User:Victoriatrzaska/Infrastructure in London

Current infrastructure
The only main operational power station in London is the gas-fired 408 MW Enfield power station. Apart from the few redundant but extant power station buildings, the physical infrastructure of the electricity industry in London is largely hidden. Tate Modern still houses an electricity transformer substation. The power lines of the National Grid and local distributors are generally routed underground, see for example Tunnels underneath the River Thames. The economic infrastructure includes the 'big six' energy companies: British Gas, Scottish Power, Npower, E. ON, EDF Energy, and SSE, and several smaller companies.

History


London's water supplies were drawn from the River Thames, the River Lea, the River Brent, the River Colne and springs and wells in the Greater London area. Before 1902 a number of private water companies abstracted, treated and supplied water to their statutory areas. For example, the West Middlesex Waterworks Company supplied the districts of Marylebone and Paddington. From the mid-nineteenth century concerns were raised about the quality of the water supply. Sewage effluent was discharged directly into the tidal river, contaminating the fresh water supply. The Metropolis Water Act 1852 prohibited the abstraction of water for domestic use from the tidal reach of the River Thames, that is from below Teddington Weir. The water companies built water treatment works upriver such as at Hampton.

By the end of the nineteenth century there were eight water companies supplying water to London. The Metropolitan Water Board was established in 1903 to purchase and operate the water facilities of these companies. Water supply was now coordinated by a single authority. The Metropolitan Water Board constructed large raw water storage reservoirs and treatment works in the Lea Valley and to the west of London abstracting water from the Lea and the Thames respectively. These supplies were connected in the 1950s by a 2.6 m diameter tunnel which carried water from the Thames at Hampton to Chingford. Water treatment works were upgraded as new treatment processes were developed. Treatment at water works included rapid gravity filtration, flocculation, sedimentation, dissolved air flotation, slow sand filtration and chlorine and ozone dosing. The Metropolitan Water Board was abolished in 1974 (Water Act 1973) and replaced by the Thames Water Authority. The water industry was privatised in 1989 (Water Act 1989) and the Thames Water Authority became Thames Water, a state regulated private company.