Partridge Green STW: Secondary Wastewater Treatment in Horsham, England

Partridge Green STW is a wastewater treatment plant located in Partridge Green, near Horsham in West Sussex, England. It serves a population of approximately 2,520 people, classifying it as a small agglomeration under UK wastewater regulations. The plant is situated inland, more than 10 km from the coast, and its treated effluent is discharged into local watercourses. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. The UK has transposed this directive into national law, ensuring that treatment meets biological oxygen demand and suspended solids standards. The plant's designed capacity is 2,520 population equivalent, and it currently treats an average daily flow of 561 cubic meters. The treated wastewater from Partridge Green STW ultimately drains into the River Adur catchment, which flows south to the English Channel. The river supports diverse aquatic life and is an important habitat for species such as brown trout and European eel. The plant's discharge contributes to maintaining water quality in this sensitive chalk stream environment.

Partridge Green STW discharges into the River Adur catchment, a chalk stream system that flows through the Sussex Downs to the English Channel. Chalk streams are globally rare and support diverse aquatic ecosystems, including brown trout, grayling, and water crowfoot. The plant's secondary treatment helps protect downstream water quality and the ecological health of this sensitive riverine environment.