Our indoor simplex 18" x 30" polyethylene basin with a steel cover is an essential component to the pump system that collects water or wastewater. This type of basin can be used indoors in a residential or light commercial building using a submersible effluent or sewage pump. Zoeller®, 31-0615, Pump Basin, Simplex, 18 in Width, 30 in Height, Polyethylene