Selection of sewer pipe materials : comparing two lifecycle approaches

Sewer systems are subjected to deterioration due to aging, aggressive environmental factors, increased demand, inadequate design, improper operation and maintenance activities. As a result their current-state and overall long-term performance are affected, which often requires costly and extensive maintenance, repair and rehabilitation. Therefore, it becomes a challenging task for the decision-makers to make a decision that improves design, construction, operation and maintenance activities. The main aim of this study is to evaluate different materials of sewer pipes (i.e., concrete, polyvinyl chloride, vitrified clay and ductile iron) and identify sustainable solutions using both an emergy-based lifecycle approach and a traditional lifecycle approach. Emergy method converts all forms of lifecycle inflows (such as energy, raw resources, labour, money, services and information) to an equivalent form of solar energy, named solar emergy joule (sej), which does not require any multi -criteria method to aggregate non-commensurate values. On the other hand, in traditional lifecycle approach, analytical hierarchical process method has been used to integrate environmental and economic impacts of different pipes. Analysis based on emergy-based LCA approach is useful and more credible, as it measures the contribution of environmental and economic impacts in a common unit which removes the multi-criteria dilemma. The analysis results demonstrate that PVC pipe is the most sustainable option from both environmental and economic points of view and can guarantee a more sustainable sewer system.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat