A grit slurry is introduced through the inlet openings which directs flow down and toward the center of the bin. Grit settles in the settling chamber and once full, the clarified, degritted water at the top overflows a weir and is directed to an effluent connection which can be directed back into the process flow. Grit accumulates at the bottom of the unit burying the stainless steel wedgewire screen. Periodically, the drain valve is opened allowing the free water to drain through the wedgewire screen and the sand bed without releasing captured grit. The bin can then be dumped and a new batch started.