Wallender Born Cold Water Geyser

The cold water geyser is also affectionately known as the Brubbel. In order for it to roar so nicely, it needs carbon dioxide gas and water under an impermeable layer like clay. The origin of carbon dioxide is a magma chamber at great depth, from which it rises in crevices and crevices. In the well it slowly enriches the water and the pressure in the well slowly drops. The further the pressure drops, the faster the carbon dioxide bubbles, which cannot dissolve in the water, rise and raise the water level. The excess carbon dioxide then jumps out as a gas-water mixture as a fountain.

The Wallende Born (popularly called Brubbel) is a cold geyser of volcanic origin and in this way unique in Europe. He wets at regular intervals of about 35 minutes and injected up to 4 m in height. The said height is reached at corresponding groundwater level.

"... A seemingly peaceful fountain awakens and begins to bubble. Suddenly a fountain of 9°C cold water shoots into the sky, bubbling up for six minutes. Then the spook is over just as quickly as the "bubbling" like that Locals affectionately call their phenomenon, calms down.
The basis for this natural spectacle is a carbonated spring, one of which there are hundreds in the Eifel. In the early 1930s, Wallenborn wanted to use this industrially and started drilling. But when they tried, chunks of earth and water flew around their ears. They had stumbled upon a chamber in which rising CO2 was collecting and pouring out with force and water to the surface.
The fact that the "Brubbel" still spits out at such regular intervals today can be explained by means of a comparison: Similar to a soda bottle that is shaken, the pressure in the underground chamber increases. At some point – after 35 minutes to be precise – this exceeds the pressure of the water column above it. The Wallende Born was born - the cold water geyser in the Eifel. ..."
eifel.info/a-wallender-born