Mogden Sewage Treatment Works

Mogden Sewage Treatment Works is a sewage treatment plant in the Ivybridge section of Isleworth, west London, England, formerly known as Mogden. Built in 1931–36 by Middlesex County Council and now operated by Thames Water, it is the third largest sewage works in the United Kingdom. The site covers 55 hectares (140 acres).

It treats the waste water from three main sewers serving the northwest quarter of Outer London and two further ones from the south and south-west.