The Great Stink, or the Big Stink, was a time in the summer of 1858 during which the smell of untreated human waste and effluent from other activities was very strong in central London. The stench was also (wrongly) associated with cholera outbreaks and prompted London authorities to accept a sewerage scheme proposed by engineer Joseph Bazalgette, implemented during the 1860s.
Until the late 16th century, London citizens were reliant for their water supplies on water from shallow wells, the River Thames, its tributaries, or one of around a dozen natural springs, including the spring at Tyburn which was connected by lead pipe to a large cistern or tank (then known as a conduit): the Great Conduit in Cheapside. So that water was not abstracted for unauthorised commercial or industrial purposes, the city authorities appointed keepers of the conduits who would ensure that users such as brewers, cooks and fishmongers would pay for the water they used.
Wealthy Londoners living near to a conduit pipe could obtain permission for a connection to their homes, but this did not prevent unauthorised tapping of conduits. Otherwise, particularly for households which could not take a gravity-feed, water from the conduits was provided to individual households by water carriers, or "cobs". In 1496 the "Water Carriers" formed their own guild called "The Brotherhood of St. Cristofer of the Waterbearers."
In 1582 Dutchman Peter Morice leased the northernmost arch of London Bridge and, inside the arch, constructed a waterwheel that pumped water from the Thames to various places in London. Further waterwheels were added in 1584 and 1701, and remained in use until 1822.
However, in 1815 house waste was permitted to be carried to the Thames via the sewers, so for seven years human waste was dumped into the Thames and then potentially pumped back to the same households for drinking, cooking and bathing. Prior to the Great Stink there were over 200,000 cesspits in London. Emptying one cesspit cost a shilling - a cost the average London citizen then could ill afford. As a result, most cesspits added to the airborne stench.
Part of the problem was due to the introduction of flush toilets, replacing the chamber pots that most Londoners had used. These dramatically increased the volume of water and waste that was now poured into existing cesspits. These often overflowed into street drains designed originally to cope with rainwater, but now also used to carry outfalls from factories, slaughterhouses and other activities, contaminating the city before emptying into the River Thames.
The summer of 1858 was unusually hot. The Thames and many of its urban tributaries were overflowing with sewage; the warm weather encouraged bacteria to thrive.
The resulting smell was so overwhelming that it affected the work of the House of Commons (countermeasures included draping curtains soaked in chloride of lime, while members considered relocating upstream to Hampton Court) and the law courts (plans were made to evacuate to Oxford and St Albans).
Heavy rain finally ended the heat and humidity of summer and the immediate crisis ended. However, a House of Commons select committee was appointed to report on the Stink and recommend how to end the problem. A bill was rushed through Parliament and became law in 18 days, to provide more money to construct a massive new sewer scheme for London, and to build the Embankment along the Thames in order to improve the flow of water and of traffic.
Cholera became widespread during the 1840s. The causes were not known; the most widely accepted notion was that the disease was due to air-borne "miasma". Because of the miasmatic theory's predominance among scientists, the 1854 discovery by Filippo Pacini of Vibrio cholerae, the bacterium that caused the disease, was ignored until it was rediscovered thirty years later by Robert Koch. In 1854 London physician Dr John Snow discovered that the disease was transmitted by drinking water contaminated by sewage after an epidemic centred in Soho, but this idea was not widely accepted. Consolidating several separate local bodies concerned with sewers, the Metropolitan Commission of Sewers was established in 1848; it surveyed London's antiquated sewerage system and began ridding the capital of its cesspits—an objective later accelerated by the "Great Stink".
The consolidated Commission was superseded in 1855 by the Metropolitan Board of Works which, after rejecting many schemes for "merciful abatement of the epidemic that ravaged the Metropolis", accepted a scheme to implement sewers proposed in 1859 by its chief engineer, Joseph Bazalgette. The intention of this very expensive scheme was to resolve the epidemic of cholera by eliminating the stench which was believed to cause it. Over the next six years the main elements of the London sewerage system were created. As an unintended consequence the water supply ceased to be contaminated; this resolved the cholera epidemic.
John Martin was also occupied with schemes for the improvement of London, and published various pamphlets and plans dealing with the metropolitan water supply, sewerage, dock and railway systems (his 1834 plans for London's sewerage system anticipated by some 25 years the 1859 proposals of Bazalgette to create intercepting sewers complete with walkways along both banks of the River Thames).
Although the new sewerage system was in operation, and water supplies gradually improved, it did not prevent a later epidemic during the 1860s, especially in east London. However, a forensic investigation by Captain Tyler of the Railway Inspectorate in 1867 showed that the polluted River Lea was entering reservoirs of the East London Water Company, and so caused the epidemic. The water-borne explanation had now been proved beyond doubt, and eliminating the source of pollution resolved this last epidemic of cholera in the capital.
All of these occupations were considered to be of low social class.
Henry Moule (1801–1880), English pastor of the Church of England saw a connection between the conditions of hygiene and the expansion of disease; he turned his attention to sanitary science. The outbreak of cholera in 1854 and the Great Stink gave him impetus in 1859 to experiment with his dry earth closet, for which he filed a patent in 1860. His system was adopted in private houses, in rural districts, in military camps, in many hospitals, and extensively in the British Raj.