Harlington STW - Secondary Wastewater Treatment Plant in Doncaster, England

Harlington STW is a wastewater treatment plant located in Harlington, near Doncaster, South Yorkshire, England. It serves a population of approximately 2,086 people, classifying it as a small agglomeration under UK water industry standards. The plant is situated inland, away from coastal areas, and its operations are part of the regional water management infrastructure. The plant provides secondary treatment, which is the standard biological treatment stage required for municipal wastewater in the UK under the Urban Waste Water Treatment (England and Wales) Regulations. Secondary treatment typically involves biological oxidation and settlement to reduce organic matter and suspended solids. The plant has a designed capacity of 2,224 m³/day and currently discharges 464.42 m³/day, indicating it operates well below its capacity. The treated effluent from Harlington STW is discharged into local watercourses that ultimately drain into the River Don catchment, which flows into the Humber Estuary and the North Sea. The plant plays a role in protecting the water quality of these downstream environments, supporting aquatic life and recreational uses in the region.

Harlington STW discharges into local watercourses that are part of the River Don basin. The River Don flows through South Yorkshire and joins the River Ouse near Goole, eventually reaching the Humber Estuary, a major ecological site supporting diverse birdlife and fish populations. The plant's secondary treatment helps reduce nutrient and organic loads, contributing to the health of this downstream ecosystem.