Monolithic Dome Frac Sand Storage now at State-of-the-Science Facility On its 1,000 acre operation in Voca, Texas, Cadre has three Monolithic Domes for storing frac-sand. For retrieving the sand, each dome has a Monolithic concrete tunnel 23’ wide, 13’ high and about 130’ long. Each Monolithic Dome stores thousands of tons of frac-sand. Note the huge conveyors, resting on the domes, that carry the sand. This is a very special storage system for a very special product: frac-sand.