RHIWSAESON STW - Secondary Wastewater Treatment Plant in Groes-faen, Wales

RHIWSAESON STW (Sewage Treatment Works) is a municipal wastewater facility located in Groes-faen, Rhondda Cynon Taf, Wales, United Kingdom. The plant serves the local community and is situated near the River Ely catchment area. As a secondary treatment plant, it provides biological treatment to remove organic matter and suspended solids before discharge. With a designed capacity of 22,669 cubic meters per day, the plant is sized to handle the wastewater from a medium-sized agglomeration. Under the UK's implementation of the EU Urban Waste Water Treatment Directive (UWWTD), secondary treatment is the standard requirement for inland discharges, ensuring compliance with environmental quality standards. The plant's capacity suggests it serves a population equivalent in the range of tens of thousands. The treated effluent is discharged into local watercourses that flow into the Bristol Channel, a major estuary and marine environment. The plant's proximity to the coast (within 10 km) means its discharge can influence coastal water quality. The receiving waters support diverse aquatic life and are important for recreation and fisheries. The plant plays a key role in protecting the downstream ecosystem from nutrient pollution and pathogens.

The plant discharges into the River Ely catchment, which flows into the Bristol Channel, a large estuary with significant ecological importance. The Bristol Channel supports diverse marine life, including fish, birds, and seals, and is a key migratory corridor. The plant's secondary treatment helps reduce organic load and nutrients, protecting downstream water quality and the sensitive coastal environment from eutrophication.