Is all water conservation created equal? Effects of source water quality on life cycle impacts of drinking water production

摘要

Life cycle assessments of drinking water treatment are a necessity for minimizing the environmental burdens of drinking water production. Previously conducted life cycle assessments of drinking water treatment facilities show the potential to identify hot spots of environmental impact within a system, thus highlighting areas with the most opportunity for improvement, as well as the ability to compare alternative technologies and provide a systemslevel evaluation of regulatory actions. This work focuses on the promise of life cycle assessments to provide a more comprehensive understanding of the short- and long-term impacts of water conservation. Life cycle assessment models were constructed for six U.S. drinking water treatment plants using operational data spanning several years. These impacts were related to water demand and other factors to determine the treatment inputs and outside factors that most affect the environmental footprint of water treatment. The results for two water treatment plants are discussed here to demonstrate methodology and the insights gained from this type of analysis. Results show that water conservation efforts and associated reductions in potable water consumption not only benefit the water resource itself, but also the upstream impacts required for its production. These upstream impacts are entirely dependent on the water treatment plant in question and are also a function of temporal variations in source water quality. Overall, this work suggests that water demand management is a tool for addressing water quantity, as well as changes in water quality.