pipe. The vent pipe runs either up the outside of the house (wall) or it runs up though the roof . In  either case the pipe is either cloged or needs to by raise up a little higher, All you need to do is get a ladder  so you can get to the top of the vent pipe and just run your water hose down into it,  you can turn the hose on it will just run back into your bathtub

Answer 2

Check that the p-trap has water in it.  This is what keeps the methane gas from entering your home.  Just run some water in the tub to do this.  Also check that the vent extends above the roof, and that no other openings have been left uncapped.