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