Analysis of probabilistic maintenance cost variation ranges through surveys of maintenance cycles/maintenance cost ratios for wastewater treatment plants

Abstract

The purpose of this study is to analysis of probabilistic maintenance cost Variation ranges through surveys of maintenance cycles/maintenance cost ratios for wastewater treatment plants To achieve this purpose, seven plants of similar capacity were selected and surveys on its maintenance cost were conducted with its operation managers. The maintenance cycles and cost ratios were carried out through the surveys and applied to determine expected maintenance costs based on a forty-year operating period. A probabilistic analysis on the maintenance costs was carried out to derive its variations and sensitivity. The results of this study are as follows: The total maintenance costs have an average of 3,358 million KRW and vary from a minimum of 2,900 million KRW to a maximum of 3,925 million KRW. In sensitivity analysis, the structure with the most sensitive maintenance costs is grit chamber followed by disinfection tank, aeration tank, first and final sedimentation basin, and flow equalization tank in descending order of sensitivity.