BOX STW Wastewater Treatment Plant, Box, Wiltshire, England

BOX STW is a wastewater treatment plant located in Box, Wiltshire, England, serving a population of approximately 2,256. The plant is situated inland, over 10 km from the coast, and provides secondary treatment to municipal wastewater. As a secondary treatment facility, BOX STW meets the standard required by the UK's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for inland agglomerations of this scale. The plant has a designed capacity of 3,271 m³/day and currently treats an average daily flow of 502.26 m³/day, indicating significant spare capacity. The treated effluent is discharged into a local watercourse, likely a tributary of the River Avon or the Bristol Avon system, which flows into the Severn Estuary. This discharge contributes to the protection of downstream aquatic habitats and supports the ecological health of the catchment.

The plant discharges into a local stream that is part of the Bristol Avon catchment, which flows into the Severn Estuary. The Severn Estuary is a major ecological feature supporting diverse fish populations and migratory birds. The secondary treatment provided by BOX STW helps reduce nutrient and organic loads, protecting the downstream riverine and estuarine environments from eutrophication and oxygen depletion.