Sewage pumps and effluent pumps are used to transfer sewage (wastewater containing solids) and gray water (household wastewater from a sink or bath) into a septic or sewage system. Sewage ejector pumps allow sewage to be pumped from drains that are below the main sewer line to either septic systems or low-pressure sewage systems. Sewage grinder pumps grind down large debris into small pieces so the water can be transferred to high-pressure sewage systems through a small diameter pipe. Effluent pumps have high heads (the height a pump can lift water before there is no more flow) and pressure to push treated gray water out to a faraway drain field.