Collect groundwater near your home’s foundation with the sump box to prevent erosion and costly property damage. Also known as a sump pit, sump tank, or pump vault, the 12 in. Square Sump Box houses the sump pump and is made of high-impact polystyrene (HIPS) treated with UV inhibitors. Fits the 12 in. square sump box cover and riser, sold separately. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects—or we’ll replace it. As part of a complete drainage system, the sump box works with a sump pump system to relieve hydrostatic pressure caused by high groundwater near building foundations. Typically placed at a low point underneath the basement floor, the sump takes in surrounding groundwater and pumps it out and away from your property.