Operation of the Rioja Baja - Alhama wastewater treatment plant
"The exploitation and maintenance service of the treatment facilities of the Rioja Baja Alahama region is composed of twelve wastewater treatment plants for the municipalities of Alfaro, Aldeanueva, Rincón de Soto, Cervera, Aguilar, Igea, Rincón de Olivedo, Valverde, Grávalos, Cornago, Ventas del Baño and Cabretón. These plants are designed for a total population equivalent of 75,860 and treat over 14,000 m3/day. These facilities are equipped with different wastewater treatment systems, such as extended aeration, low-load trickling filter and subsurface flow wetlands. The sludge generated during the secondary treatment undergoes a centrifugal dewatering process with the use of polyelectrolytes. This sludge is stored in silos for subsequent use in agriculture."