What Is a Submersible Sewage Pump with Agitator? A submersible sewage pump with agitator is a heavy-duty pump designed to operate fully submerged in wastewater, sludge, or slurry. Unlike standard sewage pumps, it includes a built-in agitator--a small impeller located at the pump inlet that stirs the fluid and breaks up solid materials before they enter the pump. This innovative feature helps prevent clogging and ensures that solids and sediments remain suspended in the liquid, allowing for smooth and continuous flow through the pump and discharge line.