I wish to drain my water softener into my septic pipe in the basement .The problem is , there is no laundry in the basement. My question is , can I cut into the PVC septic pipe that runs along the wall , put in a P trap, and have that work correctly? Or is it a must to have this vented ?any help would be great... Mike

I wish to drain my water softener into my septic pipe in the basement .The problem is , there is no laundry in the basement. My question is , can i cut into the PVC septic pipe that runs along the wall , put in a P trap, and have that work correctly? Or is it a must to have this vented ?any help would be great .....Mike
EVERY fixture that has a trap MUST be vented. But before you do that check with the building department. In some areas it's against the law to discharge anything except gray water and sewage into the Public Sewer System. Good luck, Tom

After you check with the city about that water softener discharging into septic.. may also want to ask if they allow AAVs in your area.

An AAV is a Air Admittance Valve that acts as a mechanical vent (spring loaded)... see picture.

If allowed, you would cut a WYE fitting into the pvc septic pipe, install a trap and the AAV.

See the other picture (ignore the sink)... can install like pictured (AAV should be about 6 to 12" above trap)... or can also install on the vertical.

Le us know what you think... Mark

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