I have a bathtub/shower drain 1 1/2" PVC that goes directly into the main vent/drain (about 8' from the trap) thence to septic tank. I also have the kitchen sink drain 1 1/2" PVC that goes directly to the septic tank (about 25') (this one has a vent near the sink). Question is this:

Can I connect the bathtub/shower drain to the kitchen sink drain? The connection would be approximately 22' from the kitchen vent. The reason for the modification to to get rid of one a portion of the bathtub/shower drain pipe that basically parrallels the kithcen sink drain pipe.

Thanks.

Hey John...

It is never a good idea to connect a kitchen sink drain pipe together with a flat bottom tub/shower unit... especially if the pipes are only 1.5"

Sounds like the tub in unvented as well... yes? If this is the case, be clear that even if you did connect the drain lines together the tub would not benefit from the kitchen sink vent... simply too far away.

Let me know more here... ok?

MARK

I am going to seek some professional advice. Not sure if the tub/shower is revented or not.