A grate cover in combination with a swimming sump being installed in a recess in the top of the sump. The grate cover having a multiple of interstices or openings there through. The size of the interstices being held to a minimum so that fingers of a human cannot be sucked into the openings. The top surface of the grate cover has a curvature thereon while the bottom surface is flat. This way, the forceful suction within the sump cannot obtain enough force to suction the skin of a human against the grate cover to cause any injuries.