From Waste to Resource: Sustainable Wastewater Management in Latin America

2019•05•01 UNU-FLORES

The United Nations University (UNU) takes an interdisciplinary, cross-cutting approach to research on pressing global problems. UNU generates knowledge to support an evidence-based rethinking of policies by providing decision-makers with fresh perspectives on the most urgent policy issues, proactive analyses of emerging concerns, and sound policy alternatives.

To better highlight UNU’s people, approach, and products, the UNU 2018 Annual Report includes feature articles that provide an example of UNU’s work on three select topics — the following feature on wastewater management, and features on gender digital equality and inclusive economic development.


Fresh water, which balances ecosystems, drives industry, feeds agriculture, and sustains human health, accounts for only 3% of Earth’s water. Today, 3.6 billion people are already affected by water scarcity, and global demand is expected to grow by 40% by 2050. And as water consumption increases, so too will wastewater — 80% of which is currently released untreated into the environment.

Spotlighting this plight at the launch of the Water Action Decade in March 2018, UN Secretary-General António Guterres implored that “we cannot continue to take water for granted and expect to achieve the Sustainable Development Goals. Solutions exist and new technologies are in the pipeline to improve how we manage water…but often these solutions are inaccessible for those who need them most…”

To ensure that solutions to this complex problem are accessible, the United Nations University Institute for Integrated Management of Material Fluxes and of Resources (UNU-FLORES) collaborated with partners in Germany and Latin America on the project Resource Recovery from Wastewater in the Americas — Assessing the Water-Soil-Waste Nexus (otherwise known as SludgeTec).

This partnership between Universidad de San Carlos de Guatemala, Fideicomiso de Infraestructura Ambiental de Los Valles de Hidalgo, Mexico, and Technische Universität Dresden, brought together international experts and local stakeholders to co–design sustainable wastewater treatment and management systems for communities in Guatemala and Mexico.

Challenges for an urbanising region

Filling an 80,000-year-old caldera in the Guatemalan Highlands, Lake Atitlan is renowned as one of the world’s most beautiful freshwater lakes. It is also Central America’s deepest lake and the primary source of water for over 70,000 people living in Panajachel — one of 15 Lake Atitlan municipalities.

Panajachel’s population is 95% indigenous, and 70% live in poverty exacerbated by resource management challenges such as wastewater disposal, deforestation, erosion, and demographic pressure. Discharges of raw and partially treated wastewater from lake communities have had a number of human health impacts, including waterborne disease and skin infections.

“To ensure the health and well-being of their population, small- and medium-sized cities in Latin America and the Caribbean need environmentally, socially, and economically sustainable wastewater management solutions.” Tamara Avellán UNU-FLORES Academic Officer

Further north, in Mexico, the Requena dam near Tepeji provides drinking water for 87,000 people, almost half of whom live in poverty. This region is also troubled by resource management challenges, in particular water scarcity.

For more than 100 years, Tepeji farmers have alleviated agricultural water shortages by using wastewater for irrigation. While their resourcefulness has helped mitigate water scarcity and improve their crop yields, the use of insufficiently treated wastewater has had a number of negative environmental, sanitary, and social impacts such as cholera outbreaks and accumulation of heavy metals in the soil.

The challenges that these two municipalities face at the intersections of water, soil, and waste are not unique. Throughout Latin America and the Caribbean, 50% of the population lives in small- and medium-sized cities where similar wastewater problems impact their well–being and prosperity. And due to the region’s rapid urbanisation, this percentage continues to grow.

Research with and for communities

Latin American and Caribbean countries urgently need to invest in sustainable, locally-appropriate options
for wastewater treatment if they intend to achieve the Sustainable Development Goals (SDGs). But as with many global SDG efforts over the past four years, early progress on water challenges has been hindered by a lack of baseline data and shared knowledge.

As part of its “Foundations for Action”, the 2018 UN High Level Panel on Water stressed that for effective water management, “stakeholders need to understand the quantity, quality, distribution, use, and risks of the water they have, and therefore need to invest in water-related data as well as the systems to share, analyse, and take decisions with this data”.

Acknowledging this need from the outset, the SludgeTec team used participatory methods to engage researchers, practitioners, municipal decision-makers, and local communities in hands-on knowledge-sharing activities. This gave participants the opportunity to contribute, regardless of their cultural and professional backgrounds or their language abilities. This was particularly essential to give equal voice to the communities’ indigenous populations.

“Sustainable solutions depend on participatory processes that provide capacity development opportunities for stakeholders and local communities and involve them in all project phases from assessment to implementation.” Angela Hahn, UNU–FLORES Research Associate

A mix of roundtable discussions and transregional workshops facilitated vital exchange among stakeholders in Guatemala and Mexico, enabling communities to learn from each other’s unique wastewater challenges and build a common pool of knowledge.

Wastewater management has a direct impact on the availability and quality of resources such as water and soil. To find solutions that consider these interdependencies, SludgeTec researchers employed a “Nexus Approach” that focuses on understanding resource flows across different scales and between different points in a cycle. Using this methodology reveals potential benefits and implications for other sectors and resources, and related SDGs such as health (SDG 3) and food production (SDG 2).

Instead of just looking at the individual resources, the Nexus Approach considers the functioning, productivity, and management of the economic and social dimensions of a complex system.

A framework for sustainable solutions

Fifteen months of collaboration with communities guided the SludgeTec team to develop and apply a transdisciplinary framework of methods. The resulting recommendations may allow local stakeholders to take ownership of their solution process and fix the technical issues of the treatment plant. This could lead to innovative solutions for overcoming unsustainable wastewater situations by establishing, for example, a citizen observatory for community–based monitoring systems, and regular and open neighbourhood discussion forums, as was recommended by stakeholders in Mexico.

“We have been working with UNU–FLORES on this project since 2016 to improve sanitary conditions, waste disposal and wastewater treatment technologies, and the sustainability of managing pollutants around Lake Atitlan. SludgeTec alone will not solve the lake’s problems, but it is an integral part of improving the health conditions of about 300,000 people in villages around the lake and essential for conserving our beautiful Lake Atitlan,” said Jorge Ivan Cifuentes of the Department of Engineering and Nanotechnology of Materials at the University of San Carlos of Guatemala.

“Sustainable solutions for wastewater management include resource recovery such as the use of treated wastewater for irrigation, or stabilised sludge as soil amendment.” Serena Caucci, UNU–FLORES Senior Research Associate

From enhancing environmental performance of treatment plants, and ways to improve data collection, to strengthening partnerships and improving governance strategies, the SludgeTec framework can be used to guide municipal governments towards targeted system sustainability.

Improvements can be as simple as stopping solid waste burial on the premises of the treatment plant or establishing a Facebook page to inform the community about issues related to water and wastewater. Other initiatives are more complex, for example, planning health and safety measures for facility workers or establishing regular meetings for exchange and decision-making between key stakeholders and those who have been less likely to be included, such as indigenous community organisations.

In many ways, the crux of achieving the SDGs is their interdependence. As environmental resources such as water, soil, and waste become increasingly threatened by the impacts of climate change, demographic shifts, and socio-economic pressure, we must look beyond outdated resource management approaches that ignore this interdependence.

UNU is doing its part through pioneering research like the SludgeTec project. By leveraging innovative methods such as the Nexus Approach, UNU is addressing the needs of developing and emerging economies in the management of environmental resources, and ensuring that vulnerable regions around the world are better equipped with the knowledge and abilities to achieve sustainable development.


For more on UNU’s recent work to help achieve all 17 Sustainable Development Goals, see the UNU 2018 Annual Report.