Road salts and freshwater salinization syndrome: an emerging water quality threat

Streams throughout the U.S. and world-wide have increased in salinity due to multiple processes, including road salt and human-accelerated weathering of impervious surfaces, reductions in acid rain, and other anthropogenic legacies. This freshwater salinization, in turn, mobilizes chemical cocktails via ion exchange and other biogeochemical processes. This webinar will examine fate and transport of salts and chemical cocktails, describe environmental impacts, and discuss the use of real-time sensor data to characterize trends of nutrients and metals using long-term data from urban streams in the Chesapeake Bay watershed. In addition, approaches to managing this growing environmental and health problem will be discussed.

Impact/Purpose

Salinization of freshwater has increased in the US and elsewhere around the world due to road salts and other anthropogenic and geologic sources creating a phenomenon termed freshwater salinization syndrome that includes increased concentrations of contaminants such as heavy metals and nutrients in have increased due to ion exchange processes resulting in water quality impacts.  We present data from multiple studies over our long-term research efforts to demonstrate the factors including human activities, flowpaths, geology, climate, and time in driving the progression of freshwater salinization and subsequent impacts to water quality.  We discuss monitoring approaches for understanding the behavior of salts and chemical cocktails during flashy flows in stream and stormwater systems.  Finally, we discuss potential for employing restoration and stormwater management approaches to attenuate salt concentration and pulses in urban aquatic ecosystems. 

Citation

Mayer, P., T. Newcomer-Johnson, J. Galella, AND S. Kaushal. Road salts and freshwater salinization syndrome: an emerging water quality threat. EPA/ORD Water Research Webinar Series (https://www.epa.gov/water-research/water-research-webinar-series), virtual, Virtual, June 30, 2021.