The historical marvel beneath our feet…

It’s time to discuss something that has improved our lives immensely but is not dinner party conversation…..unless you don’t like your hosts?

The sewage system.

‘God displayed a sense of humour when he configured the region between our legs an entertainment complex built around a sewage system’.

Neil deGrasse Tyson

Ooops, not our personal sewage system and sorry that was a totally crass but you have to admit — funny quote. No, I’m actually talking about the sewage system we use multiple times a day. That copes with our rubbish, our bodily discharges and our excess rain water. It is one of the things around us that we take for granted yet it’s development through history is fascinating.

Now we may regard the sewage system as the preserve of the modern but Historians believe that there existed surface drainage systems for storms in the Babylonian and Mesopotamian Empires in Iraq (c4000–2500 BC). Some knowledge of hydraulic water systems in those times also enabled the washing away of faeces. However it took until c3000 BC to develop more formally organised systems operated by people which connected toilets to a sewage system able to swill human faeces and effluent into rivers. Evidence of this invention was found in what is now Pakistan.

In Roman times, a seated latrine was developed and all households were linked to the sewage system to prevent excrement being thrown onto the street (bizarre to imagine people thinking that was acceptable but it was). The Romans sophisticatedly started to separate out the waste water from when they used to bathe communally from other sewage. But it seems that much of the advancements made by the Romans were forgotten as haphazard maintenance meant that as time progressed, only very basic systems were left to be evidenced in much of Europe. Open air defecation became familiar again. Filth and disgusting smells were common place in complete contrast to the beautiful and clever evolution in architecture and art that was concurrently occurring.

So picture a London street as it would have been in those times. Waste gathering on the streets, in people’s cellars — sometimes next to the kitchen — dung, vomit, pee, faeces, garbage, rotting vegetables, animal skins and guts (phys.org). Further to this lovely vision consider that London pre the 1840’s had another serious problem. An outbreak of Cholera killed 6,000 people in 1831. The dominant theory was that it was transmitted through the air though many suspected that it was the water in the city that was contaminated and the true cause. Why was this?

Although the solid parts of excrement and detritus could be collected at dark by night soil collectors and taken into the surrounding gardens around the city, waste water was allowed to flow along the streets, seeping into the ground and flowing directly into the River Thames. This meant for many having clean drinking and washing water was almost impossible as their daily sources of water came from the Thames or shallow wells from around the city. Additionally I was surprised to learn that during this time, even as the poor suffered with limited options, technology was such that the wealthy secured flushing toilets which expelled faeces straight into the river.

In the Summer months particularly, the stench from the river given all that it held — must have been ghastly and unbearable. And we think the Thames is dirty now!

In 1848, the Government established a commission looking into proposals for containing London’s sewage. Joseph Bazalgette, an Engineer by background was appointed Chief Engineer and came up with a plan which began to be implemented from 1858. And why did the politicians decide to do something about it? Well the fact that the Houses of Parliament on sat on the River Thames tells you all you need to know! Can you imagine how overpowering the stink must have been — no wonder they passed a bill to deal with it in 18 days — such was the support. The plan involved creating underground integrated waste pipes collecting effluent from minor sewage pipes and carrying it to places to be stored and then discharged into the Thames when the tide was going out. To move the sewage, the project would make use of gravity and also the biggest steam engines in the world. The strategy entailed the replacement of 165 miles of sewage pipes; the creation of 1100 miles of pipes and the digging up by hand of millions of cubic metres of soil.

This was an incredible feat but the scheme still entailed pouring sludge into the Thames and so in the 1880’s the first treatment of sewage was carried out.

Astonishingly, much of this astounding Victorian endeavour survives in use today. Due to Bazalgette’s foresight the system has been able to cope with the boom in London population. However in recent years, on stormy days, sewers can overflow and flood into the Thames, discharging their contents into our murky river. This is why a 25km super sewer is being built under the Thames (The Thames Tideway project) to prevent waste ever flowing into the river again. Some think upon completion in 2025, this could mark the return of significant wildlife into the Thames. I like to think that could be possible as we have had sightings of Seals and Whales already.

On a more salubrious note, I remember going to visit the largest Fatberg in a local museum. You don’t know what a Fatberg is? You are lucky and I’m sorry to enlighten you. These are essentially balls of wet wipes, cooking oil, condoms and poo which have come from our personal disposals and have congealed together in a sewer. I’m not sure why I felt the need to see it but the largest one that has been discovered in London was 84m wide and weighed the same as 13 elephants. Yes it was as disgusting as it sounds.

On a more positive note, I read an interesting article on how better analysis of our sewage can help us understand and track disease (Covid, Polio) and usage of illegal drugs which can prevail in water and other personal matter. This is called Wastewater mapping. It seems to suggest that through samples and the use of modern day technology it could be quite effective in raising red flags because:

• It is cheaper, easier to implement and handle than analysing people.
• It is surprisingly inclusive — that is, it can test a wide variety of areas and demographics.

In some ways this is nothing new. Epidemiology was spawned in a sewer when in 1854 John Snow a London Doctor plotted Cholera cases on a map and realised as mentioned above that it was not being caused by airborne particles but by contaminated sewage.

I have memories of my childhood visiting relatives in India who lived in small unconnected villages. Going to the toilet entailed carrying a small ‘lotto’ of water and visiting the local field. Such was the non existent underground infrastructure. But more wonderful memories of Monsoon where the local and very basic road gutters couldn’t cope with storm overflow allowing me the street urchin to swim, dive and toss and tumble in the fast flowing rivers that were formed. Exhilarating! Though it is also a sober reminder that even today there are areas of the world where an inadequate sewage system is the norm — holding back progress in many countries.

So when you next use the toilet it’s worth appreciating this quiet marvel of engineering that has not only improved hygiene but our aesthetics and how we smell. I know I do. Which is why it is really irritating when a cost centre somehow manages to miss peeing in the bowl and suddenly this promethean advancement that many have suffered for feels like it’s passed my family by…..grrrrrr…..