A system for forming and/or maintaining a fundamentally impervious boundary within a salt cavern for storing very high purity hydrogen is provided. The system includes a salt cavern comprising a salt cavern wall; a conduit configured to introduce a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; the conduit also configured to remove the compressed very high purity hydrogen gas from the salt cavern, wherein the stored very high purity hydrogen gas is maintained at a pressure greater than about 1.0 psi per linear foot of height within the cavern, and less than about 4.0 psi per linear foot of height within the cavern.