On August 15, 1984, a limnic eruption occurred at the lake, which resulted in the release of a large amount of carbon dioxide (CO2) that killed 37 people.
Two people sitting on top of the truck survived, because their elevated position allowed them to breathe – carbon dioxide is heavier than air (oxygen and nitrogen) which causes it to stay close to the ground.
Two years later, on 21 August 1986, a similar and much more deadly event occurred at Lake Nyos, about 100 km (62 mi) north-northwest, killing 1,746 people and more than 3,000 livestock.
In March and April 1992 preliminary test were conducted at Lake Monoun using the gas lift method as known in the petroleum industry.
The HDPE plastic is flexible, not brittle, and resistive to chemical and weathering alteration as proven material for natural gas distribution networks.
The pipe could be easily soldered electrically in the field from standard 6 m (20 ft) segments, and deployed with just the help of a few rubber boats plus floats.
[3](p 283) In December 2013, the degassing pipe was upgraded with a small solar-power driven rotary pump, since it had lost its self-lift capability due to the bubbling effect in the riser as a significant amount of CO2 had been removed from the bottom layers.