A strainer assembly for use with a floor waste receptor having vertical walls and a floor forming a well into which liquid waste material can be collected and directed toward a well discharge opening and then into a drain pipe, the vertical walls having an outer flange extending outward from the vertical walls at a position below the top surface formed by the vertical walls, and an inner ledge formed below the top surface, and the floor shaped to form a ledge around the drain opening, comprising: a well discharge opening strainer assembly; a basket strainer sized to fit in the well and over the well discharge opening strainer assembly and sit on the floor ledge, the basket strainer provided with openings sized to permit liquid water matter of a second predetermined size to move from the floor receptor well through the basket strainer and into the well discharge opening strainer assembly, and a grate strainer sized to sit on the interior ledge.