Browsing by Autor "Claudia Cossio"

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EVAS - a practical tool to assess the sustainability of small wastewater treatment systems in low and lower-middle-income countries
(Elsevier BV, 2020) Claudia Cossio; Jennifer McConville; Ann E. Mattsson; Alvaro Mercado; Jenny Norrman
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.
Impact of treatment plant management on human health and ecological risks from wastewater irrigation in developing countries – case studies from Cochabamba, Bolivia
(Taylor & Francis, 2019) Claudia Cossio; Luis Fernando Perez-Mercado; Jenny Norrman; Sahar Dalahmeh; Björn Vinnerås; Alvaro Mercado; Jennifer McConville
Wastewater irrigation is a common practice in developing countries due to water scarcity and increasing demand for food production. However, there are health risks and ecological risks associated with this practice. Small-scale wastewater treatment plants (WWTPs) intend to decrease these risks but still face management challenges. This study assessed how the management status of five small-scale WWTPs in Cochabamba, Bolivia affects health risks associated with consumption of lettuce and ecological risks due to the accumulation of nutrients in the soil for lettuce and maize crops. Risk simulations for three wastewater irrigation scenarios were: raw wastewater, actual effluent and expected effluent. Results showed that weak O&M practices can increase risk outcomes to higher levels than irrigating with raw wastewater. Improving O&M to achieve optimal functioning of small-scale WWTPs can reduce human health risks and ecological risks up to 2 log10 DALY person-1 year-1 and to 2 log10 kg nitrogen ha-1 accumulated in soil, respectively.
Importance of triggers and veto-barriers for the implementation of sanitation in informal peri-urban settlements – The case of Cochabamba, Bolivia
(Public Library of Science, 2018) Ida Helgegren; Sébastien Rauch; Claudia Cossio; Graciela Landaeta; Jennifer McConville
An estimated 2.4 billion people lack access to improved sanitation which has devastating consequences for human health and the environment. Understanding what constitute sanitation demand is crucial for accelerating the spread of improved sanitation. This study aims to understand the adoption mechanisms for improved sanitation. An informal peri-urban settlement in Cochabamba, Bolivia was selected as a case study to understand adoption patterns. Various qualitative methods of data collection and analysis were employed. The findings showed that pour-flush toilets was the only preferred sanitation alternative at the study site. An adoption framework for waterborne toilets was developed based on diffusion of innovation theory. Factors that influence adoption were identified. Some functioned as triggers and initiated adoption, whereas some factors blocked adoption and constituted veto-barriers. Most factors were connected to the individual household situation and its members, but neighborhood development also affected pour-flush adoption. Based on adoption time the residents were divided into the following adoption groups: first adopters, early majority, late majority, laggards and non-adopters. Each adoption group followed its own adoption route with specific characteristics and respective triggers or veto-barriers. We argue that the strong demand for waterborne toilets in peri-urban areas need to be recognized and the developed framework could be used for customizing sanitation improvement programs for certain target groups.
Indicators for sustainability assessment of small-scale wastewater treatment plants in low and lower-middle income countries
(Elsevier BV, 2020) Claudia Cossio; Jenny Norrman; Jennifer McConville; Alvaro Mercado; Sébastien Rauch
Wastewater treatment in low and lower-middle income countries is often limited by lack of local technical expertise, institutional capacity, and financial resources, making it challenging to reach SDG6-target 6.3, i.e. halving the proportion of untreated wastewater. Several studies suggest sets of sustainability indicators for assessing the planning and/or operation of WWTPs. However, existing standard indicators are typically focused on the context of high and upper-middle income countries, whereas low and lower-middle income countries face other types of issues. The development of a contextualized set of relevant and effective sustainability indicators to support the planning and/or operation of small-scale WWTPs in low and lower-middle income countries is crucial. This study develops a contextualized set of sustainability indicators for small-scale wastewater treatment plants in Bolivia, which is classified as a lower-middle income country. Indicators were identified using a literature review combined with empirical studies using focus groups with managers and operators, as well as, workshops with experts. The aim of the focus groups and workshops was to acquire an understanding of the local context and identify relevant sustainability indicators. The practical investigation took place at five sites in Cochabamba, Bolivia. The results suggest that sustainability assessment of WWTPs in low and lower-middle income countries should emphasize the institutional dimension (e.g. Institutional capacity, Interactions, and Information) and the technical dimension (e.g. Sewage network functionality and Expertise) alongside indicators in the social, economic and environmental dimensions.
Wastewater management in small towns – understanding the failure of small treatment plants in Bolivia
(Taylor & Francis, 2017) Claudia Cossio; Jennifer McConville; Sébastien Rauch; Britt‐Marie Wilén; Sahar Dalahmeh; Alvaro Mercado; Ana Malvis Romero
Wastewater management in developing countries is a challenge, especially in small towns with rapid population growth. This study aims at assessing the performance and management of five treatment plants (TPs) in rural areas of Cochabamba, Bolivia. Pollutants' concentrations, wastewater flows, hydraulic and organic loads and hydraulic retention times were determined in three small treatment plants (2000-10,000 population equivalent [p.e.]; flow > 432 m3/d) and two very small treatment plants (<2000 p.e.; flow < 432 m3/d). The performance assessment was based on operational parameters, treatment efficiency and effluent quality. Management data were collected through semi-structured interviews with managers of local water associations. The results support that the poor performance of the TPs is due to lack of operational expertise and financial resources for adequate operation and maintenance (O&M). Additionally, effective treatment was affected by the type of technology used and whether the plant design included plans for O&M with available resources. This study contributes to a better understanding of actual operating conditions of wastewater TPs in small towns, thus providing needed information regarding technology selection, design, implementation and operation.