To try and stem the build up... they have a pipe that goes to the bottom of the lake with a dome on the bottom (3-4 ft in diameter)

They pressurized all the water out of the pipe and then "let go" the pressure. This caused the liquefied CO2 to decompress and begin a process that continues to this day.

The GAS *IS* light and travels with great speed towards the surface, in the pipe. It carries CO2 laden water and other gases with it and spews about 70 feet above the water surface from the pipe.

Its not enough to eliminate the build up, but evidently based on some estimate, it should help with the frequency of these massive out-gassing.

There is another lake in Africa that also has Methane build up of same proportions... They are doing a similar thing but using the gas to power Electrical turbines and other items.