Dyffryn Ardudwy STW - Secondary Wastewater Treatment Plant in Llanenddwyn, Gwynedd

Dyffryn Ardudwy STW is a wastewater treatment plant located in Llanenddwyn, Gwynedd, Wales, serving a population of around 3,300. The plant is situated near the coast of Cardigan Bay, an area known for its scenic beauty and ecological importance. As a secondary treatment facility, it provides biological treatment to reduce organic matter and suspended solids before discharge. The plant operates under the UK's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The designed capacity of 3,299 population equivalent aligns with the population served, indicating appropriate sizing. Treated wastewater is discharged into the local coastal waters, contributing to the protection of marine ecosystems. The receiving environment is Cardigan Bay, part of the Irish Sea, which supports diverse marine life including bottlenose dolphins, seals, and important fish populations. The plant's coastal location necessitates careful management to minimize nutrient and pollutant loads, helping to maintain water quality standards and protect sensitive habitats.

The plant discharges into the coastal waters of Cardigan Bay, an inlet of the Irish Sea. This area is ecologically sensitive, supporting diverse marine life such as bottlenose dolphins, harbor porpoises, and seabirds. The bay's waters are influenced by tidal flows and freshwater inputs from local rivers, making nutrient management critical to prevent eutrophication and maintain healthy ecosystems.