Dalmellington STW - Secondary Wastewater Treatment Plant in East Ayrshire, Scotland

Dalmellington STW is a wastewater treatment plant located in Dalmellington, East Ayrshire, Scotland. It serves a population of 3,564 and is part of the region's municipal wastewater infrastructure. The plant is situated inland, more than 10 km from the coast, and its treated effluent is discharged into local watercourses that drain into the Irish Sea via the River Doon and the Firth of Clyde. The plant provides secondary treatment, which is the standard level required under the Urban Waste Water Treatment (Scotland) Regulations for inland agglomerations of this size. With a designed capacity of 6,000 m³/day and an average discharge volume of 793.47 m³/day, the plant operates well within its capacity. The regulatory framework in Scotland is aligned with the EU Urban Waste Water Treatment Directive, ensuring that discharges meet environmental quality standards. The receiving water bodies ultimately flow into the Firth of Clyde, a major estuary that supports diverse aquatic life and is important for migratory fish species. The plant's discharge is managed to protect downstream water quality and the ecological health of the Doon Valley and the wider Clyde catchment.

Dalmellington STW discharges into local watercourses that flow into the River Doon, which drains into the Firth of Clyde. The Firth of Clyde is a large estuary supporting diverse marine and freshwater habitats, including important salmon and sea trout populations. The plant's secondary treatment helps protect these downstream ecosystems from nutrient enrichment and organic pollution.