Chester-le-Street STW: Municipal Wastewater Treatment in County Durham, England

Chester-le-Street STW is a municipal wastewater treatment plant located in Chester-le-Street, County Durham, in the North East of England. The plant serves a population of approximately 32,581, classifying it as a medium-sized agglomeration under UK regulatory frameworks. As a plant in the United Kingdom, Chester-le-Street STW operates under the Urban Waste Water Treatment (England and Wales) Regulations, which transpose the EU Urban Waste Water Treatment Directive 91/271/EEC. For agglomerations of this scale (between 10,000 and 150,000 population equivalent), secondary treatment is typically required, with more stringent tertiary treatment if the receiving waters are designated as sensitive areas. The treated effluent from the plant is discharged into the local water environment, ultimately contributing to the River Wear catchment. The River Wear flows eastward through County Durham and into the North Sea at Sunderland. The plant plays a key role in protecting the water quality of the River Wear and its downstream ecosystems.

The plant discharges into the River Wear catchment, which flows through County Durham before reaching the North Sea at Sunderland. The River Wear supports diverse aquatic life, including salmon and trout populations, and its estuary is an important habitat for migratory birds. The plant's treatment performance is critical to maintaining water quality in this ecologically sensitive river system.