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105 tonne ‘concreteberg’ blocks London sewer

A record-breaking ‘concreteberg’ weighing around 105 tonnes has blocked a Victorian sewer in Islington, London.

Thames Water is preparing to extract the solid mass – the biggest the company has even seen. The operation will last at least 2 months and is expected to cause notable traffic disruption.

The blockage, caused by people pouring concrete into the sewers, is believed to be over 100 metres long and weigh the same as a blue whale.

Thames Water will manage sewer flooding risks to properties and the environment by ensuring tankers are available to pump out waste 24 hours a day.

The water company has said it could cost “at least several hundred thousand pounds” to clear requiring a range of cutting tools, including jackhammer pneumatic drills and high-pressure jets.

Thames Water, said it currently spends around £18 million every year to clear blockages from its sewers.

Operations Manager Alex Saunders added: “Normally blockages are caused by fat, oil and wet wipes building up in the sewer but unfortunately in this case it’s rock hard concrete. It’s in there and set to the Victorian brickwork, so we need to chip away at it to get it removed.

“This is not the first time damage has been caused by people pouring concrete into our sewers but it’s certainly the worst we’ve seen. It’s very frustrating and takes a great amount of time and effort to resolve. We’re now doing everything we can to deal with it as quickly as possible, making sure our customers don’t have to suffer because of this mindless abuse of our network.”

The water company has committed to increase monitoring of its network as part of its business plan for 2020/25 using up to 200,000 new sewer depth digital monitors and proposed to reduce pollution by 30%


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