An apparatus for removing particulates from a wastewater stream includes a chamber having a wastewater inlet and wastewater outlet which promotes a generally horizontal wastewater flow. A grating is provided in the chamber between the wastewater inlet and the wastewater outlet having a screen size for preventing the passage of particulates having greater than the select effective diameter from the wastewater inlet into the wastewater outlet. The grating is vertically inclined relative to the direction of the wastewater flow. A baffle within the chamber is configured to cooperate with the grating to generate a vortex in the wastewater having a velocity component parallel to the face of the grating which urges particles trapped by the grating along the grating toward a surface of the wastewater to suspend particles in the wastewater as the wastewater flows between the wastewater inlet and the wastewater outlet.