Billingshurst STW Wastewater Treatment Plant, West Sussex, England

Billingshurst STW is a wastewater treatment plant located near Billingshurst, West Sussex, England. It serves a population of around 7,600, classifying it as a small to medium agglomeration under UK regulations. The plant is situated in the rural-urban fringe of the Horsham district. As a UK wastewater facility, Billingshurst STW operates under the Urban Waste Water Treatment (England and Wales) Regulations 1994, which transpose the EU Urban Waste Water Treatment Directive. For a population of this scale, secondary treatment is typically required. The plant has a designed capacity of 1.00 (likely in megalitres per day or similar), indicating a moderate capacity for its service area. The treated effluent from Billingshurst STW is discharged into a local watercourse that ultimately drains into the River Arun. The River Arun flows south through the Sussex Weald and enters the English Channel at Littlehampton. This river supports diverse aquatic life and is important for local biodiversity, including migratory fish species. The plant plays a key role in maintaining water quality in this sensitive chalk-stream influenced catchment.

Billingshurst STW discharges into a tributary of the River Arun, which flows through the Sussex countryside before reaching the English Channel. The River Arun is a lowland river with a mixed geology of clay and chalk, supporting habitats for species such as brown trout and kingfishers. The catchment is designated as a Nitrate Vulnerable Zone under UK regulations, reflecting the need for careful nutrient management to protect downstream water quality and coastal ecosystems.