Economic and Social Evaluation of Decentralized Sanitation Systems

Decentralized sewage treatment systems are a viable solution for universal basic sanitation, providing technologies that meet discharge and reuse standards while benefiting the environment. This study applied Social Life Cycle Assessment (S-LCA) and Life Cycle Cost Analysis (LCC) to evaluate nine treatment scenarios for single-family homes in peri-urban Brazil. Scenarios included rudimentary septic tanks, septic tanks with soakaway, and source-separation technologies like
evapotranspiration tanks (TEvap), compostable dry toilets, constructed wetlands for greywater, and urine storage tanks. Indicators assessed included economic factors (CAPEX, OPEX, TC, NPV) and social factors (health, monetization, living conditions, and development). The TEvap system for blackwater with greywater reuse (EvaTAC) ranked highest in economic and social sustainability, while rudimentary septic tanks performed poorly socially but moderately economically due to lower costs. These findings provide valuable insights into sustainable decentralized sewage technologies for peri-urban areas in Brazil, supporting informed decision-making to improve economic and social outcomes.