“The project involves the implementation of works to upgrade the sewage treatment plant serving the Castro agglomeration. The intervention, in particular, aimed to increase the plant’s capacity from 24,496 to 28,654 A.E. The work involved the construction of a new pretreatment compartment, a new water treatment line (biological tank and final sedimenter), and a new filtration compartment. At the same time, the aerobic stabilization compartment and the mechanical sludge dewatering section were upgraded. Lastly, as part of the intervention, the final delivery of the plant was upgraded by constructing a new trench with a dispersing surface area of about 4,000 m2.”