Date of this Version
Moussavi, S. (2019). "Environmental Sustainability Assessment of Small Nebraska Mechanical Water Resource Recovery Facilities: Impacts of Construction and Operations." MS Thesis, University of Nebraska-Lincoln.
Many small, rural communities struggle with aging or inadequate water resource recovery facilities (WRRFs), and face challenges in constructing and operating such systems. Although existing literature has provided insight into the environmental sustainability of large systems including both the construction and operational phases, these studies have not examined small systems in adequate depth or breadth. The environmental impacts associated with construction may be notable for small WRRFs since the initial construction can be a larger share of the total life cycle environmental impact.
The goal of this work is to provide the environmental sustainability profiles of 12 mechanical WRRFs in Nebraska using life cycle assessment (LCA) methodology. A detailed inventory of the construction and operational data was developed. Foreground data was collected from site visits, regulators, consulting engineers, and online databases. Background data was collected via the Ecoinvent database. The environmental profiles were created using SimaPro and the TRACI impact assessment method.
Both the construction and the operational phases should be considered when evaluating the environmental sustainability of a small WRRF. For a majority of the impact categories, the individual contribution of the construction phase and operational phase to the overall environmental burden is higher than 5%. Variability among the 12 profiles was observed. Key factors influencing this variability include operational energy, construction materials, and overdesign of a facility. It was found that high operating energy impacts are associated with operational issues at a facility, and high construction impacts are associated with auxiliary materials. WRRFs that are overdesigned typically possess high environmental impacts due to high operational energy usage and/or overdesigned infrastructure.
Three scenario sensitivity analyses were performed to evaluate factors that influence the environmental sustainability profile of a plant. These analyses evaluated design life, alternative energy sources, and end-of-life impacts. The results of this study have been compiled into a summary table, which may be especially useful for key stakeholders during the initial planning and design phase of small WRRFs.
Advisor: Bruce I. Dvorak