A sustainability assessment of rural sanitation systems in the pantanal (Brazil): a multi-criteria approach based on analytic hierarchy process (AHP)

Abstract

Aligned with the Sustainable Development Goals ensuring universal access to water, sanitation, and hygiene (WASH) services, this study highlights the importance of prioritizing rural communities. Addressing the global sanitation challenge demands solutions that balance environmental, economic, and social dimensions, often involving trade-offs that require structured decision-making approaches. The sustainability assessment was applied in a riverine community with limited water and sanitation infrastructure located in the Baía Negra Environmental Protection Area, Pantanal, Brazil, a region of high ecological sensitivity. This research introduces a two-stage model combining the Analytic Hierarchy Process (AHP) with pairwise comparisons to create an aggregated index which was applied for evaluating four sanitation scenarios aiming at toilet wastewater (1A) Baseline scenario (rudimentary septic tank system) (1B) Compostable Dry Toilet + Urine Storage Tank (1C) Evapotranspiration Tank + Male Urine Storage Tank, and (1D) Evapotranspiration Tank. The model employs a three-level decision hierarchy: first, assessing the relative importance of sustainability dimensions; second, ranking indicators within each dimension; and third, applying these to the four scenarios. In the social dimension, input was collected from experts and members of the riverine community, prioritizing five criteria and yielding 18 indicators. The economic and environmental dimensions were evaluated by specialists, with five indicators each. Results showed that Climate Change (33%) and Water Consumption (22%) were the most influential environmental indicators, while in the economic dimension, the Benefit-Cost Ratio (26.8%) and OPEX (23.1%) stood out. In terms of the social dimension, Water Treatment Practices and Existing Artisanal Production Activity were the highest weighted social indicators, both at 9.25%. Applying these weights across the four scenarios, Scenario 1C emerged with the highest overall score (0.34), demonstrating a balance across environmental, economic, and social aspects. This scenario also achieved the highest environmental (0.35) and economic (0.41) scores, while maintaining a competitive social score (0.27). Its strengths included nutrient recovery potential, community receptiveness to water safety practices, and local economic opportunity through nutrient recovery. The integration of urine recycling technologies in sanitation planning contributes to circular economic principles, reduces environmental impact, and enhances agricultural productivity. Overall, this study demonstrates the value of a structured, participatory multi-criteria approach to support sustainable sanitation decision-making in ecologically sensitive and resource-constrained rural contexts.