The Metropolis Water Act 1852 was enacted "to make provision for securing the supply to the Metropolis of pure and wholesome water". Under the Act, it became unlawful for any water company to extract water for domestic use from the tidal reaches of the Thames after 31 August 1855, and from 31 December 1855 all such water was required to be "effectually filtered". In the meantime, an outbreak of cholera in 1854 led to the deaths of an estimated 4,267 people supplied by the company.