Case study and life cycle assessment of a coastal utility facing saltwater intrusion

A case study was conducted on a saltwater intrusion event that affected a coastal water utility in Florida. The conductivity of the groundwater increased from approximately 500 to 4,000 ÎS/cm. The possible causes of the saltwater intrusion event were explored, and the steps taken by the water utility to manage the saltwater intrusion were documented. To understand the environmental impact of the saltwater intrusion event on drinking water treatment, the life cycle assessment (LCA) method was used, comparing the original water treatment plant with virtual treatment trains that could treat source waters ranging from freshwater to seawater. Specifically, the LCA results showed the change in environmental impacts between chemical-intensive and electricityintensive processes. As such, an LCA toolbox is proposed; with national and international participation, an LCA toolbox could be used by water utilities as part of the decision-making process when confronting major changes in water quality and treatment.