I do a lot of foreclosures and I find traps dried out all the time, the question is why do I not smell sewer gas in the homes?

Methane gas is odorless., it is other gas mixed with it that usually smells

Hi Bob, It is possible the high vent is taking away the gasses. Also if you do not run water you may not disturb the equilibrium. Once you start running water the trap fills anyway. I know that if we open the septic tank for inspection and there are dry traps inside the house that will sometimes change the equilibrium and cause odors in the house.

Yest that make sense but there would always be the other gasses that smell so my thoughts are most likely nothing is being vented through the traps.

That makes sense!