Bentonite pellets are compressed tablets made from highly swelling sodium Bentonite and when placed forms a flexible, Non-toxic impermeable seal. It will swell approximately 10-15 times their dry state when hydrated with fresh water. Seal or grout plastic or steel casing. Isolate screen intervals, subsurface instrumentation, and sampling zones. Provide a protective interface between gravel pack and cement grout. Plug abandoned earthen boreholes and cavities. Create a stable, permanent below-grade seal in. Monitor/observation wells. Dewatering holes. Caisson holes. Soil sampling holes. Mineral exploration holes. â?¢ Water wells.