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Life Cycle Assessment and Cost Analysis of Potable Reuse
Citation:
Morellis, B., S. Arden, J. Garland, Cissy Ma, AND M. Jahne. Life Cycle Assessment and Cost Analysis of Potable Reuse. 38th Annual WateReuse Symposium, Atlanta, GA, March 05 - 08, 2023.
Impact/Purpose:
A life cycle assessment (LCA) and life cycle cost analysis (LCCA) study will be conducted to estimate environmental impact and cost of operating an existing indirect potable reuse (IPR) system in Gwinnett County, Georgia and compares that impact to two hypothetical direct potable reuse (DPR) scenarios centered on reverse osmosis (RO) and ozone-biologically activated carbon (ozone-BAC). The study will shed more light on water reuse practices.
Description:
Summary: A life cycle assessment (LCA) and life cycle cost analysis (LCCA) study that estimates environmental impact and cost of operating an existing indirect potable reuse (IPR) system in Gwinnett County, Georgia and compares that impact to two hypothetical direct potable reuse (DPR) scenarios centered on reverse osmosis (RO) and ozone-biologically activated carbon (ozone-BAC). Learning Objectives: Attendees will learn about the comparative economic cost and environmental impact/benefit of IPR and DPR water reuse systems. Attendees will learn about potential barriers to DPR implementation. Full Description: This presentation will present the results of a case-study life cycle assessment (LCA) and life cycle cost analysis (LCCA) study that estimates environmental impact and cost of an existing indirect potable reuse (IPR) system in Gwinnett County, Georgia compared to two hypothetical direct potable reuse (DPR) scenarios. One DPR treatment configuration is the fully advanced treatment (FAT) system, widely used in California for IPR, which relies on Reverse Osmosis (RO) and an Ultraviolet Advanced Oxidation Process (UV AOP). The second DPR treatment configuration consists of a modified ozone-biologically activated carbon (ozone-BAC) treatment process with enhanced biological nitrogen removal and high-dose UV. Two blend ratio scenarios are examined for each DPR treatment system representing 50% and 80% reuse rates. This research was carried out as a partnership between Gwinnett County and the U.S. Environmental Protection Agency with the goal of advancing the understanding of the environmental impacts and benefits of direct and indirect potable reuse and the potential comparative environmental and cost advantages of ozone-BAC systems that have greater feasibility in inland regions, where RO brine management can be difficult or costly. This project builds on a report released in 2018 by the Water Research Foundation that documents the results of a pilot project evaluating the feasibility of non-RO DPR at Gwinnett Counties’ wastewater and drinking water treatment facilities. This analysis expands on the scope of that project to include an assessment of life cycle environmental impacts while addressing water quality exceedances observed at higher blend ratios. The treatment configurations have been updated to address water quality issues related to nitrate, bromate, N-nitrosodimethylamine (NDMA), cyanide, and total dissolved solids (TDS). LCA is an established methodology used to quantify a broad range of environmental impacts across a product’s life cycle. In the context of water reuse the scope of the analysis aggregates environmental impacts associated with energy and material requirements for water treatment, influent and effluent quality, and RO brine, sludge and other waste disposal. This study presents results for climate change, eutrophication potential, water depletion and scarcity, energy demand, and several air quality indicators. The LCCA provides a similarly comprehensive perspective on economic cost over a 30-year time horizon. By examining a diversity of environmental and cost indicators this research informs a holistic understanding of IPR and DPR treatment systems, their potential impacts and benefits, and an assessment of comparative performance that aims to prevent the shifting of burdens across indicators. The results of this research are intended to promote a more informed decision-making process.