Castlederg Wastewater Treatment Plant, Castlederg, Northern Ireland

Castlederg wastewater treatment plant is located in the town of Castlederg, County Tyrone, Northern Ireland, within the Derry and Strabane District. The plant serves a population of approximately 4,858 people, classifying it as a small agglomeration under EU classification. As a plant in the United Kingdom, Castlederg operates under the Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for discharges to freshwater and estuaries for agglomerations of this size. The designed capacity is 1.00 (likely in megaliters per day or similar unit), indicating a facility scaled to the local population. The plant discharges treated wastewater into a local watercourse, which flows into the River Derg and eventually into Lough Foyle, an important estuarine environment on the north coast of Ireland. This water body supports diverse aquatic life and is a key habitat for migratory fish species.

The treated effluent from Castlederg plant enters a local tributary of the River Derg, which flows northward into Lough Foyle, a large sea lough on the border of Northern Ireland and the Republic of Ireland. Lough Foyle is an ecologically sensitive estuarine environment that supports diverse bird populations and serves as a nursery for commercially important fish species. The plant's discharge must meet quality standards to protect this downstream ecosystem.