liquid such as water in a salt dome cavern or other underground cavern the nitrogen 1 is admitted at a pressure of about 20 to 1000 psig and temperature of about 30 u00b0 to 140 u00b0 f through a sparger string 2 passing through a seal 3 brine 4 is passed through a brine string 6 and a seal 7 sparger string 2 extends downwardly into a salt dome cavern 8 having a brine level 9 typically the brine 14 or other liquid is at a temperature of 75 u00b0 to 140 u00b0 f sparger string 2 connects with sparger 10 close to the bottom of cavern 8 and releases bubbles 11 which pass upwardly in the brine out of the cavern via casing 12 and then to atmosphere or recovery via conduit 13 gas bubbles tend to spread and swirl and mix thoroughly with the brine in every part of the cavern when brine is pumped out for degassing as is the case with the invention of u s pat no 3 289 416 cited above a thorough mixing action is not readily obtained and the brine in the remote areas of the cavern can only be thoroughly reached after extensive pumping about 75 of the contaminating gases are removed from a salt dome is one week by the present invention by comparison approximately three months of pumping at normal rates as practiced in the art are required to remove 75 of the gases by a process such as.