| As Canadian municipalities venture into rehabilitation and replacement of extensively deteriorated underground water distribution and sewerage assets, municipal decision-makers, engineering and construction research bodies and the public all feel that this type of construction work can have adverse effects on the society. This thesis reviews these negative impacts which include, but are not limited to damage of nearby buried and above-ground infrastructure, disruption of traffic, loss of accessibility to businesses, health hazards to workers and the public, and finally environmental pollution and damage. There is presently no accepted practice-oriented method for the evaluation of these social, economic and environmental impacts. This research project proposes a framework to enable municipalities, utility agencies and contracting firms to quantitatively estimate the total cost to society of buried municipal infrastructure renewal projects using open trench, or trenchless construction methods. The total cost of a project is the sum of all the direct and indirect costs borne by the client organization, and external costs borne by society. The external costs can be separated into three components: social, economic and environmental costs. Use of the proposed methodology in a case study of a water main rehabilitation project using trenchless technologies in the city of Montreal, Canada, revealed that the indirect and external costs of the project were approximately 25 percent of its direct costs. The most significant cost components were those attributable to increased vehicular travel time and lost business income. |
