Determining the Baseline in Wastewater Management – Necessary but Bypassed Too Often

  • 2018/06/14     Dresden, Germany

    Image: Defne Altiok/UNU-FLORES

    By Cornel Dick, Intern, Communications and Advocacy

    ­­­­More than 2,200 cubic kilometres of wastewater are being annually released into the environment by humankind worldwide (WWAP 2017). Around 80 per cent of that wastewater gets released untreated. Whereas high-income countries treat about 70 per cent of the wastewater they produce, in low-income and lower middle-income countries this rate can drop down to between 8 and 28 per cent, according to the same report.

    Especially in Latin America this is a severe issue: the rapid urbanisation in the last decades of the 20th century diverted the focus of the authorities to just secure sufficient water supplies – but left the question of large-scale wastewater treatment unaddressed.

    Moreover, it is the small to mid-sized cities (around 1 million inhabitants) that are currently experiencing significant population growth in the region and the conventionally centralised, large-scale infrastructure projects have been yielding poor results. Thus, successful solutions have to be much more tailor-made to the local conditions and inclusive regarding local stakeholders.

    This was the starting point of Lucia Benavides’ lecture “Sustainability of Wastewater Systems: Current and Future Perspectives” on 28 May 2018 at UNU-FLORES as part of the Nexus Seminar Series. In her lecture, Benavides – consultant at UNU-FLORES’s Water Resources Management Unit – presents the research framework and current state of the project “Resource Recovery from Wastewater in the Americas – Assessing the Water-Soil-Waste Nexus” also referred to as SludgeTec.

    The SludgeTec project seeks to develop a method to deeply understand current problems, and design locally relevant solutions for wastewater management. The project focuses on two pilot sites: Lake Atitlán (Guatemala) and Tepeji del Río (Mexico).

    The SludgeTec project is facing significant challenges at the pilot sites, though. The local environment reporting standards are poor. Where there is information, it is not centrally maintained but scattered among many knowledge bearers. Additionally, no basic guidelines on how to deal with wastewater locally, is at hand. Ultimately, a top-down approach with little stakeholder participation is the dominant experience of wastewater management in the area.

    Image: Claudia Matthias/UNU-FLORES

    So, the question is: what does a research framework look like, which is locally effective in addressing the multiple issues of sustainability while assuring broad stakeholder participation? In her presentation, Lucia Benavides makes the case for setting up a guiding baseline description. This might seem redundant, but Benavides points out, that it is not at all common practice in the region, to start projects with a comprehensive and systemic understanding of the problem in question.

    Building up a baseline means bringing together all the compartmentalised knowledge bearers and stakeholders of the region, to overcome data gaps and to be able to understand the multiple components of the relevant system, as well as their complex interactions.


    Benavides emphasises SludgeTec’s strong adherence to holistic and systems thinking. For developing the baseline this means addressing the question of which different scales and layers of reality should be integrated into the system model.

    It is possible to use many different scales in the construction of a system model – for instance, the scale of the watershed or the municipal boundaries. One problem is that administrative and natural scales and boundaries seldom coincide. Thus, applying a multiscale approach enables for the accounting of the whole complexity of the system and allows comparisons between different points of view.

    The same applies to the multiple ‘layers of reality’ that the baseline system model needs to keep in mind: considering not only the technical and biophysical components of the system, but also the stakeholder as well as the policy layer. Combining the multiscale and the multilayer approaches, thereby, allows for an integrated account.

    Finally, Benavides presented the findings of the project so far: whereas around 40 per cent of the wastewater is being channelled to the wastewater treatment plant at the pilot site, the efficiency of the treatment, however, is supposedly way below standards (AMSCLAE 2015 as cited in Ferráns et al. 2018). Other findings include that, though there is (scattered) data and high motivation on the stakeholders’ side to participate in projects,  the actual problem is not necessarily technical in nature. There is an issue of the social and policy dimension, with regard to the empowerment of the local community. Certain stakeholders are being excluded from the often top-down decision-making process.

    Even though queries came measured at first, the decisive question was asked after the presentation: what does all of this have to do with the Nexus Approach? Benavides responded that nexus thinking lies in the foundations of wastewater treatment. Indeed, on the one hand wastewater treatment physically affects all three different components of the Water-Soil-Waste Nexus. On the other hand, treating wastewater has important implications for other interlinkages such as water quality and food production – considering groundwater pollution due to eutrophication, for instance (WWAP 2017).


    AMSCLAE. 2015. “Informe de Muestreo de las plantas de tratamiento de aguas residuales de la cuenca del Lago de Atitlan 2012–2015”. Guatemala: AMSCLAE.

    Ferráns, Laura, Serena Caucci, Jorge Cifuentes, Tamara Avellán, Christina Dornack, and Hiroshan Hettiarachchi. 2018. Wastewater Management in the Basin of Lake Atitlan: A Background Study. Working Paper. Dresden: United Nations University Institute for Integrated Management of Material Fluxes and of Resources (UNU-FLORES).

    WWAP (United Nations World Water Assessment Programme). 2017. The United Nations World Water Development Report 2017. Wastewater: The Untapped Resource. Paris: UNESCO.