Overton STW: Wastewater Treatment Plant in Basingstoke and Deane, England

Overton STW is a wastewater treatment works located in Overton, near Basingstoke and Deane in Hampshire, England. The plant serves a population of approximately 4,228 and operates as part of the United Kingdom's municipal wastewater infrastructure. The facility provides secondary treatment, which is the standard level required under UK regulations for inland plants of this scale. The plant has a designed capacity of 4,228 population equivalent and discharges 941.30 m³/day of treated effluent. As a UK plant, it operates under the Water Industry Act 1991 and is regulated by the Environment Agency. The treated effluent from Overton STW is discharged into a local watercourse, likely a tributary of the River Test or River Kennet, both of which are chalk streams supporting diverse aquatic life. These rivers eventually drain into the English Channel, contributing to the ecological health of the Hampshire region.

The plant discharges into a local watercourse that feeds into the River Test or River Kennet, both ecologically sensitive chalk streams known for their rich biodiversity, including salmonid fish and aquatic invertebrates. These rivers flow into the Solent and ultimately the English Channel. The surrounding area is rural and agricultural, so the plant's discharge helps maintain water quality in a region where nutrient management is important.