CASTLE CARY STW - Secondary Wastewater Treatment Plant in Castle Cary, Somerset

CASTLE CARY STW is a wastewater treatment plant located in Castle Cary, Somerset, England. It serves a population of approximately 3,366 people, classifying it as a small agglomeration under UK and EU regulatory frameworks. The plant is situated inland, more than 10 km from the coast, and discharges treated effluent into local watercourses. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for inland freshwater discharges from agglomerations of this size. The designed capacity is 5,433 m³/day, with an average discharge volume of 749.39 m³/day, indicating operational headroom. As a UK facility, it operates under environmental permits issued by the Environment Agency, ensuring compliance with discharge quality standards. The treated effluent from CASTLE CARY STW ultimately drains into the River Brue catchment, which flows through the Somerset Levels and into the Bristol Channel. This region supports diverse aquatic habitats and is important for migratory birds. The plant's secondary treatment helps protect water quality in the sensitive lowland river system.

CASTLE CARY STW discharges into the River Brue catchment, which flows through the Somerset Levels and into the Bristol Channel. The Somerset Levels are a low-lying wetland area of ecological importance, supporting diverse aquatic life and migratory bird populations. The plant's secondary treatment helps maintain water quality in this sensitive downstream environment.