ISSO Wastewater Treatment Plant, Hellín, Castilla-La Mancha, Spain

ISSO is a wastewater treatment plant located in the Barrio Quílez area of Casas del Río, within the municipality of Hellín in the province of Albacete, Castilla-La Mancha, Spain. The plant serves a population of 2,394 and operates at a secondary treatment level, which is appropriate for a small agglomeration under Spanish and EU regulations. As a secondary treatment facility, ISSO provides biological treatment to reduce organic matter and suspended solids. The plant discharges an average of 330.15 cubic meters per day of treated wastewater. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), agglomerations of this size are required to have secondary treatment, which ISSO meets. The treated effluent from ISSO is discharged into the local water system, which ultimately drains into the Segura River basin. The Segura River flows through southeastern Spain and discharges into the Mediterranean Sea. The plant plays a key role in protecting the water quality of the Segura River and its tributaries, supporting aquatic life and downstream uses.

ISSO discharges into the Segura River basin, which flows through the arid region of southeastern Spain before reaching the Mediterranean Sea. The Segura River supports diverse aquatic life and is an important water resource for agriculture and urban areas. The plant's secondary treatment helps reduce nutrient and organic pollution, mitigating eutrophication risks in the river and coastal waters.