EVAS – a practical tool to assess the sustainability of small wastewater treatment systems in low and lower-middle-income countries

Claudia Cossio, a former PhD student affiliated with the group, has published an article regarding the development and application of an Excel-based tool to holistically evaluate the sustainability of existing wastewater treatment plants  in low and middle income countries. Many small wastewater treatment systems (WWTSs) in low and lower-middle income countries face challenges to achieve optimal performance and acceptable levels of sustainability. In order to provide guidance for operation of these systems, Claudia and her colleagues developed a practical tool to diagnose the actual status of WWTSs and identify weak areas for further improvement.

The article is available Open Access – https://doi.org/10.1016/j.scitotenv.2020.140938

The Excel tool is available on the Chalmers website – https://research.chalmers.se/en/publication/516714

Abstract: Small wastewater treatment systems (WWTSs) in low and lower-middle income countries still face challenges to achieve optimal performance and acceptable levels of sustainability. Thus, a practical tool, easy to apply by locals, to diagnose the actual status of WWTSs is required in order to identify weak areas for further improvement. This study presents a sustainability assessment tool, EVAS (EVAluación de Sostenibilidad: EVAluation of Sustainability), for small WWTSs in low and lower-middle income countries. The EVAS tool is developed based on a set of contextualized sustainability indicators and sub-indicators in five dimensions (technical, environmental, social, economic, institutional). Each indicator or sub-indicator is broken down into factors, each associated with specific targets to fulfil, and scored using a traffic light scale (0 to 4) indicating unsustainable-low-medium to high levels of sustainability. The tool was developed taking into consideration that local data may sometimes be incomplete and encourages the collection and monitoring of relevant data. The assessment results support local managers or other stakeholders responsible for wastewater management with the identification of weaknesses that need to be addressed. The tool was tested using two case studies involving WWTSs in Bolivia. One WWTS received a medium sustainability rating, whereas the other system received a low sustainability rating, which indicates that several improvements are required in all sustainability dimensions. Stakeholders in the case studies found the tool useful, and suggested ways in which it could be further improved. It is expected that the application of this tool can contribute to raising the sustainability level of small WWTSs in low and lower-middle-income countries.

Cossio, C., McConville, J. R., Mattsson, A., Mercado, A., & Norrman, J. (2020). EVAS-a practical tool to assess the sustainability of small wastewater treatment systems in low and lower-middle-income countriesScience of The Total Environment, 140938.

Contact: Jennifer McConville

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