Maidstone and Aylesford STW: Large Wastewater Treatment Plant in Tonbridge and Malling, Kent

Maidstone and Aylesford STW is a wastewater treatment plant located in Tonbridge and Malling, Kent, England. It serves a population of approximately 119,870, classifying it as a large agglomeration under UK wastewater regulations. The plant is situated in the Medway catchment area, which drains into the Thames Estuary. As a large treatment facility, it is expected to provide at least secondary treatment under the Urban Waste Water Treatment Directive (91/271/EEC), as transposed into UK law. The plant's designed capacity is 1.00, indicating a significant treatment volume. Regulatory oversight is provided by the Environment Agency, which issues permits under the Environmental Permitting Regulations. The treated effluent from the plant ultimately discharges into the River Medway, which flows into the Thames Estuary and then the North Sea. This water body supports diverse aquatic life and is an important ecological corridor. The plant plays a key role in protecting water quality in the Medway catchment and downstream marine environment.

The plant discharges into the River Medway, which flows through Kent and into the Thames Estuary, a major ecological zone supporting migratory fish, birds, and marine species. The Medway catchment is designated as a sensitive area under the Urban Waste Water Treatment Directive, requiring enhanced treatment to prevent eutrophication. Downstream, the Thames Estuary is a critical habitat for wintering waterfowl and supports commercial fisheries.