Apparatus with improved grit removal

A grit removal system with an annular grit removal chamber 22 and a central hopper (24, Fig. 2) beneath the chamber bottom, including an opening through the chamber bottom to the hopper. Influent and effluent channels 60, 80 direct wastewater into and out of the grit removal chamber. A plate 30 over the chamber bottom opening has a first portion (30a, Fig. 4) with a plurality of first openings 34 therethrough and a second portion (30b, Fig. 4) with a plurality of second openings 35 therethrough. The flow velocity for a given flow rate through the first openings is greater than through the second openings. In one aspect, the plate portions are split along a line and the first openings have a size, shape and/or number different than the size, shape or number of the second openings. The wastewater carries grit inwardly toward the plate whereby the flow path for grit passes over the plate so that a majority of grit flowing into the central hopper from the grit removal chamber passes through the first openings. In a further aspect, the area of each of the second openings is greater than the area of each of the first openings.