COLERNE STW - Secondary Wastewater Treatment Plant in Colerne, Wiltshire

COLERNE STW is a wastewater treatment plant located in Colerne, Wiltshire, England, serving a population of around 2,586. The plant is situated inland, more than 10 km from the coast, and operates under the regulatory framework of the United Kingdom, which implements the EU Urban Waste Water Treatment Directive (UWWTD) for agglomerations of this scale. The plant provides secondary treatment, which is the standard required by the UWWTD for inland freshwater discharges from populations between 2,000 and 10,000. With a designed capacity of 4,616 m³/day and an average daily discharge volume of 575.73 m³, the facility operates well within its capacity, ensuring effective treatment of municipal wastewater. Treated effluent from COLERNE STW is discharged into local watercourses that eventually drain into the Bristol Channel via the River Avon system. This contributes to the protection of downstream aquatic ecosystems and supports the ecological health of the region's rivers and estuaries.

COLERNE STW discharges into local streams that are part of the Bristol Avon catchment, which flows into the Bristol Channel. The receiving waters support diverse aquatic life and are important for migratory fish species. The plant's secondary treatment helps reduce nutrient and organic loads, protecting downstream habitats from eutrophication and maintaining water quality standards.