Consideration of Embodied Energy in Sustainability Evaluation of Pipeline Projects

In the water and wastewater industry, the sustainable properties of pipe materials are often presented in a form not suitable for a quantifiable comparison of alternate pipe materials. To quantify how and where a pipe material would impact the environment is very complex. The complexity is not only in the collection and evaluation of pertinent data, but is also characterized by the variety of materials involved and the differences in design, manufacturing, and installation processes of various pipes for the intended purpose. Embodied Energy (EE) analysis affords a methodology for quantifying the differences between various pipe alternatives for specific specifications. The EE is a parameter that can be used in a more comprehensive Life Cycle Analysis (LCA). While EE can be broadly defined to include raw resources, manufacturing, installation, operation and end-of-life recycling and/or disposal; as a first step the ASCE Task Committee for the Sustainable Design of Pipelines (SDP) has elected to limit the scope of the EE parameter to cradle-to-gate with selective consideration of end-of-life parameters. The boundary of the cradle-to-gate EE parameter terminates at the point where the pipe product leaves its manufacturing facility. With this limited boundary, EE is defined by the amount of energy consumed in acquiring all necessary raw materials, the production of intermediate products, and the manufacturing of the finished pipe product that has been designed for its intended use. It should be noted that EE alone has no consideration of emissions or the impact of by-products to the environment and as a result does not replace or substitute for a Life Cycle Cost (LCC) analysis. However it should be noted that as the EE parameter is developed, it can be associated with environmental impact markers to allow a more comprehensive input parameter to a project's LCA and/or a Carbon Footprint Analysis.