The large mouth dispenser sump modular design provides versatility and ease of installation. There are six polyethylene bases in three lengths and two depths. These bases have a large 22" wide by 24", 36" or 48" long openings, easing the installation of entry boots and piping connections. The ribbed riser can be cut down in 3" increments in the field to achieve proper pipe slopes with respect to grade. A variety of large mouth tops (LMTs) are available to match nearly every dispenser model. The lids are corrosion-resistant painted steel to which shear valves and dispenser frames are mounted.