In the summer of 1858, Londoners found themselves in the middle of a big stinking problem. For centuries, the city was abusing River Thames using it as dumping ground for human excrement and industrial waste resulting in a river that was little more than an open sewer devoid of any fish or other wildlife. The stench rising from the river had been a mounting problem for some years priors to the “Great Stink” of 1858. That year, the weather was unusually hot. In the scorching heat, the sewage floating in the Thames started to ferment and gave off a stench so hideous that at the Parliament, curtains were soaked in chloride of lime in a vain attempt to defeat the fetid smell. When that didn’t work, the lawmakers even considered relocating the entire government from the Westminster area to somewhere west away from the nauseous river. Eventually they decided that rebuilding London’s sewer system was the only possible solution. Within a record eighteen days, a bill was created, passed, and signed into law.
The task of reforming the Thames and implementing a new sewage system fell upon the chief engineer of the Metropolitan Board of Works, Joseph Bazalgette, who had already spent several frustrating years trying to get his ambitious but thorough plan for the city's sewerage system approved. Each plan he submitted was promptly shot down citing one problem or the other. The overpowering smell finally moved the bureaucratic cogwheels and Bazalgette got the go-ahead to begin construction.
This was a time when diseases such as typhoid and the greatly feared cholera were thought to spread by the inhalation of “miasma”, or bad air emanating from decaying matter; the term came from an ancient Greek word meaning pollution. The 'Great Stink' therefore greatly alarmed the population.
Four years earlier, John Snow, one of the fathers of modern epidemiology, while investigating the cholera epidemic of Soho in 1854, correctly deduced that the cause of the disease was contaminated water. Incredibly, Snow managed to trace the source of the outbreak to a single public water pump in Broad Street. Later, it was revealed that the pump was located near a leaking sewer. Although Snow’s germ theory was largely ignored, he did manage to persuade the local council to disable the well pump by removing its handle. Instances of the disease is said to have fell considerably once the pump was disabled.
Nonetheless, the “miasma theory” held sway and it was this notion that diseases spread by bad smell that finally pressed the parliament to seriously reconsider upgrading London’s ailing sewerage system as proposed by Joseph Bazalgette.
Bazalgette’s plan was to take sewage as far as possible from the city through gravity flow and steam-powered pumping engines, and then dump it untreated into the Thames far to the south-east of the city. For this, he constructed a network of intercepting sewers, running parallel to the river, some 82 miles in length. These collected sewage from over 450 miles of existing sewers that themselves received contents from over 13,000 miles of small local sewers, dealing daily with half a million gallons of waste. Construction of the sewers was a stupendous undertaking involving the excavation of 3.5 million cubic yards of earth, and requiring 318 million bricks and 880,000 cubic yards of concrete and mortar. Bazalgette also built three huge embankments along the shores of the Thames inside which ran the sewer lines.
For the most part, the sewage moved by gravity, but in places such as Chelsea, Deptford, Abbey Mills and Crossness, pumping stations were built to to raise the water and provide sufficient flow. Of these, the pumping stations at Abbey Mills and at Crossness were the most architecturally magnificent with ornate domes resembling those of a Byzantine church. The architectural historian Nikolaus Pevsner, described the building’s architecture as "an unorthodox mix, vaguely Italian Gothic in style but with tiers of Byzantine windows and a central octagonal lantern that adds a gracious Russian flavour.”
Bazalgette demonstrated amazing foresight when designing the system. For example, after working out exactly how big the sewer pipes would need to be to support London’s population, Bazalgette reasoned that since they would be building the system only once and there will always be the unforeseen, he went right ahead and doubled the diameter. Thanks to such forward planning, London’s 150-year old Victorian sewage system is still functioning to this day.