Life cycle sustainability assessment of asset management plans for municipal wastewater systems

Abstract

Municipal governments have the responsibility to provide safe drinking water and handle polluted water to protect their citizen’s health and safety. Maintaining water infrastructure systems, including wastewater collection pipes and wastewater treatment plants, is essential to sustain these vital services. To date, all municipalities in Ontario have developed an asset management plan to coordinate capital and operational activities required for sustaining their water infrastructure. (Ontario Ministry of Infrastructure 2017b). While this is great progress, significant differences exist among municipalities in terms of the methodology and level of completeness used in developing their asset-management plans (Ontario Ministry of Infrastructure 2017a). In this research, a novel sustainability assessment framework is proposed and demonstrated as part of the solution to establish a complete model framework for sustainable asset management planning. A system-dynamic based sustainability-assessment tool is adapted to evaluate the impact of population growth and urban development on wastewater asset-management planning decisions. The importance of system boundary definition in the proposed framework is demonstrated by evaluating the sustainability impact of strategic decisions in asset management planning for a case study exploring a wastewater collection system. In doing that, a novel system-dynamic model for wastewater-collection and wastewater-treatment plant systems are developed, and the interactions between these two assets are graphically illustrated. The results highlight the significance of coordinating asset management plans of neighboring infrastructure in achieving progress toward sustainable asset-management planning. It is hoped that the application of the proposed framework can help decision makers in municipalities to comply with existing and changing regulatory policies and requirements and to develop socially acceptable, environmentally friendly and financially viable asset-management plans.