Water sanitation, key to people's health

Population growth, rapid urbanization, and the need for more resilient infrastructure in the face of climate change are some of the global challenges that highlight the importance of commemorating World Toilet Day every November 19th. This day, promoted by the United Nations, aims to raise awareness about a service essential for health and the environment. The lack of adequate sanitation causes environmental pollution from wastewater and poses a serious threat to almost half of the world's population, who still lack access to these basic services, according to data collected in 2025 by the World Health Organization (WHO) and UNICEF. In Catalonia, the combination of prolonged droughts and torrential rains—increasingly frequent phenomena due to global warming—tests the capacity and resilience of infrastructure related to the water cycle. Although Spain has high standards in urban water services, three key challenges remain: wastewater collection and treatment, regeneration, and investment in facilities prepared to face the climate emergency.

Commitment to ecological transformation

To address these challenges, Veolia, a global leader in environmental services for water, energy, and waste, applies its technical and operational expertise to the efficient management of water resources and sanitation networks. The company promotes projects based on sustainability and the circular economy, often through public-private partnerships, with the aim of contributing to the ecological transformation of cities and regions.

The ecofactory model

Across Spain, Veolia supplies water to 13.5 million people in over 1,100 municipalities and leads the management of wastewater treatment services, treating more than 25% of the wastewater generated in the country. 14% of this water is reused, a milestone explained by the ecofactory model, which transforms traditional wastewater treatment plants into green and self-sufficient infrastructures designed to close the water and resource cycle. This model is based on four pillars: regenerating and reusing water for urban, agricultural, or industrial uses; valorizing waste by converting it into new resources; reducing energy consumption and maximizing green energy production; and minimizing the environmental impact of the facilities through their renaturalization. The Baix Llobregat example

In Catalonia, the Baix Llobregat Ecofactory, operated by Aigües de Barcelona, ​​is a prime example of this model. The treated reclaimed water is used to maintain the ecological flow of the Llobregat River and to recharge the aquifer of the Sant Vicenç dels Horts reservoirs. It also acts as a barrier against saltwater intrusion along the Barcelona and El Prat de Llobregat coastline, thus protecting the water quality of the Llobregat Delta, a vital underground reserve for the metropolitan area. Regarding wastewater recovery, 100% of the more than 230,000 tons of sludge generated in 2024 at the wastewater treatment plants managed by Aigües de Barcelona were recovered through composting or direct agricultural application, resulting in emissions savings of nearly 15,000 tons.₂A key initiative in this area is the new sludge reception and rehydration platform at the same ecofactory, which will allow the treatment of more than 40,000 tons annually from the Besòs wastewater treatment plant and the utilization of some of its energy potential in the form of biogas for electricity generation.

Innovation and digitalization of the water cycle

Among the initiatives driving the transformation of ecofactories, the RESSONA project stands out, funded by the PERTE program for the digitalization of the urban water cycle. The project, also developed by Aigües de Barcelona, ​​allows for the quantification and characterization of discharges into metropolitan sanitation systems during rainfall events. With an investment of over €35 million, RESSONA is subsidized by the Ministry for Ecological Transition and the Demographic Challenge and co-financed by the Barcelona Metropolitan Area and the Catalan Water Agency. Last September, the ministry recognized the initiative for its innovative nature and for improving the resilience and sustainability of the water cycle during a time of structural water emergency. Sanitation as health surveillance

Sanitation also plays an essential role in epidemiological surveillance. Wastewater analysis is now a key tool for anticipating health risks, activating preventive measures, and increasing the effectiveness of public health responses. Within the framework of the EU4Health program, the European Health and Digital Executive Agency (HaDEA) launched a project in 2025 to optimize the monitoring of pathogens and contaminants in wastewater at a European scale, with the aim of creating an early warning system for future pandemics. Veolia is the only company in the sector participating in this initiative, analyzing up to 500 wastewater samples collected in European cities through its laboratories in Spain. Each sample undergoes more than 500 comprehensive analyses to detect contaminants, viruses, bacteria, and pharmaceutical residues. The project, developed jointly with the Spanish National Research Council (CSIC), Veolia's Water Technology Center (Cetaqua), and the University of Santiago de Compostela, builds on more than a decade of experience in water monitoring in cities such as Barcelona, ​​Madrid, and Seville.

Commitment to health and the environment

In a constantly changing world, Veolia reaffirms its commitment to environmental safety and the protection of public health through tangible and effective actions. These initiatives contribute to ensuring a healthier environment, sustainable resource management, and a better quality of life for individuals and communities.