During the X Water Dialogues Latin America and the Caribbean – Spain, held on October 17 and 18, 2024, in Madrid, ECLAC presented progress and studies on the implementation of the circular economy in wastewater treatment. Discussions focused on methane and electricity recovery in treatment plants, addressing the technical and regulatory challenges faced by the region.

At the X Water Dialogues Latin America and the Caribbean – Spain, organized by CAF in Madrid, innovative solutions were discussed to tackle the challenges of climate change in water management in urban areas. During the event, Silvia Saravia Matus, Economic Affairs Officer of ECLAC, presented evidence on the opportunities of the circular economy in wastewater treatment in Latin America and the Caribbean, focusing on methane recovery and electricity generation in medium and small-scale plants.

For cities with populations between 500,000 and 2 million inhabitants, a sample of 75 wastewater treatment plants located in 66 municipalities across five Latin American and Caribbean countries (Mexico, Costa Rica, Colombia, Peru, and the Plurinational State of Bolivia) was analyzed. To install methane recovery infrastructure in this selection of 75 medium-sized plants, an investment of $251 million is required. If the electricity produced is used for self-consumption, the wastewater treatment plants could achieve annual savings of up to $46 million. This results in a benefit-cost ratio of 1.36.

In addition to reducing operational costs of the plants by approximately 40%, methane emissions would also be reduced by 88%, using the current situation as the baseline. You can access the study here.

This year, ECLAC published a second document titled Technical and Financial Roadmap for Methane and Nutrient Recovery from Wastewater in Latin America and the Caribbean, where the same analysis was conducted in even smaller municipalities, with populations ranging from 10,000 to 40,000 inhabitants, which equates to plants with capacities between 30 to 220 liters per second. The results were also promising in select localities of Mexico and El Salvador, where prefeasibility studies were conducted on-site. Transforming 7 treatment plants of this scale requires an investment of 5 million USD, which can be recovered in 5.5 years, ensuring savings of 1.35 million USD annually from reduced electricity consumption. You can access the study here.

Within the framework of these discussions, questions were raised about the necessary conditions to implement this approach effectively, emphasizing the need for adequate public policies and regulatory frameworks. It was highlighted that, to facilitate the adoption of these technologies, it is essential to strengthen technical and operational capacities at the local level and to adjust regulations that allow the reuse of treated water and the commercialization of energy generated by the plants.

Specific examples of initiatives in the region were also addressed. In El Salvador, ECLAC is supporting the transformation of a treatment plant in Metapán, in collaboration with the Salvadoran Water Authority. Similarly, in Colombia, ECLAC is working with the Commission for Drinking Water and Sanitation Regulation and the Ministry of Energy and Mines to analyze 100 treatment plants, with the goal of promoting methane capture and recovery for electricity generation.

At the end of the event, participants agreed that the circular economy is key to ensuring water resilience in cities, especially in the face of the challenges posed by climate change, and that it is necessary to strengthen technical, operational, political, and prospective capacities to ensure its adoption.