LIFE CYCLE ASSESSMENT OF INTENSIVE / DECENTRALIZED RENEWAL MEASURES FOR UPDATE OF SEWERAGE FACILITIES UNDER POPULATION DECLINE －FOR AREAS DOTTED WITH SMALL FACILITIES－

Abstract

 In this study, in the Tajima area of Hyogo Prefecture, the consolidation of sewage treatment facilities were classified into sewage intensive treatment type by conversion of abolished facilities to relay facilities and sewage dispersion treatment type by transfer to municipal installation type public septic tanks, classified them into two cases and compared and evaluated using three evaluation indicators of cost, greenhouse gas emissions (hereinafter "GHG emissions"), and energy consumption. For each update case, two cases in which the time of renewal is a normal update type and an early update type, including 4 cases that are combined them and a current case that maintains/renews the current number of facilities as a standard, five updated cases were targeted. Evaluation result, sewage dispersion treatment/early update type was shown that the initial cost was 6.8%, the running cost was 7.4%, and the energy consumption was reduced by 4.1% from 2020 to 2050 compared with the current status case.