• Thirty-four professionals from 12 countries from North Africa, the Middle East and Europe attended the Advanced Course on Wastewater Reuse for Agriculture, held at CIHEAM Zaragoza, Spain, from 20 to 25 October 2025.
• The course was jointly organised by the International Centre for Advanced Mediterranean Agronomic Studies (CIHEAM), through the Mediterranean Agronomic Institute of Zaragoza (CIHEAM Zaragoza), and the International Center for Agricultural Research in the Dry Areas (ICARDA), with the collaboration of the Regional Office for the Near East and North Africa of the Food and Agriculture Organization of the United Nations (FAO), the Spanish Agency for International Development Cooperation (AECID), and the International Water Management Institute (IWMI).

Non-conventional water resource development and use for agriculture in arid and semiarid regions is of utmost importance in responding to the increasing food demand of the rapidly and ever-growing population. These regions suffer from growing water scarcity, water quality deterioration, and the uncertainties associated with climate change. To overcome this situation, the safe use of treated wastewater should be largely adopted in places where the available water for agriculture is decreasing.

The programme was delivered by experts from research centres (CEBAS-CSIC; INRAE) and universities (Univ. Seville, Univ. Jordan), from different countries and international organisations (FAO, IMWI), and from the Italian National Association of the Agricultural Water Board. The course attracted 34 experts - 21 participating in person from Algeria, Egypt, Italy, Jordan, Lebanon, Morocco, Palestine, Spain, Tunisia, and Türkiye, and 13 who followed the course online from Chile, Egypt, Italy, Libya, Morocco, Palestine, Spain, and Türkiye.

The challenge lies in equipping professionals involved in the management and use of non-conventional water resources with the most efficient and cost-effective treatment technologies, together with protocols, guidelines and case studies to support optimal use of these valuable resources. This advanced course provided an overview into regulatory frameworks as well as legal, environmental, and socioeconomic constraints to ensure the safe use of non-conventional water resources. It also presented actionable recommendations and illustrative examples to promote social acceptance and inform effective re-use policies.

Over the course of the six-day programme, theoretical sessions were combined with practical exercises and case studies. The practical exercises addressed water reuse risk management for agricultural irrigation schemes, and technical solutions and agricultural good practices in different socioeconomic contexts. Participants were also guided through a play-to-learn exercise in participatory processes for wastewater reuse. Finally, face-to-face course participants had the opportunity to visit a wastewater treatment plant in Vitoria and a nearby irrigation area using wastewater.

The programme covered several key areas, starting with wastewater treatments, emphasising the importance of advanced purification methods and sustainable reuse. It then explored risk assessments, highlighting how evaluating potential hazards is essential to ensure public health and environmental safety. The section on field implementations focused on practical applications, demonstrating how theoretical knowledge can be effectively applied to real-life projects.

Participants also examined the institutional framework and policy instruments governing wastewater management, gaining a clearer understanding of how regulations shape national and regional strategies. The course concluded with a comparative analysis of experiences and regulations in different countries, which provided valuable insights into diverse approaches and best practices across the Mediterranean region.

Several general conclusions emerged from the discussions held during the course: It is essential to promote the use of treated and reclaimed water in Mediterranean agriculture as a sustainable resource; achieving a balance between safety and economic feasibility is crucial for long-term viability; sharing experiences among countries is vital, since similar challenges often require tailored yet harmonised solutions; and establishing a common Mediterranean framework for regulations and risk assessments would help to align efforts and improve regional collaboration.

One of the best outcomes of the course was the excellent interaction and cooperation among participants. The strong relationships built within the group have opened the door to future collaborations, fostering a shared commitment to sustainable water management in the Mediterranean area.