$EPA NRMRL \ NATIONAL RISK MANAGEMENT RESEARCH LABORATORY www.epa.gov/nrmrl GROUND WATER AND ECOSYSTEMS RESTORATION RESEARCH The Influence of Road Salts on Water Quality in a Restored Urban Stream Road salts (also known as de-icers) are essential to the transportation and highway maintenance industry in the United States. They keep roadways passable for both commercial and personal vehicles. Often these de-icing salts wash from roadways into nearby bodies of water and become a nonpoint source pollutant that can affect water quality and aquatic organisms. Studies have shown that road salts can accumulate in streams and ground water, persisting beyond the time of application, often into the summer months. These results coincide with initial findings at Minebank Run, a recently restored urban stream in Baltimore County, Maryland, that has been the subject of a long-term water quality study. Surface and ground water data have been collected in Minebank Run since November 2001, including water levels and a suite of chemical parameters. One of the project objectives was to understand the salt chemistry of surface and ground water and the implications for ecological or human health. Biweekly sampling, well installation, and other project operations were done in conjunction with the U.S. Geological Survey. Chemistry and water levels were measured from a network of surface water locations and ground water wells (piezometers) installed along transects perpendicular to the stream flow within two primary study locations, one upstream and the other downstream of the 1-695 beltway. EPA scientists are examining ground water/surface water interaction and subsurface flow paths as factors influencing salt retention and ground water quality. The scientists have found that salt levels (chloride and sodium) at Minebank Run are chronically elevated throughout the year, even in summer when 110 salts are applied. Chloride and sodium levels are significantly higher downs tream of the 1-695 beltway, suggesting that this major roadway is a significant source of road salts to ground and surface water in this watershed. Research is ongoing to better determine the source zones and residence times of road salts in the Minebank Run watershed. More information Cooper, C.A. and P.M. Mayer. (2009). "Surface and Ground Water Quality in a Restored Urban Stream Affected by Road Salts:' Presentation, Geological Society of America (GSA) Annual Meeting, From Volcanoes to Vineyards: Living with Dynamic Landscapes. Cooper, C.A., P.M. Mayer, and B.R. Faulkner. (2008). "The Influence of Road Salts on Water Quality in a Restored Urban Stream."' In 16th National Nonpoint Source Monitoring Workshop. Edited by J. D'Ambrosio. The National Risk Management Research Laboratory's mission is to advance scientific and engineering solutions that enable EPA and others to effectively manage current and future environmental risks. NRMRL possesses unique strengths and capabilities and is dedicated to providing credible technological information and scientific solutions that support national priorities and protect human health and the environment. ------- Doheny, E.J., R.J. Starsoneck, P.M. Mayer, and E.A. Striz. (2007). "Pre-Restoration Geomorphic Characteristics of Minebank Run, Baltimore County, Maryland, 2002-04." U.S. Geological Survey Scientific Investigations Report 2007-5127, 49 p. Doheny, E.J., R.J. Starsoneck, E.A. Striz, and P.M. Mayer. (2006). "Watershed Characteristics and Pre-Restoration Surface Water Hydrology of Minebank Run, Baltimore County, Maryland, Water Years 2002-04." U.S. Geological Survey Scientific Investigations Report 2006-5179, 42 p. Investigators Curtis A. Cooper Barton R. Faulkner Paul M. Mayer U.S. EPA Ground Water and Ecosystem Restoration Division Ada, Oklahoma 74820 The National Risk Management Research Laboratory's mission is to advance scientific and engineering solutions that enable EPA and others to effectively manage current and future environmental risks. NRMRL possesses unique strengths and capabilities and is dedicated to providing credible technological information and scientific solutions that support national priorities and protect human health and the environment. ------- |