Roses, Catalonia, Spain – Pilot project exploring purified recycled water treatment for future groundwater augmentation

The Mediterranean region is characterised by the continuous challenge in the management of its limited freshwater resources, which will be exacerbated during the next years/decades as a direct effect of climate change. With this scenario, finding alternative water resources is essential to cover the water demand needed by society.  

In the geographic area managed by Consorci d’Aigües Costa Brava Girona (CACBGi), northeast of Barcelona (Spain), approximately 25 hm³ of used water are discharged into the sea every year. This quantity represents a significant amount that could instead be purified and recycled as an alternative resource. To generate purified water, used water is subjected to a multi-barrier treatment to ensure the necessary quality for injection into drinking water aquifers.  

To study the incorporation of purified water into its supply portfolio for a circular water management in the region, CACBGi has established the AIGUANEIX project, which commenced in 2024. In the AIGUANEIX project, a pilot plant is being constructed, installed, and operated in an Advanced Water Treatment Facility in the domain of CACBGi. The main objectives of the project are to

(i) demonstrate the feasibility of the technical approach, i.e., demonstrating the high water quality that can be achieved;

(ii) generate operational data on a variety of treatment combinations to develop recommendations for future technology selection if going forward to implementation at full-scale;

(iii) showcase state-of-the-art approaches of purified water generation to the professional community and the wider public. 

The pilot plant will include ultrafiltration, reverse osmosis, advanced oxidation, and adsorption on granular activated carbon, besides supplementary processes such as chloramination and remineralisation. These processes can be combined in different ways, such that the pilot plant constitutes a flexible demonstration facility, visible and visitable to everyone. The purified water generated with the pilot plant will be approximately 500 m3/week and operation will commence in 2025. 

During the pilot plant experimentation, it is not foreseen to proceed with the injection of purified water in the aquifer.