A system dynamics approach to determine construction waste disposal charge in Hong Kong

Abstract

Extensive research has devoted to facilitating sustainable construction and demolition waste management. Waste disposal charging scheme is an effective tool in fostering waste reduction and minimising environmental burden. However, the determination of waste disposal charging fee was mostly designed for cost recovery at present rather than meeting the future needs. This study develops a generic system structure for determining an optimum waste disposal charging fee for sustainable development and elaborates dynamic relationships between social/economic factors and waste disposal charging fee. A comprehensive system dynamics model was constructed to predict the optimum waste disposal charging fee by integrating quantitative and qualitative factors from the literature and questionnaire survey, which was then validated with the historical data in Hong Kong. The use of this model assesses and projects the structure, interactions of the complex system in waste disposal charges in an integrated and holistic manner. Two sets of policy scenario analysis were conducted for evaluating the effects of the newly modified waste disposal charging fee implemented by the Hong Kong government and identifying an optimum range of waste disposal charging fee. The simulation results indicated that the newly modified waste disposal charging fee is ineffective to achieve construction and demolition waste reduction in the long term. To devise policy strategy for sustainable waste reduction, the optimum increment percentage on original landfill and public fill charging fees should not exceed 250% and 400%, respectively. The proposed model serves as a scientific approach for decision-makers to better design the architecture in the complex system of construction and demolition waste management.