London Mogden STW - Major Wastewater Treatment Plant in Greater London

London Mogden STW is a major wastewater treatment plant located in the London Borough of Richmond upon Thames, serving approximately 1.96 million people in Greater London. It is one of the largest treatment facilities in the United Kingdom, situated along the River Thames. As a large agglomeration serving over 150,000 people, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment as a minimum. For sensitive areas like the Thames estuary, tertiary treatment may be mandated to reduce nutrients and protect water quality. The plant's treated effluent is discharged into the River Thames, which flows eastward through London and into the Thames Estuary, eventually reaching the North Sea. The Thames supports diverse aquatic life and is an important ecological corridor, with the estuary providing critical habitat for birds and fish.

The plant discharges into the River Thames, which flows through London and into the Thames Estuary, a major ecological zone that supports diverse aquatic life, including migratory fish and overwintering birds. The estuary is a key part of the North Sea ecosystem, and nutrient inputs from wastewater must be managed to prevent eutrophication. The plant's location in a densely populated urban area means its discharge quality directly affects the health of the river and downstream marine environment.