In a context of climate emergency and growing water deficit, the DECIDEIX project has been launched with the aim of developing planning tools for the safe use of water reuse models. Within this framework, the project will validate the safety and feasibility of implementing a pilot based on Direct Potable Reuse (DPR). This model consists of applying additional treatments to reclaimed water so that it becomes suitable for potable use, without the need for prior passage through rivers or aquifers. It is a practice already regulated or in the process of regulation in regions such as California, Singapore, Australia, South Africa, and Chile, but still not considered in European legislation.

DECIDEIX is an innovative project, pioneering in Europe, led by the technology center Eurecat, with the collaboration of Aigües de Barcelona, the Catalan Water Partnership (CWP), the Catalan Institute for Water Research (ICRA), the Polytechnic University of Catalonia (UPC), and Cetaqua.

The project’s kick-off meeting was held at Eurecat’s headquarters in Manresa. DECIDEIX is co-financed by the Catalan Water Agency (ACA) through its R&D&I grants program dedicated to the circular economy and water reuse.

In the coming months, construction will begin on the pilot at the Gavà wastewater treatment plant, along with the expansion of the Decision Support System (DSS) developed in the previous SUGGEREIX project (funded by ACA in its 2018 R&D&I call). This expansion will include direct and indirect potable uses, thus supporting Catalonia’s water reuse strategies and the creation of an international network of reuse experts.

The metropolitan water deficit could reach 130 hm³ by 2027 if urgent action is not taken. During the recent drought episode, reclaimed water from the Baix Llobregat Water Reclamation Plant was pumped upstream into the Llobregat River, where it was added as pre-potable water to the river flow, allowing the Sant Joan Despí drinking water plant to capture it downstream. This was the first case of Indirect Potable Reuse (IPR) in Europe, and it has proven to be a viable and sustainable solution to ensure water resilience in the Barcelona metropolitan area.

With a duration of 31 months, DECIDEIX represents a step forward from the previous experience of the SUGGEREIX project, carried out with the same partners. That initiative was designed to facilitate access to information on reclaimed water resources in Catalonia and to support decision-making related to their management.

The pilot’s conclusions will provide scientific and methodological evidence to assess, in the future, the regulation of Direct Potable Reuse at the regional or national level, and will contribute to strengthening the safety and sustainability of water resources in the metropolitan area.