Slow drains and odors between pump-outs
A grease trap holds grease; it does not remove it. Between scheduled pump-outs, fats, oils and grease keep coating the line, the baffles and the walls of the trap, and that film is what turns into a slow drain and the sour smell from the floor drain.
Pumping empties the trap. It does not clean every inch of pipe downstream, and a kitchen that cooks heavily can feel the buildup well before the next visit is due.
