Puregold Medium Chips are used for sealing shallow boreholes and seismic shot holes, decommissioning wells, and to provide an interface between gravel pack and bentonite or cement grout. They prevent infiltration of surface contamination, and provide a high-solids bentonite seal that is permanent and flexible. Puregold Medium Chips are natural sodium bentonite screened to ¼ to 3/8 inches in size. They are NSF/ANSI Standard 60 certified. www.cetco.com/dpg