Rethinking Wastewater-Treatment Infrastructure: Case Study Using Life-Cycle Cost and Life-Cycle Assessment to Highlight Sustainability Considerations

Abstract

Making U.S. infrastructure more sustainable by reducing long-term infrastructure costs is a stated goal of the U.S. EPA. A case study of a small development in northern Colorado used both life-cycle cost (LCC) and environmental life-cycle assessment (LCA) to better exemplify how this goal might be attained and also provide environmental benefits. By choosing community-scale technology (CST) for wastewater treatment application, the developer obviated the need to construct 10.46 km of main sewer line needed to connect to an existing centralized wastewater treatment facility. By eliminating the need for the 10.46 km main sewer line, the LCC, global warming potential from greenhouse gasses, energy use, and hazardous waste creation and disposal were reduced significantly. In the future, the use of CST in redevelopment planning for shrinking cities may have additional benefits to area residents and landowners. This work is significant to decision makers in the wastewater treatment community for two reasons. First, it provides alternatives for sewer districts to consider in the design phase of new and redevelopment projects that could impact scope, first costs, and LCC, all of which flow through to the user in a fee structure. Second, it is the first study using LCC and LCA to focus on sustainability considerations of wastewater infrastructure in shrinking cities and redevelopment applications.