With a rattle, the sliding doors of the makeshift elevator close, and we start tracking the wall of the largest vertical shaft I’ve ever seen.
A concrete tank 60 meters deep and 18 meters wide descending to a junction of tunnels below it, its epic scale resembles something I’ve only seen in a movie: Dune or Bond.
The reality is less colorful. It will fill with what we rinse.
Sky News has been given rare access to the ‘super channel’ or Thames Tideway as it is officially known.
It has three of these giant tanks along its nearly 20 miles of tunnel, each wide enough to accommodate three double-decker buses side by side.
The total construction time will be nine years and the cost will be around £4 billion: an expensive solution to a huge problem.
On average, 39 million cubic meters of sewage-polluted water enters the Thames every year.
LondonThe Victorian sewers were built after the great stench of 1858, the stench from the river so bad that Parliament could not sit.
They were engineering marvels of their time, but more than 100 years later, the thoughtful design decision became a major flaw.
The foul-smelling water from our homes flows through the same pipes that carry rainwater from roads and roofs. So downpours can overwhelm the system – especially as London has grown.
We have more people flushing toilets and more of these hard surfaces of tile and asphalt. To prevent sewage from flowing back into homes, it is intentionally dumped into the river.
Lucy Webster, Thames Tideway’s foreign affairs director, told Sky News: “When they were designed it would have been a very, very rare occurrence.
“But today, with all the development, with the population growing, it’s a very regular occurrence. And almost always when there is rain of any degree in London, it will overflow directly into the Thames.”
Anger over “blooming brown plumes”
The super channel will catch these overflows and send the wastewater to a treatment plant in Beckton, east London, where it will fill these huge tunnels during a heavy downpour. It’s like a new river network outside London.
It costs each London household £18 a year to pay for these costs – but polluted rivers and coasts are a national problem and if it is to be tackled the bill will only get bigger.
The campaign group Surfers Against Sewage recorded 14,000 untreated spills and 700 cases of human illness from sewage last year.
The billowing brown plumes in the rivers and around our shores have caused widespread and political outrage.
This week, the government announced plans to make it easier to punish water companies for sewage leaks, with many activists saying they should find money to clean up from their profits.
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But Alastair Chisholm, director of policy at the Chartered Institute of Water and Environmental Management, says no one is realistic about the scale and cost of labor across the country.
“Right now it looks like a car accident. We have activists who challenge the government. We have the government and other politicians screaming from the rooftops that they really want to punish the water companies.
“We have water companies that have to invest amounts that are potentially unavailable to customers. You will have to really come to terms with reality. And I think that will happen in the next 12 months.”
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The price for removing sewage from our natural waterways is high, but nature pays the price for doing nothing.
Chris Coode of the healthy river pressure group Thames 21 has witnessed the effects of large spills.
“You have a large sewage patch in the river, and as the bacteria break down the organic matter, they use up the oxygen,” he explains.
“So you’ll end up with huge areas of deoxygenated water. Fish can’t breathe, so sometimes you’ll see them on the edge panting. And you can have thousands of dead fish.”