The structural rehabilitation design of the buried tank at Prezero’s waste management facility, located in the Les Franqueses del Vallès industrial estate, was developed. The scope included defining demolition, repair and strengthening works for the existing structural elements (walls, columns, beams and slab), which had been affected by deterioration and corrosion processes caused by chemical attack from wastewater. The main objective is to restore structural capacity and ensure the tank’s durability and structural safety by improving its condition and extending its service life.