Transition of water demand and treatment plant overcapacity: a case study of the Seoul Metropolitan City, Korea

摘要

This study deals with the overcapacity problem of water treatment plants in Korea, and mainlyndiscusses status, causes, and engineering options. To this end, we first statistically analyze thenrecent trend of demand, revealing that the demands of small- and mid-size systems are stillnincreasing while that of large-size systems is now decreasing. Since the existing approach tonplan capacity implicitly assumes that demand will increase at a regular rate, we estimate excessncapacities and system utilizations of large-size systems. From these results it is found that thenlarge-size systems are suffering from serious overcapacity, thus necessitating that engineersnmake very difficult decisions given that systems are still expanding the capacities of plants duento a lack of awareness of the current demand trend. For other systems where there is a betternunderstanding of the transition of demand, planners have ceased to expand plants or havenclosed down relatively old plants in efforts to reduce O&M costs. To address this problem, quicknrecognition of the transition of demand is being highlighted by the concepts of integratednresources management and cybernetics. Therefore, we examined how quickly the new trendnof the Seoul case could be precisely recognized and appropriately addressed. Using the Bayesiannparameter estimation method, we found that a new trend can be recognized six years after thentransition of demand.