LLANFAES STW - Secondary Wastewater Treatment Plant in Llanfaes, Wales

LLANFAES STW (Sewage Treatment Works) is a municipal wastewater facility located in Llanfaes, a village on the Isle of Anglesey in Wales, United Kingdom. The plant serves a population of approximately 2,200 and is situated near the coast, reflecting the area's coastal geography. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for discharges into coastal waters. With a designed capacity of 10,613 cubic meters per day and an actual discharge volume of about 490 cubic meters per day, the plant operates well below its capacity, indicating headroom for future growth or seasonal variations. The treated effluent is discharged into the Menai Strait, a narrow tidal channel that separates Anglesey from mainland Wales. The Menai Strait flows into the Irish Sea, a key marine environment supporting diverse wildlife including seabirds, seals, and important fisheries. The plant's coastal location means its discharge is subject to stringent environmental standards to protect the sensitive marine ecosystem.

The plant discharges into the Menai Strait, a dynamic tidal channel connecting the Irish Sea to the inland waters of Anglesey. This strait supports a rich diversity of marine life, including important habitats for seabirds and marine mammals. The coastal environment is ecologically sensitive, and the plant's secondary treatment helps minimize nutrient and pollutant loads to the sea, contributing to the overall health of the Irish Sea basin.