The Great Stink was an event in Central London during July and August 1858 in which the hot weather exacerbated the smell of untreated human waste and industrial effluent that was present on the banks of the River Thames. The problem had been mounting for several years, with an ageing and inadequate sewer system that emptied directly into the Thames. The miasma from the effluent was thought to transmit contagious diseases, and three outbreaks of cholera before the Great Stink were blamed on the ongoing problems with the river.
Background
Brick sewers had been built in London from the 17th century when sections of the Fleet and Walbrook rivers were covered for that purpose. In the century preceding 1856, over a hundred sewers were constructed in London, and at that date the city had around 200,000 cesspits and 360 sewers. Some cesspits leaked methane and other gases, which often caught fire and exploded, while many of the sewers were in a poor state of repair. During the early 19th century improvements had been undertaken in the supply of water to Londoners, and by 1858 many of the city's medieval wooden water pipes were being replaced with iron ones.
This, combined with the introduction of flushing toilets and the rising of the city's population from just under one million to three million, led to more water being flushed into the sewers, along with the associated effluent. The outfalls from factories, slaughterhouses and other industrial activities put further strain on the already failing system. Much of this outflow either overflowed, or discharged directly, into the Thames.
June to August 1858
By June the stench from the river had become so bad that business in Parliament was affected, and the curtains on the river side of the building were soaked in lime chloride to overcome the smell. The measure was not successful, and discussions were held about possibly moving the business of government to Oxford or St Albans. The Examiner reported that Disraeli, on attending one of the committee rooms, left shortly afterwards with the other members of the committee, "with a mass of papers in one hand, and with his pocket handkerchief applied to his nose" because the smell was so bad. The disruption to its legislative work led to questions being raised in the House of Commons.
According to Hansard, the Member of Parliament (MP) John Brady informed Manners that members were unable to use either the Committee Rooms or the Library because of the stench, and asked the minister "if the noble Lord has taken any measures for mitigating the effluvium and discontinuing the nuisance". Manners replied that the Thames was not under his jurisdiction. Four days later a second MP said to Manners that "By a perverse ingenuity, one of the noblest of rivers has been changed into a cesspool, and I wish to ask whether Her Majesty's Government intend to take any steps to remedy the evil?" Manners pointed out "that Her Majesty's Government have nothing whatever to do with the state of the Thames".
Construction
Bazalgette's plans for the 1,100 miles (1,800 km) of additional street sewers (collecting both effluent and rainwater), which would feed into 82 miles (132 km) of main interconnecting sewers, were put out to tender between 1859 and 1865. Four hundred draftsmen worked on the detailed plans and sectional views for the first phase of the building process. There were several engineering challenges to be overcome, particularly the fact that parts of London—including the area around Lambeth and Pimlico—lie below the high-water mark. Bazalgette's plan for the low-level areas was to lift the sewage from low-lying sewers at key points into the mid- and high-level sewers, which would then drain with the aid of gravity, out towards the eastern outfalls at a gradient of 2 feet per mile (38 cm/km).
Bazalgette was a proponent of the use of Portland cement, a material stronger than standard cement, but with a weakness when over-heated. To overcome the problem he instituted a quality control system to test batches of cement, that is described by the historian Stephen Halliday as both "elaborate" and "draconian". The results were fed back to the manufacturers, who altered their production processes to further improve the product. One of the cement manufacturers commented that the MBW were the first public body to use such testing processes. The progress of Bazalgette's works was reported favourably in the press. Paul Dobraszczyk, the architectural historian, describes the coverage as presenting many of the workers "in a positive, even heroic, light", and in 1861 The Observer described the progress on the sewers as "the most expensive and wonderful work of modern times".