Macerating/dumping into septic system vent stack.

I would first want to make sure I knew where the vent pipe was coming from. In advanced systems, the recirculating sand filter bed is vented. Don't want to dump it there. As far as I know,a normal septic tank isn't vented. But if your vent accesses the first chamber of the septic tank, I would put a "y" on the vent just below grade and create a clean out at grade. I am not a fan of macerating prior to entering a leachfield.