A Framework to Evaluate the Life Cycle Costs and Environmental Impacts of Water Pipelines

The true value of a pipeline as an asset should be based on several factors that impact its service life. Those considerations include the consumption and production of raw materials, design, installation, operation and maintenance, and planning for the end of the pipeline's service life; as well as, the corresponding environmental impacts at each of these life cycle phases. In this paper, a model is presented that allows utilities and engineers to evaluate the total life cycle cost associated with a water transmission pipeline. The model is designed to compare Ductile Iron (DI) versus PVC pipe, two of the most commonly used pipe materials. In addition to the tangible cost comparisons, the model also includes an evaluation of environmental impacts that need to be considered by utilities to build or replace a transmission pipeline. Results from scenario analysis for 8 '' and 24 '' pipes illustrate that although PVC pipes have initial economic benefits (due to lower material costs), DI tends to be more cost effective and also comparatively environmentally sustainable (less CO2 emissions) over its service life.