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LONDON: The rattling door of the steel box lift closed and a crane slowly lowered the masons building London’s “super sewers” 40 meters (130 feet) to the bottom of a massive vertical shaft.
Here, far from the busy city streets, thousands of engineers and construction personnel have spent the past seven years creating the largest-ever upgrade to the city’s sewers in the 19th century.
The current London sewer system dates back to the second half of the 19th century when it was designed by civil engineer Joseph Bazalgetti in response to the infamous ‘stench’.
In July and August 1858, a combination of high temperatures and a sewage system emptied directly into the Thames engulfed the town in a cloud of putrid air.
The unbearable stench created a sewage system that is still in use today.
But in recent decades, a lack of capacity due to the population growth of the British capital has caused raw sewage to flow back into the river.
Although a 19th-century engineering marvel, Bazalgette’s network used the same pipes to carry sewage and rainwater, resulting in effluents often flowing into the Thames for lack of capacity.
“Anytime it rains, even if it’s light rain, the sewers fill up and pour directly into the river,” said Taylor Gill of the Tideway company behind the project.
“Currently, on average, 40 million tonnes of sewage seeps into the Thames without ever being treated,” he said.
Although the old brick-lined sewers – built between 1859 and 1875 – are still in “rudimentary condition”, they are not large enough.
“The issue is capacity,” Gill added.
The network was created when London had a population of just four million compared to about nine million today.
As the population continues to swell, the need for a £4.3 billion ($5.6 billion) upgrade is paramount.
The new 25-kilometer (15-mile) long, 7.2-meter-diameter sinkhole snakes west to east following the curves of the river.
When running, it will only carry sewage when rain means existing sewers are full to overflowing.
The overflow points would allow sewage that would have flowed into the Thames to be diverted into the new tunnel.
At its height, 10,000 people were working on the project, which saw the formation of six tunnel boring machines through three distinct geographies – clay in the west of the city, sand and gravel in the middle and chalk in the east.
However, the final stages of the mega project come amid controversy over the privatized water sector, which has been accused of chronic underinvestment in its networks.
Latest figures from the government-sponsored Environment Agency show there were 825 sewage spills per day on average last year in UK rivers and coastal areas.
A number of beaches on the Isle of Wight off the south coast of England were closed during last year’s summer heatwave due to a rise in bacteria from polluting the water.
Surfers Against Sewage, a lobbying group, recently published a list of 83 beaches to avoid in Britain for their raw sewage discharge.
The government confirmed this week that water companies, as well as others such as energy and waste operators, will face unlimited fines for polluting practices.
The boss of Thames Water, whose customers finance the tunnel through a tax on their bills, resigned in late June amid an uproar over the company’s £14bn debt.
With the tunneling phase of the “super sewer” completed last year, it is on track to be piloted in 2024 and fully operational by 2025.
“What we do is intercept and remove 95 percent of spills,” Gill said.
“So once we’re done, the river won’t look much different—it will always be quite a muddy river—but it will be a much healthier environment for the fish, marine mammals, and birds that live in it as well as for the paddling communities that use it.”
Matthew Frith of the London Wildlife Trust agreed that the new sewers would make a “significant contribution” to the recovery of the Thames, but warned that it would not solve the problem elsewhere.
“Some (water companies) are taking their responsibilities very innovatively. But whether there is that level of investment that we have in London, I’m not sure that’s the case yet,” he said.
Here, far from the busy city streets, thousands of engineers and construction personnel have spent the past seven years creating the largest-ever upgrade to the city’s sewers in the 19th century.
The current London sewer system dates back to the second half of the 19th century when it was designed by civil engineer Joseph Bazalgetti in response to the infamous ‘stench’.
In July and August 1858, a combination of high temperatures and a sewage system emptied directly into the Thames engulfed the town in a cloud of putrid air.
The unbearable stench created a sewage system that is still in use today.
But in recent decades, a lack of capacity due to the population growth of the British capital has caused raw sewage to flow back into the river.
Although a 19th-century engineering marvel, Bazalgette’s network used the same pipes to carry sewage and rainwater, resulting in effluents often flowing into the Thames for lack of capacity.
“Anytime it rains, even if it’s light rain, the sewers fill up and pour directly into the river,” said Taylor Gill of the Tideway company behind the project.
“Currently, on average, 40 million tonnes of sewage seeps into the Thames without ever being treated,” he said.
Although the old brick-lined sewers – built between 1859 and 1875 – are still in “rudimentary condition”, they are not large enough.
“The issue is capacity,” Gill added.
The network was created when London had a population of just four million compared to about nine million today.
As the population continues to swell, the need for a £4.3 billion ($5.6 billion) upgrade is paramount.
The new 25-kilometer (15-mile) long, 7.2-meter-diameter sinkhole snakes west to east following the curves of the river.
When running, it will only carry sewage when rain means existing sewers are full to overflowing.
The overflow points would allow sewage that would have flowed into the Thames to be diverted into the new tunnel.
At its height, 10,000 people were working on the project, which saw the formation of six tunnel boring machines through three distinct geographies – clay in the west of the city, sand and gravel in the middle and chalk in the east.
However, the final stages of the mega project come amid controversy over the privatized water sector, which has been accused of chronic underinvestment in its networks.
Latest figures from the government-sponsored Environment Agency show there were 825 sewage spills per day on average last year in UK rivers and coastal areas.
A number of beaches on the Isle of Wight off the south coast of England were closed during last year’s summer heatwave due to a rise in bacteria from polluting the water.
Surfers Against Sewage, a lobbying group, recently published a list of 83 beaches to avoid in Britain for their raw sewage discharge.
The government confirmed this week that water companies, as well as others such as energy and waste operators, will face unlimited fines for polluting practices.
The boss of Thames Water, whose customers finance the tunnel through a tax on their bills, resigned in late June amid an uproar over the company’s £14bn debt.
With the tunneling phase of the “super sewer” completed last year, it is on track to be piloted in 2024 and fully operational by 2025.
“What we do is intercept and remove 95 percent of spills,” Gill said.
“So once we’re done, the river won’t look much different—it will always be quite a muddy river—but it will be a much healthier environment for the fish, marine mammals, and birds that live in it as well as for the paddling communities that use it.”
Matthew Frith of the London Wildlife Trust agreed that the new sewers would make a “significant contribution” to the recovery of the Thames, but warned that it would not solve the problem elsewhere.
“Some (water companies) are taking their responsibilities very innovatively. But whether there is that level of investment that we have in London, I’m not sure that’s the case yet,” he said.
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