My son just moved into a slab house on a septic system. After using the washing machine, they noticed a sewer smell coming from the shower drain. They had showered the day before. If there is indeed no trap between the shower and the septic tank, is there a solution short of a jack hammer? Perhaps a valve? The drain is a trough style with a 1.5 inch opening.
I told him that maybe the washing machine had emptied the trap. There is a vent for the washing machine and behind the shower.
Is there a simple way to tell if there is a trap? Thanks