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The Incredible Story of London Sewers


Very few people have made such live-enhancing advancements to the way of life as the mastermind of today’s Megaproject. His construction revolutionised sanitation and health for Victorian Londoners, and over one hundred and fifty years later is still saving lives every day against the relentless mass of waste that London produces. In fact we could go as far as to say that this man saved more Victorian lives than any other person of the time. Despite this, Joseph Bazalgette remains something of an unsung hero, and should receive just as much if not more recognition as other great sanitary reformers of the nineteenth century. Most of his work lies directly beneath the feet of the everyday Londoner, and although rarely seen the sewer system is one of the most crucial parts of London’s infrastructure.

The very reason the sewer system was built at that time was more of a political decision rather than a life-saving one, and was down to one major problem that affected everyone regardless of class or social status: the smell. If you lived or worked in the city of London at the time then it will have been inescapable, and it was only when those in the highest of power became affected themselves that action was finally taken on how to solve the problem. In order to understand the sheer magnitude of the task ahead, we need to understand the state of London’s sanitation at the time, and before that.

So let’s get a little dirty with the fascinating, if not rather disgusting life of the London sewers.

Waste Not, Want Not

By the 1800’s London had become the largest city in the world, thanks mostly to the success of industrialisation and the mass migration of people that now filled its streets. Of course with lots of people came lots of waste, and with lots of waste came the problem of how to dispose of it. The existing municipal drains were only built to cope with rainwater and night-soil collectors couldn’t empty the two hundred thousand cesspits quickly enough, so over time London became caked in filth. The cesspits themselves were expensive to empty and maintain, so it’s believed they were designed to leak liquid either straight into the earth or as Londoners were now discovering, straight into the streets themselves. If the cesspits weren’t leaking then they were overflowing, often draining straight into the city’s water supply along with a whole host of industrial and general waste. The Thames is of course a tidal river, so instead of the waste heading out to sea it simply sloshed around with the tides and slowly polluted the water and air.

Naturally diseases such as typhoid and dysentery began to sweep the capital and by 1831 London suffered its first outbreak of the deadly cholera, where nearly seven thousand people would fall victim to the disease. The outbreak was taken so seriously that the government opened an enquiry into the city’s sanitation and despite the calls for improvement the government always claimed they simply didn’t have the money for a project of this magnitude. However, with almost two and a half million people now crammed into the city, and a great deal of those living in squalor, the problem of waste contaminating both the streets and the River Thames continued until inevitably in 1848, a staggering fourteen thousand Londoners were lost to yet another cholera outbreak.

1848 also marked the same year that the United Kingdom passed the Public Health Act, a legal landmark in which the government now took responsibility of public health and allowed local authorities to generate large amounts of money to improve sanitation conditions. However, as it often does, red tape proved to stand in the way, and very little was done by those local authorities and the Public Health Act didn’t even apply in London itself where The Metropolitan Commission of Sewers created their own City Sewers Act. They were presented with dozens of proposed plans on how to solve the crisis, but none of them were authorised and the problem continued. Things only got worse after the abolishment of cesspits and the introduction of flush toilets which channelled the flow of sewage directly into the Thames, and with a now unmanageable amount of waste the city fell to a third Cholera outbreak in 1853 which claimed another ten thousand lives.

Part of the problem was the Victorian beliefs on how disease was spread. The ‘Miasma Theory’, in which diseases are spread through bad air, had generally been accepted by most scientists at the time. But there’s always one, and physician John Snow introduced the idea that the recent waves of diseases were spread through contaminated water. He reasoned that cholera could not be spread by bad air as the initial symptoms related to the gastrointestinal tract, when in fact if it was the air then surely it should cause pulmonary symptoms. His extensive research proved of course to be completely correct and yet was widely rejected by the scientific community at the time. Sadly he passed away before his theories were proven to be true, the very year that things came to a head and London could take no more.

The Great Stink

By 1858 the smell now emanating from the capital was overpowering. A relentless heat wave that summer caused the Thames to fall and the human and industrial waste that lined the banks of the river began to cook under the baking sun and searing heat. At first, the lawmakers of the land simply ignored it, never agreeing on action or reform of the overhauling of infrastructure that was needed to fix the problem. Eventually, and unsurprisingly, those in power began to suffer. The Houses of Parliament were becoming unbearable, with parts of the building uninhabitable and politicians having curtains soaked in chloride of lime in an attempt to keep the foul stench at bay. Parliament discussed uprooting the whole of government to outside of Westminster despite the fact that they had only recently purchased the plush new premises overlooking the Thames.

