In 18th-century London, water was delivered to the city's residents through hollowed-out tree trunks running beneath the streets. Wealthier customers could buy spring water from private companies, but most residents used the sluggish, murky water of the Thames. Like many European rivers, the Thames was both the source of the city's drinking water and the repository of its discharge. It was also crowded with boats and barges, since it served as the city's main thoroughfare for commercial shipping. No attempt was made to filter the water or protect it from pollution until the middle of the 19th-century.
In 1771, Tobias Smollet wrote, "If I would drink water, I must quaff the mawkish contents of an open aqueduct, exposed to all manner of defilement, or swallow that which comes from the River Thames, impregnated with all the filth of London and Westminster. Human excrement is the least offensive part of the concrete, which is composed of all the drugs, minerals, and poisons used in mechanics and manufacture, enriched with the putrefying carcases of beasts and men, and mixed with the scourings of all the wash-tubs, kennels and common sewers within the bills of mortality." (5)
In fact, water was so suspect that in the first half of the century, a huge gin craze swept London. Gin was tasty, intoxicating, unregulated and cheap. The rule of the day was "Drunk for 1d., dead drunk for 2d., straw for nothing." Gin sellers set up on street corners and along highways, selling to any passer-by who expressed thirst. In London alone, there were 8,000 places where gin was openly sold. Henry Fielding wrote in 1751, "Gin...is the principal sustenance (if it may be so called) of more than a hundred thousand people in this metropolis. Many of these Wretches there are, who swallow Pints of this Poison within the Twenty Four Hours: the Dreadfull Effects of which I have the Misfortune every Day to see, and to smell too."
Sanitation in the 1700s was simply unheard of. Private bathrooms, later known as "water closets," did not exist until late in the century, and even then, they only appeared in the wealthiest of homes. Most London residents used chamberpots, dumping them right outside their windows. The raw sewage would accumulate and stagnate in cesspools until the night soil men came along to clear it all out.
There is no doubt that the sanitation systems, wells and public water supply systems became intermingled. A complex network of sewers did exist in London, but they were designed to carry rainwater rather than sewage. However, records of public complaints suggest that the drains carried much more than that - including the refuse of pigsties and slaughterhouses.
In addition, the city's underground pipes were poorly constructed, so water mains would regularly burst, creating sudden springs on city streets. These springs would carry and mix all of the city's debris together in a sort of running fetid soup that pedestrians would have to slosh through in order to get to their destination.