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Game-changing sewer tech trial to reduce pollution caused by blockages

Monday 1st February 2021 11:15

Sewer level monitors can help identify sewer blockages early

Sewer level monitors can help identify sewer blockages early

New intelligent sewer technology is being pioneered by Thames Water in Henley-on-Thames in a game-changing drive to prevent pollution from blockages caused by cooking fat and wet wipes.

As a digital leader in the industry, Britain’s biggest water company is trialling the next generation of ‘sewer level monitors’ which send data to help pinpoint emerging problems before they grow into blockages that can cause flooding and pollution.

More than 300 smart devices have just rolled off the production line and are being put to the test in real-world conditions in Henley, and West Ham and Harlesden in London. If successful, there’s then the potential for a bigger trial later in the year.

In 2017 a huge fatberg was found under Hart Street in Henley town centre. The road was closed for several days as Thames Water engineers successfully cleared the blockage.

Backing the trial, Henley town and county councillor Stefan Gawrysiak said: “Anything that will indicate that there’s a blockage or fatberg building up has got to be a good thing. Digging up the road is hugely disruptive to commerce and transport, and from my science background it sounds like an incredibly good, technological, solution.”

The upgraded monitors are fixed under manhole covers and measure the depth of wastewater underneath. Rising water can signal a blockage is forming in the pipe, normally caused by fat poured down the sink or wet wipes flushed down the toilet. Blockages can also be caused by debris and tree roots.

Compared to older monitors, the new devices will help Thames Water build a digital model of the network in the trial zones, giving a much clearer picture of what is happening underground. The older monitors are also much bigger, meaning they don’t fit into all types of pipes.

If levels begin to rise, an alert is triggered at Thames Water’s control centre in Reading so engineers can work out the best plan of action, including sending a team to the scene to clear the blockage before it impacts customers or the environment.

The monitors are another example of the tech Thames Water is embracing in the fight against leaks and pollution. In November, it was recognised as one of the country’s leading digital companies after winning four titles at two prestigious IT industry awards.

Anna Boyles, Thames Water operations manager, said: “We’re industry leaders in harnessing the latest digital tech to find and fix blockages and leaks before they affect customers or the environment.

“These new sewer level monitors are the very latest bits of kit – they’ve only just come onto the market. They have a longer battery life, are smaller and easier to install. The data they provide will give us a much better picture of what's happening in our sewers and will help us to nip blockages in the bud before they cause problems.”

On average, Thames Water spends £18 million every year clearing 75,000 blockages from its sewers, unclogging five house blockages and removing 30 tonnes of material from just one of its sewage works every day.

Anna added: “We get thousands of blockages on our sewers each year that are entirely avoidable. They are caused when things like wet wipes, nappies or cotton buds are flushed down the loo, or when cooking fat from kitchens is poured down the sink.

“Most people don’t realise that wet wipes are nearly entirely plastic – it’s no different to trying to flush a plastic bag down the loo! Even if they say they are ‘flushable’ please, stick them in the bin instead.

“We’d urge everyone to help by only flushing the 3Ps – pee, poo and paper – as well as disposing of fat and oils in the bin, not the sink. It all helps to keep the sewers flowing and to prevent them blocking and backing up into people’s houses and gardens, or even into the local rivers.”