Grundfos 96971331 SL1.40.A40.100.A.4.61H Wastewater Pump. The SL1 Series Pumps are designed with single-channel impellers, and serve as a powerful and efficient wastewater pump in a handful of functions that include; Inlet pumping stations, wastewater treatment plants, secondary clarification, residential and industrial applications. This Grundfos 96971331 SL1.40.A40.100.A.4.61H Wastewater Pump is loaded with multiple features designed to cut down on energy cost, and improve the overall performance and lifetime of the pump. These features include a body/parts constructed out of cast-iron and stainless steel, heavy-duty ball bearings greased for life, a self-cleaning S-Tube impeller, and a service-friendly design for quick and easy maintenance. This pump is factory tested, and ideal for speed-controlled operation to keep the energy consumption at a minimum. This Pump Model is NOT Explosion Proof.