Study on Simulation Model and Evaluation for Sewerage System Sustainability: Analysis on Statistical Data and Proposal of Sewerage Sustainability Index

Abstract

Due to population decrease and society aging, per capita sewerage expenditure is increasing whereas total municipality income is decreasing, which results in poor sustainability of sewerage projects in Japan. For its quantitative analysis, a financial model was developed in which “sewerage sustainability index” was defined as a project balance per municipality income. With this model, sustainability of 86 sewerage projects were evaluated, and sensitivity analysis was carried out for 4 municipalities to compare effects of operating conditions on the index. This analytical methodology can be used in policy making for the future of sewerage projects.