ARRIANDI Wastewater Treatment Plant, Iurreta, Basque Country, Spain

ARRIANDI is a wastewater treatment plant located in Iurreta, within the Basque Country (Euskadi), Spain. It serves a population equivalent of 85,895, classifying it as a medium-to-large agglomeration under EU regulations. The plant's designed capacity is 1. As a Spanish facility, ARRIANDI operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size. For sensitive areas, tertiary treatment may be required. The plant's compliance with these standards ensures proper treatment before discharge. The treated effluent from ARRIANDI likely discharges into a local watercourse that drains into the Bay of Biscay, part of the Atlantic Ocean. The Basque Country's rivers, such as the Nervión or Ibaizabal, flow through industrial and urban areas, making effective wastewater treatment crucial for protecting downstream aquatic ecosystems and coastal water quality.

The plant's discharge likely enters a tributary of the Ibaizabal or Nervión river system, which flows through the Basque Country and empties into the Bay of Biscay. This coastal region supports diverse marine life and is important for fisheries and tourism. Effective treatment helps prevent nutrient enrichment and contamination that could harm estuarine and coastal habitats.