A Brief History of Sewage

By Mike Smith

I had a real life outside of the classroom before joining the teaching profession. My first few jobs were with various water utility companies in the U.K., largely dealing with river pollution and wastewater treatment. I always had an interest in science history, and I’ve often thought there’s very little as interesting or vitally important as the relationship between humans and the water around us (or that goes through us). Here is my brief history of the subject.

It is popularly believed that the Romans invented the sewerage system; however, there is evidence of indoor plumbing in Mesopotamia 8000BC, used to carry waste to nearby rivers. Flush toilets are known to have existed in 3000BC in Ancient Crete, complete with overhead cisterns. Similar toilets were well established by Roman times. I myself have sat on a stone toilet which was once fed by a river water flush system at Housesteads Fort on Hadrian’s Wall.

One of the most visible effects of the fall of the Roman Empire and the beginning of the Middle Ages was the loss of public sanitation. One exception was castles where there was an obvious need to get rid of noxious waste, particularly in times of siege. There is evidence in England of raised platforms over the moat (presumably with protection from attacking hoards) where one could relieve oneself. This would have given the enemy an added disincentive to ford the moat I presume.

Both before and after the fall of the Roman Empire, waste was commonly thrown into the streets, often from overhead windows. As a result, Roman streets had raised stepping stones to prevent pedestrian citizens from soiling their sandals and togas. The habit of emptying one’s chamber pot onto the heads of passing neighbours led to the Dejecti Efflusive Act of Rome, which allowed a Roman citizen to collect damages after being hit by such ejecta. It became polite for a gentleman to walk on the outside of a lady when walking down the street. In this way, he would be in the line of fire from above. It is often postulated that this practice started to protect ladies from being splashed by the wheels of passing carriages, but the truth is a little more unsavoury.

In Europe up until the 1500s, people were fairly careless and uncouth about where they deposited their bodily wastes. Stairways, closets and corners were often fouled and the populace became accustomed to the stench and the sight of people relieving themselves in public. In Erasmus’ writings on etiquette, he declared it was most rude to observe someone relieving themselves (although he doesn’t appear to condemn those doing the relieving).

Prior to the Conquest of Central and South America by the Spanish, complex sewerage systems had been constructed. In Tenochtitlan, the Aztec Capital (now Mexico City), there existed public fountains for drinking and bathing and waste was discharged to a series of lakes via a system of clay pipes. Public hygiene was catered for, and the populace was able to bathe daily – something alien to even wealthy Europeans of the time. Waterborne diseases were not common (as in London), despite the fact that the city was built in the middle of a lake on a set of man-made islands. One of the first acts of the Conquistadors was to destroy the Aztec flood defences and water control measures and to start filling in the lakes. Ever since, the government of Mexico City has been fighting successive periods of flood and drought. The centre of Mexico City is sinking at an alarming rate as the huge population continues to withdraw groundwater at a faster rate than it can be replaced naturally.

In Victorian London, disease was rife. The 1848-49 cholera outbreak shocked the population when it killed more than 50,000 of the city’s inhabitants. City-dwellers lived in constant fear that disease could take their lives with little warning. In the mid-19th century, a Londoner’s life expectancy was shockingly low: forty-five for a “gentleman” and mid-twenties for a tradesman.

Storm water and sewage were diverted into the River Thames by a rudimentary system of pipes and underground sewers. The huge amounts of nutrients deposited into it daily caused the successive growth of algae and bacteria which used up the dissolved oxygen, killing most of the organisms in the water. The sewerage system co-existed with the old method of dealing with human excrement—the “night soil” men, who hauled the waste that literally filled up the basements of houses to farms on the edge of the city. Previous generations had grown used to the “urine tax”. This forced families to urinate on the same patch of earth in the corner of the house. This would be dug up periodically to be turned into saltpetre – one of the major ingredients of gunpowder. It’s a little-known fact that it was the wee of the British peasant that ensured that Britain became a world superpower.

As London grew, human waste seeped from the Thames into the underground rivers that were one of the city’s main water supplies. Ironically, the man in charge of this was London’s sanitation commissioner, Edwin Chadwick. An adherent of the Miasma Theory, which held that cholera was transmitted through a foul stench in the air, Chadwick believed that dumping waste into the river, away from residences, would prevent further outbreaks of the disease. Of course, by contaminating London’s main water supply, he greatly contributed to the spread of the disease.

In 1857 the stench from the river was so great that Parliament could not meet. Heavy curtains soaked in lime were hung over the windows to prevent the odour from permeating the building, without success. Amusingly this became known as “The Great Stink”. A cynic might say that as is often the case, something was only done because it directly affected politicians. Interestingly, it appears that it was the smell which was affecting the gears of democracy, not the preventable deaths of thousands of subjects every year. However, the Great Stink did lead directly to action, and the construction of the first modern effective sewerage system.

Joseph Bazalgette, a civil engineer and Chief Engineer of the Metropolitan Board of Works, was given responsibility for the work. He designed an extensive underground sewerage system that diverted waste to the Thames Estuary, downstream of the main centre of population. Six main interceptor sewers, totalling almost 100 miles (160 km) in length, were constructed. Bazalgette saw to it that the flow of foul water from old sewers and underground rivers was intercepted, and diverted along new, low-level sewers. Although proper treatment works were not constructed until many years later, the unforeseen consequence of the work was that groundwater was no longer contaminated with sewage, therefore stemming the spread of cholera and other waterborne diseases.

Bazalgette is now the great hero of sewage workers throughout the world. He is commemorated by a blue plaque on his house in St John’s Wood, London, and a memorial on Victoria Embankment above one of the sewers he designed. He was one of the first of a generation of British engineers with a social conscience.

Cities such as Nairobi and Dhaka have populations approaching 20 million, while the population of Mexico City is even greater, yet their struggle with a lack of clean drinking water and an inadequate public health system go largely unnoticed. The answers to these problems will come in part only with massive investments in these cities’ infrastructures, but both the scale and cultural differences of these cities will require new approaches and a new awareness of the history of sewage.