Biggar STW - Secondary Wastewater Treatment Plant in Thankerton, Scotland

Biggar STW (Sewage Treatment Works) is located in Thankerton, South Lanarkshire, Scotland, United Kingdom. The plant serves a population of approximately 3,011 people and operates under secondary treatment standards, which is the baseline requirement for inland freshwater discharges under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant has a designed capacity of 3,700 m³/day and currently discharges an average of 670.35 m³/day of treated effluent. As a secondary treatment facility, it employs biological treatment processes to reduce organic matter and suspended solids before discharge. The plant is situated inland, more than 10 km from the coast, and its treated effluent likely enters a local watercourse that drains into the River Clyde or a tributary, eventually reaching the Firth of Clyde and the Irish Sea. The receiving water body supports diverse aquatic life and is part of Scotland's river basin management framework under the Water Framework Directive. The plant's compliance with secondary treatment standards helps protect downstream ecosystems and water quality in the region.

Biggar STW discharges treated effluent into a local watercourse within the Clyde river basin, which flows into the Firth of Clyde and ultimately the Irish Sea. The downstream environment includes freshwater habitats that support salmonid fish and other aquatic species. The plant's secondary treatment helps reduce nutrient loading and organic pollution, contributing to the ecological health of the catchment.