Sion Mills Wastewater Treatment Plant - County Tyrone, Northern Ireland

Sion Mills wastewater treatment plant is located in the village of Sion Mills, County Tyrone, Northern Ireland. It serves a population of approximately 3,544 residents and operates under the regulatory framework of the United Kingdom, which implements the EU Urban Waste Water Treatment Directive (91/271/EEC). As a small agglomeration, the plant is required to provide secondary treatment, which it does, ensuring compliance with national standards. The plant has a designed capacity of 4,950 cubic meters per day and currently discharges an average volume of 789 cubic meters per day. The treatment process involves secondary treatment, which typically includes biological processes to reduce organic matter and suspended solids. The plant's operations are overseen by the Northern Ireland Environment Agency, which issues discharge consents under the Water (Northern Ireland) Order 1999. The treated effluent is discharged into a local watercourse that flows into the River Foyle, eventually reaching Lough Foyle and the Atlantic Ocean. The River Foyle is an important salmon and trout fishery, and the plant's discharge must meet strict quality standards to protect aquatic life and downstream ecosystems. The plant plays a vital role in maintaining water quality in the Foyle catchment.

The plant discharges into a tributary of the River Foyle, which flows north into Lough Foyle, a large sea lough on the north coast of Ireland. The Foyle catchment supports diverse aquatic life, including Atlantic salmon and European eel, and is designated as an important migratory corridor. The plant's secondary treatment helps protect these species from nutrient pollution and oxygen depletion.