The removal of a 210ft (64m) “monster” fatberg which is blocking a sewer below a seaside town is set to begin.
The congealed mass of fat, oil, wet wipes and other rubbish was discovered in the sewers of Sidmouth in December.
South West Water has taken 3D scans of the “unwanted Christmas present”, and will begin tackling the removal later.
It is estimated it could take eight weeks to remove the fatberg by breaking it down with manual labour and sucking it up on to the surface.
The clearance teams, who will use a mixture of pick-axes and high-pressure jets, will start work on Wednesday.
They will be wearing full breathing apparatus and body suits because of the dangerous gases released by the fatberg.
High levels of hydrogen sulphate and methane mean the air is also too unstable to risk bringing cameras down to film the removal, according to the water provider.
It is an unpleasant job for the teams involved, with workers from the Whitechapel fatberg in London in 2017 describing the smell as “rotting meat mixed with the odour of a smelly toilet”.
Once broken down into a manageable consistency, the fat will be sucked up a pipe into tankers waiting on the surface.
The fat will then be processed at a plant which turns waste into electricity.
Fatbergs can be prevented by only putting the “three Ps” down your toilet – pee, poo and paper.
Most campaigns by water companies reference the “three Ps” and urge people not to dispose of nappies, condoms and wet wipes this way.
South West Water asked everyone not to “pour fats, oil or grease down the drain, or flush wet-wipes down the loo”.