The Global Threat Of Salt Contamination To Water Supplies

Research from Weitzman’s Allison Lassiter and an international team of researchers highlights how a combination of climate change impacts and localized human activities are intensifying the increase in salt in vital freshwater sources.

A new paper published in Environmental Science & Technology Letters warns of an emerging global threat posed by salt contamination of water supplies in tidal rivers worldwide. This global perspective paper, co-authored by Weitzman School of Design associate professor Allison Lassiter and an international team of researchers, highlights how a combination of climate change impacts—including prolonged drought and rapid sea-level rise—along with localized human activities, are intensifying the increase in salt in vital freshwater sources.

Beyond agricultural irrigation, salt contamination poses a substantial threat to industrial production and critical infrastructure through corrosion, compromising power plant cooling systems, water treatment plants, bridges, and other vital components.

Surface waters such as tidal rivers, which provide approximately two-thirds of the global drinking water supply, are increasingly vulnerable to saltwater intrusion. Key findings from the study show how accelerated relative sea-level rise, altered drought and river flow, and extreme weather events are significantly increasing saltwater intrusion. Additionally, local human activities, such as channel deepening in estuaries, excessive use of salt on roadways, and other human-accelerated chemical weathering in watersheds, have historically contributed to and continue to exacerbate salinity issues.