Drinking Water Infrastructure Assessment: The National Research Council of Canada Perspective

The essence of infrastructure asset management and decision-making on its renewal/rehabilitation is a trade-off between system performance and cost. System performance criteria for water networks include quality, quantity and reliability, i.e., the water should be safe, with acceptable aesthetics, taste and odour; regular and peak demand (including fire flows) should be met with acceptable pressure and with minimal interruptions. Costs comprise capital investment in system design, installation and renewal, operation and maintenance (energy, materials, labour, monitoring, inspection, testing, repair), and indirect and social costs incurred due to failure (property damage, disruption, illness, etc.). Several challenges need to be overcome in the development of an integrated decision framework for water distribution network. Mechanisms affecting system performance criteria are not all well understood. It is difficult to define and measure performance (which inherently comprises several non-commensurate and often conflicting criteria), let alone decide what level of performance is acceptable. It is also difficult to calculate the costs involved to achieve a specific level of performance. Substantial spatial and temporal variability is inherent in even a moderate-size network, and the collection of data on the performance and condition of these buried assets is often difficult and costly. At the National Research Council of Canada we have identified the need to address these issues in a holistic way, and in the last 15 years have been involved in a continual effort, both independently and in collaboration with others, to put the pieces of the puzzle together. Although the state of knowledge has advanced significantly since we started, a lot still needs to be achieved. This paper describes our past and current research activities, views and vision for future activities in the field.