Pirbright Hockford STW - Woking, England Wastewater Treatment Plant

Pirbright Hockford STW is a wastewater treatment plant located near Woking in Surrey, England. It serves a population of approximately 16,400 people, classifying it as a medium-sized agglomeration under UK and EU regulatory frameworks. As a UK plant, it operates under the Urban Waste Water Treatment Regulations, which transpose the EU Urban Waste Water Treatment Directive. For agglomerations of this size, secondary treatment is typically required, with additional nutrient removal if discharging into sensitive areas. It is expected to meet these standards. The plant's treated effluent is discharged into the local watercourse, which flows into the River Wey and ultimately the River Thames. The Thames Basin supports diverse aquatic life and is an important ecological corridor in southeastern England. The plant plays a key role in protecting water quality in this densely populated region.

The plant discharges into the River Wey catchment, a tributary of the River Thames. The Thames flows through London into the North Sea. The local watershed supports chalk stream habitats, which are ecologically sensitive and host species such as brown trout and water voles. Protecting water quality in this basin is critical for maintaining biodiversity and recreational use.