Pressure mounted further after a letter was published in the Times by perhaps the world’s most famous scientist of the time, chemist and physicist Michael Faraday of the Royal Institution, who wrote about the state of the Thames and the pollution that was now dominating its depths. During a boat ride, Faraday threw pieces of white paper into the river only to watch in horror as they disappeared immediately under the surface, proving how dark and dirty the water had become. His letter caught the public’s attention, and the public turned to the government demanding a solution.

Eventually between the outcry and the stench, Parliament could take no more, and a bill was rushed through in a record breaking eighteen days that provided the city with the finances to refurbish the river Thames and build a brand new sewer system. ‘The Great Stink’ as it was to become known, was a defining moment in the history of London, despite various outbreaks of a whole host of deadly diseases, tens of thousands of deaths, frustrated calls for sanitation improvements, and even evidence that contaminated water was responsible for cholera, it was finally the smell that shamed the politicians into action.

The Man with the Plan

Sir Joseph William Bazalgette

And so, in steps Joseph Bazalgette who was specifically hired to take the reins of this undertaking.

The Victorian engineer of French descent became a member of the Institution of Civil Engineers in 1846 and by 1849 he was appointed to the Metropolitan Commission of Sewers for London where he frustratingly failed to persuade the powers that be to back his various plans for an overhaul of the now terribly dated sanitation system. Eventually a much more powerful body was established and Bazalgette was promoted to chief engineer for the Metropolitan Board of Works and was in this position when the Great Stink occurred, only now he had more power to assert the changes he had pushed so many times for.

Bazalgette reviewed over a hundred different proposals in order to come up with the ideal solution for a sewer system that could serve the whole capital. His system would channel waste water and sewage through his underground tunnel network into the main intercepting sewers. He opted for egg-shape tunnels which were narrower at the bottom, this was to not only strengthen the tunnels but keep the system flowing even at times of relatively low water. Thanks to Bazalgette’s gradient of two feet per mile, gravity sent the waste eastwards and dumped it into the Thames at a point where it would be swept out to sea as opposed to back towards the city. Bazalgette had also designed the sewers to cope with the combined waste and rainwater, his argument being that in order to build a separate rainwater system he would then need to dig up London all over again immediately after the sewers were complete. Not surprisingly the combined sewer system was authorised and Bazalgette’s plans started to come together.

The project would create over a thousand miles of street drains and eighty two miles of main sewers that would pump waste under Londoner’s feet into a series of main intercepting sewers with the help of four pumping stations. These pumping stations were a testament to the architecture of the Victorian age, as grand as they were extravagant the stations have become renowned for their beauty, with Crossness in particular being described as a “Cathedral on the marsh”, a nod to its gothic splendour. Alongside this Crossness also had the accolade of housing the largest steam engines in the world at that time. Bazalgette would also build the Victoria, Albert and Chelsea embankments that would not only encase the new sewer pipes but also narrow the river and strengthen the overall flow which would help keep the Thames considerably cleaner than it had been in the years before

Bazalgette chose to use the relatively new Portland cement in order to hold together the three hundred million plus bricks that would be used to make the new sewer system. This choice was somewhat controversial at the time as Portland cement had to be mixed correctly for it to do its job to the fullest. Confident in his choices, Bazalgette insisted the Portland cement was far superior to the previously used Roman cement and would have more durability and strength when submerged by water. The bricklaying was an integral part of the process and had to be done accurately. It is believed that demand was so high for workers, that bricklayers wages increased by twenty percent making it a very profitable job during the years of construction.

The success of the project can be attributed to Joseph Bazalgette’s obsessive work ethic, overseeing every detail of work with impeccable attention and leaving nothing to chance. His Draconian quality control system was second to none, inspecting every plan that was passed and visiting the various sites to check if the work was up to his required high standard. He built the sewers to withstand extreme weather events and created solutions for possible future problems that might arise by calculating the size of the sewers needed for anticipated flow rates at the time, and doubling it, creating a system capable of coping with the waste of around four million people. The foresight behind this was simple; the system will be built once, and should be built to cope with the waste of the growing city. The long and complex construction of Bazalgette’s London Sewer system ended up at the cost of just over four million pounds, equal to about five hundred million today.

HRH the Prince of Wales officially launched the brand new system from the Crossness pumping station on April 4th 1865 just seven years after the Great Stink.

