Sustainability assessment of urban and peri-urban sanitation systems relevant in the Bolivian context

This report presents a multi-criteria sustainability assessment method for urban and peri-urban sanitation systems, applied as a case study in Montero, Bolivia. It evaluates four system types—conventional sewers, condominial sewers, septic tanks, and urine-diverting dry toilets—across five dimensions: health and hygiene, environmental, social, economic, and technical/institutional sustainability. The study compares existing systems with 'optimized' versions and discusses the role of technological innovations in improving public health and environmental protection.

• The report introduces a technology-neutral sustainability assessment method based on multi-criteria analysis (MCA) and stakeholder engagement. The process consists of seven steps: identifying system boundaries, defining criteria and indicators, choosing systems, assigning weights, performing the assessment, conducting sensitivity analysis, and gathering stakeholder feedback.
• In the Montero case study, System 4 (Urine-diverting dry toilets - UDDTs) demonstrated the highest overall sustainability among existing systems, particularly scoring high in health and hygiene, water use, and vulnerability to water scarcity.
• System 1 (conventional gravity-fed sewers) was found to be the least sustainable in terms of household affordability, economic sustainability, and vulnerability to flooding and water scarcity.
• None of the four sanitation systems as they currently function in Montero remove nutrients (total nitrogen and total phosphorus) and biological oxygen demand (BOD5) to a satisfactory level.
• Optimizing systems through low-cost interventions, such as the use of personal protection equipment (PPE) and improved operation and maintenance (O&M) routines, significantly increases health and hygiene sustainability for Systems 1, 2, and 3.
• Conventional sewered systems (Systems 1 and 2) exhibit inherent technical inflexibility, making it difficult to improve their scores for vulnerability to flooding, water scarcity, and household affordability through optimization.
• Financial sustainability for sanitation utilities requires covering both capital expenditure (CAPEX) and operating expenses (OPEX) through 'the four Ts': tariffs, taxes, transfers, and trade.
• System 1 is heavily subsidized compared to other system types, and the report argues that all sanitation options should have access to similar financing mechanisms and subsidy levels to ensure affordability for low-income families.
• Technological innovations, such as Up-flow anaerobic sludge blanket (UASB) reactors and chemical precipitation for System 1, or submerged aerated filters (SAF) for System 2, can improve effluent quality but generally increase technical complexity and reduce economic sustainability.

APA

Kvarnström, E., Ahlström, M., Andersson, K., & Heredia, G. (2023). Sustainability assessment of urban and peri-urban sanitation systems relevant in the Bolivian context. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2023/01/montero-sanitation-sei2023.003.pdf

Chicago

Kvarnström, Elisabeth, Markus Ahlström, Kim Andersson, and Gustavo Heredia. Sustainability assessment of urban and peri-urban sanitation systems relevant in the Bolivian context. Stockholm Environment Institute, 2023. https://www.sei.org/wp-content/uploads/2023/01/montero-sanitation-sei2023.003.pdf.

Wikipedia

{{cite report |last1=Kvarnström |first1=Elisabeth |last2=Ahlström |first2=Markus |last3=Andersson |first3=Kim |last4=Heredia |first4=Gustavo |title=Sustainability assessment of urban and peri-urban sanitation systems relevant in the Bolivian context |publisher=Stockholm Environment Institute |date=January 2023 |url=https://www.sei.org/wp-content/uploads/2023/01/montero-sanitation-sei2023.003.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{kvarnstrm2023sustainability, author = {Kvarnström, Elisabeth and Ahlström, Markus and Andersson, Kim and Heredia, Gustavo}, title = {{Sustainability assessment of urban and peri-urban sanitation systems relevant in the Bolivian context}}, institution = {Stockholm Environment Institute}, year = {2023}, month = jan, url = {https://www.sei.org/wp-content/uploads/2023/01/montero-sanitation-sei2023.003.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }