A 50m long fatberg has been removed from a Plymouth sewer in a clean up operation which took over a month to complete.
The fatberg was discovered in December 2020. It was over a metre wide and a metre deep and took four workers from specialist contractors Clear-flow 34 days to clear with over 88 tonnes of debris being removed.
Fatbergs form when waste which cannot be broken down is flushed into sewers. Products such as baby wipes, hygiene wipes, cleansing pads and sanitary items as well as hardened fat and cooking oil congeal to block sewers, causing serious problems for water companies.
The Plymouth fatberg was blocking a sewer leading to the Edinburgh pumping station in Devonport. Whilst the removal was taking place, South West Water had to divert wastewater away from the blockage via temporary overland pipes.
So compacted was the debris in the fatberg that the team had break it up using pickaxes, crowbars and hammers. Larger lumps had to be removed from the sewer via buckets and cranes before being driven away to landfill.
South West Water’s director of wastewater operations, Mark Hillson, revealed that the total cost of clearing the sewer ended up nearing the £100,000 mark.
“It took over a month to remove this monster in exceptionally challenging work conditions,” said Mr Hillson. “We would like to remind all our customers to only flush the 3Ps – pee, paper and poo – down the loo, and to not dispose of cooking fats, oils and greases down the sink.”
Foreign objects being disposed of with wastewater was a particular problem during the first coronavirus lockdown in the spring of 2020.
Toilet roll shortages caused by panic buying saw paper towels, wet wipes, newspapers and other non-biodegradable alternatives being used and then flushed away. Anti-bacterial wipes being for cleaning hands also caused significant issues when flushed down toilets.
More time spent at home led to more home cooking taking place. As a result, increasing levels of food waste, fat and oils were being poured down sinks and into sewers.
Scottish Water reported a sharp increase in the number of blocked sewer pipes they were dealing with. In one fortnight in April, the company had to clear 1343 blockages at an average of nearly 100 a day.
Northumberland Water reported a similar increase in call outs while Severn Trent foresaw the problems to come, issuing warnings to their customers at the start of lockdown about the dangers of treating a toilet like a bin.
The Plymouth fatberg is still some way short of the largest blockage found in a Devon sewer. A 64 metre fatberg was discovered under The Esplanade in Sidmouth in December 2018.
It took eight weeks to remove with 36 tankers worth of debris being taken away. Analysis of the contents of the fatberg carried out by the University of Exeter discovered the usual suspect materials as well as items such as glasses and false teeth.