The Wonders of a London Water Drop
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Victor Hugo saw open sewers—such as London's pre-Bazalgette sewers—as the conscience of the city, arguing that sewers unveiled the city's excretion and made visible the sincerity of filth. The development of modern sewers led to the removal of human excrement from the urban surface, distancing many citizens from the metabolic marriage of water and human waste. In the process, "shit" turned into "sewage." As human waste was swept under city streets, its associations in the collective imaginary changed radically; it became indicative of "disorder, decay and physical repulsion." The boundary between the surface of the city and the underground sewer formalised as one between the visible, rational, civilised, clean and orderly, and the invisible, irrational, uncivilised, dirty and chaotic. Sewers thus became sites for marginality and monstrous mythologies, acting as forgetting wells where society's undesirables can be cleared from the surface and kept out of sight, and out of mind.
According to Stephen Graham,
By carrying filth as well as water, sewers also helped sustain modern ideas of the orderly, mobile and fragrant city; new concepts of bodily and urban hygiene; new styles of household consumption; and new disciplines of urban engineering. Sewers thus became central to a powerfully technocratic ideology of managing the city’s flows and circulations through a series of scientifically constructed infrastructural edifices.
The management of sewerage (the provision of drainage by sewerage) was often employed in questioning the legitimacy of different states or political agents, and was a source of competition between cities and nations. It led to the marginalisation of more rural areas without such networks of subterranean infrastructure. On a practical level, functional sewage systems were essential to the growth and development of metropolises; London throughout most of the 1800s suffered outbreaks of cholera—a disease directly attributable to contaminated water. With the provision of filtrated and sanitised water from the Thames, the city's population was able to expand exponentially; allowing for increasing numbers living in megacities today.
However, the increase in human bodies is a heavy load. As part of the city's metabolic system, sewers act as intestines—processing nutrients (clean water) as well as filtering out the dangerous substances of biological "chaosmosis" (from faeces to all manner of substances we now flush down the toilet). Despite the physical boundary apparently separating it from the urban surface, the underground network of sewers is in fact an intrinsic part of the modernised city, lurking threateningly in opposition to the rationalised and sanitised urban surface. The boundary separating them is in fact extremely fragile and permeable: "at any time what’s down below can rear up and challenge the clean and rational city above." What was intended to be flushed away, never to be seen by the civilised world, reveals itself. This process of emergence can take many forms: human waste may accumulate and create blockades in the form of fatbergs or concretebergs, requiring intervention; contaminants in the water may disperse through the pipes, causing health crises; and storms or other environmental conditions may flood sewage capacities to overflow into open areas, affecting the quality of water and killing wildlife.
Throughout the history of London, the Thames and other rivers were—and arguably still are—considered "natural channels for the disposal of waste." Miasma theory, the belief that noxious air was the source the epidemics, hastened the abandonment of cesspools and favoured flushing all waste into the Thames. The 1859 Bazalgette sewers, a combined system designed to collect rainwater, industrial wastewater, and domestic water, represent the first—and to date, the only—attempt at managing and treating human waste. It significantly decreased the amount of waste being discharged directly into the Thames, but was left exposed to fluctuating conditions, such as flooding, changing climates, war-time destruction, or population growth beyond the limits of infrastructure capacity. Today, work is underway for a new "super sewers" system, also called the "Thames Tideway Tunnel." The scheme would dig deeper in London's underground and expand the sewage system to support a growing population. Although the exact capacity of the Tideway scheme are uncertain, it seems likely that, by 2100, London's population will outgrow the limits of this infrastructure and face similar challenges to those encountered today.
Source: Graham, S. (2018). Vertical: The City from Satellites to Bunkers. London: Verso.