Saving Lives for Generations

The true value of Bazalgette’s system was realised in 1866 when a new cholera outbreak swept the land. London remained relatively unscathed with only those in the East End of the city falling victim to the fresh onslaught of disease. The reason behind this is simply down to the fact that the East End was not yet connected to Bazalgette’s system, leaving their water supply vulnerable to contamination.

And so as the years rolled by, the new sewers performed exactly as Bazalgette had designed and provided a safer water supply, improving the quality of life more than anyone else at the time. We can only imagine the further outbreaks of diseases that could have continued to ravage the London population which was now growing at incredible levels.

For his innovation in sanitation Bazalgette was awarded the highest accolade in the land; a Knighthood. By the time of Bazalgette’s death in 1891, the population had doubled to around five million, and yet his system still coped with the capacity of waste and water flowing through its tunnels. The tunnels were in fact so well built that surveys a century later showed no need for repair as the construction was holding up rather nicely. Had Bazalgette not doubled the calculation of the tunnels then London’s sewer system would have failed to cope somewhere around the 1960’s, causing serious overflowing and pollution to plague the city once again.

Over time Joseph Bazalgette has finally begun to receive the much needed credit he deserves, with a memorial dedicated to him located at the Victoria embankment and several written works on the man in question and the legacy his pioneering creation has left. Although his most famous of works isn’t on the map and most Londoner’s will never see it with their own eyes, you can see the mark of Joseph Bazalgette all around the city. He was instrumental not only in the sewer system but also in creating or re-planning major roads in London, leading the design of the Woolwich Ferry which would provide a free service linking Woolwich and North Woolwich, building key bridges including Putney, Hammersmith and Battersea, and was even lead designer on the proposal for what would eventually become Tower Bridge. Bazalgette’s fingerprints are all over London, his creations transforming the capital and remaining significant in the way London works to this very day.

Bazalgette and Beyond

Even the greatest of innovations must eventually fall behind the times somewhat, and with a population heading towards nine million, Bazalgette’s system is in need of an upgrade. As much as its legacy is a testament to both Bazalgette and Victorian ingenuity, the proverbial cracks are beginning to show. With the population beyond the original shelf life of the sewers the overflowing of waste into the Thames is becoming more frequent and causing a major pollution problem once again.

Modern times bring modern problems, so along with the usual array of waste we now have baby wipes, sanitary products, condoms and many more items that pose a constant threat to the now temperamental sewer system. One unexpected blockage that no foresight could have seen is the ‘Fatberg’. These masses of grease, oil and general disposables that don’t actually dispose have become a real threat to the flow of the sewers. A London bus-sized example was discovered in 2013 under Kingston upon Thames, and a few years later a record-breaking fatberg was discovered in the infamous area of Whitechapel. At 250 meters long it stretched further than Tower Bridge, and weighed in at a colossal 130 tonnes, almost ten times the size of the Kingston fatberg. These are just some of the ways waste has evolved since the time of Bazalgette, and in order to combat these changes a modern solution is needed.

To keep the waste flowing, a new super-sewer is under construction that will take what Bazalgette created and bring it into the 21st century and beyond, and just like Bazalgette’s the new system is set to last for at least a century, providing Londoner’s with safer, cleaner water for generations to come.

The Thames Tideway will be a sixteen mile new tunnel that will link Acton in the west of the city to the Beckton Sewage Treatment Works in the east with the aim being to intercept, store and transfer untreated sewage; ensuring waste is channelled away from the Thames River. Planning was approved in 2014, with work beginning in 2016, and much like their Victorian counterparts the engineers of today are experiencing the challenges of building such an intricate construction in the middle of a major metropolitan area with completion finally expected around 2025.

Much like Bazalgette all those years ago the new building works also involve creating new areas of public land, with seven new locations taking up three acres of London that will give the city even more access to the Thames, creating green spaces and social hotspots for Londoner’s to enjoy while overlooking what should be the cleanest Thames River in a very long time with around 94% of the sewage currently entering the Thames on a yearly basis being intercepted by the new super sewer.

The company behind this massive task, fittingly named Bazalgette Tunnel Ltd, have a lot to live up to. They take their name from the very man that transformed the life of the city by providing safer water for all. Bazalgette eradicated cholera amongst a whole range of other waterborne germs that could no longer thrive in the city streets, so although it’s impossible to predict exactly how many lives he has saved over the years we cannot ignore his contribution to the health and shape of London then, and ever since.

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