I like to watch TV programmes where I learn something, and on Sunday night I watched a very interesting programme. The subject matter is something that we don’t really want to think about, but after watching the Thames Tideway programme, now I can’t stop thinking about it…
In the late 1800s, Mr Bazalgette designed miles of brick-built sewers, all laid by hand, to run under London to cure it of the ‘Big Stink’ problem that was causing MPs of the day to hold their noses in the Houses of Parliament. These Victorian tunnels are now struggling to cope with the effluent from an extra 7 million people, causing much untreated waste to be poured into the Thames via many sewer overflows (about 39 tonnes of it each year!), some of the waste it appears that walkers/ dog-walkers are treading in when the tide is out. Huge fatbergs are clogging up the sewers, along with non-biodegradable wet wipes and other things I don’t want to dwell too long upon. In effect, Londoners are now in danger of reproducing the ‘Big Stink’ problem that was so prevalent in the 1850s.
Thames Tideway has come to the rescue with a giant 25km tunnel running underneath even the underground tube tunnels, which will take up the waste from 34 of the most polluting overflow pipes and stop it pouring into the river. Work started in 2014 and will not be finished until 2023. On the programme we saw piledriving machines at work to build the deep shaft where the tunnelling machine will be lowered down into. It was all fascinating stuff, this heavy industry. Once the cutting machine started to dig out the London clay, it hit more solid limestone, causing hundreds of thousands of pounds to be paid out even at the start, to keep on replacing worn out cutting teeth.
I felt sorry for the lady living nearby in her dream flat, which had turned into a nightmare due to the noise of the piledrivers. Thames Tideway had even paid for her to have holidays to get away from the noise and had also paid for triple glazing her windows, but she was so stressed by the constant noise that eventually she moved out.
This new tunnel is set to last about 120 years. But will Londoners be more careful about what they flush down their sinks and toilets? The answer to that is probably no, because I suspect the majority will not think about the cumulative effect of years of hot fat and wet wipes etc on sewer pipes. It’s up to the manufacturers of wet wipes to design a biodegradable version, and for recycling centres to allow the public and restaurateurs to dispose of cooking fat properly instead of pouring it down the sink.
One day in the not-to-distant future, people might be able to swim in the Thames without getting ill with gastrointestinal problems caused by the ever-present effluent’s bacteria, or getting hit by a floating fatberg!