Sorigué has completed the first stage of the remodelling of the La Llagosta Wastewater Treatment Plant (WWTP) in Barcelona, which aims to increase its nutrient removal capacity and achieve the quality values required by current European regulations. The highly complex project involved the commissioning of a new treatment line without suspending the plant's activities at any point. 
 
With a treatment capacity of 43,000 m³ of wastewater per day, covering a population of more than 120,000 inhabitants, the La Llagosta WWTP did not meet the decontamination values set by the European Union, which is why an extension of the facilities was planned in two phases. 
 
In this first stage, which has just been completed, several new structures were built, such as the biological treatment by-pass chamber, the bioreactor with two treatment lines and the secondary decanter and a pumping station for the recirculation and purging of sludge, service water and wastewater. In addition, a flow measurement chamber was installed in biological treatment and at the plant outlet, and the existing bioreactor and secondary decanters were remodelled, as well as the blower building with its respective equipment modernisation.

This hydraulic engineering work ratifies Sorigué's commitment to the whole water cycle and demonstrates its experience in large-scale projects. The

 

extension of these facilities was carried out while the plant was in full operation and with special care since, being a WWTP, it was imperative to avert the risk of accidental spillage of wastewater into the Besòs riverbed. The electrical component, on the other hand, involved high-precision work to connect new electrical switchboards to the previous installations.
 
The second phase of the project will be developed sequentially and will focus on the rehabilitation of two secondary decanters interconnected with the water outlet of the new bioreactor, in addition to the existing ones. Furthermore, part of the existing bioreactor will be left as a storm water tank to absorb part of the increased inflow when it mixes with rainwater, thus preventing spillage and allowing the accumulated flow in this tank to be gradually treated by the plant itself.
 
Located in the municipality of La Llagosta, in the Vallès Oriental region of Barcelona, the La Llagosta WWTP forms part of a set of systems that make up the sanitation system of the Besòs basin. It treats a large part of the discharges from Sentmenat, Palau-solità i Plegamans, Polinyà, Santa Perpetua de la Mogoda, Martorelles, Sant Fost de Campsentelles and Mollet, as well as the wastewater generated by industrial activity in the area. The work is being carried out by Sorigué in a joint venture with Depuración de Aguas del Mediterráneo (DAM) and SAV for the Consorci Besòs Tordera.