Impacts of Road Salt Runoff on Water Quality of the Chicago, Illinois, Region

Research Article| February 01, 2012 Impacts of Road Salt Runoff on Water Quality of the Chicago, Illinois, Region WALTON R KELLY; WALTON R KELLY 1 University of Illinois, Illinois State Water Survey, 2204 Griffith Drive, Champaign, IL 61820-7495 1Corresponding author email: wkelly@illnois.edu. Search for other works by this author on: GSW Google Scholar SAMUEL V PANNO; SAMUEL V PANNO University of Illinois, Illinois State Geological Survey, 615 East Peabody Drive, Champaign, IL 61820-6964 Search for other works by this author on: GSW Google Scholar KEITH C HACKLEY KEITH C HACKLEY University of Illinois, Illinois State Geological Survey, 615 East Peabody Drive, Champaign, IL 61820-6964 Search for other works by this author on: GSW Google Scholar Author and Article Information WALTON R KELLY 1 University of Illinois, Illinois State Water Survey, 2204 Griffith Drive, Champaign, IL 61820-7495 SAMUEL V PANNO University of Illinois, Illinois State Geological Survey, 615 East Peabody Drive, Champaign, IL 61820-6964 KEITH C HACKLEY University of Illinois, Illinois State Geological Survey, 615 East Peabody Drive, Champaign, IL 61820-6964 1Corresponding author email: wkelly@illnois.edu. Publisher: Association of Environmental & Engineering Geologists First Online: 02 Mar 2017 Online ISSN: 1558-9161 Print ISSN: 1078-7275 © 2012 Association of Environmental & Engineering Geologists Environmental & Engineering Geoscience (2012) 18 (1): 65–81. https://doi.org/10.2113/gseegeosci.18.1.65 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation WALTON R KELLY, SAMUEL V PANNO, KEITH C HACKLEY; Impacts of Road Salt Runoff on Water Quality of the Chicago, Illinois, Region. Environmental & Engineering Geoscience 2012;; 18 (1): 65–81. doi: https://doi.org/10.2113/gseegeosci.18.1.65 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract Road salt runoff has heavily impacted the water quality of surface water and groundwater in the Chicago, IL, region. High salt contents in surface water and groundwater pose a significant threat to aquatic ecosystems and to infrastructure and industrial operations. Almost all of the rivers and streams monitored have had significant increases in chloride (Cl−) and sodium (Na) concentrations since the mid-1970s. Rates of Cl− increase for several of the streams are in excess of 10 mg/L/yr. Concentrations of Cl− and Na are significantly higher during the winter months as a result of direct runoff from freshly salted roadways. In recent years, Cl− and Na concentrations have increased most rapidly in the Fox River Basin west of the Chicago metropolitan area, where land use is rapidly changing from rural to urban. Chloride and Na concentrations are also increasing in shallow aquifers in the Chicago region. Surface waters currently have approximately equimolar concentrations of Cl− and Na, while groundwater impacted by road salt tends to have an excess of Cl− relative to Na, suggesting Na retardation in the subsurface, likely due to cation exchange. A rough estimate of inputs and outputs of Cl− in the Chicago region suggests that most of the road salt applied in a year is removed by surface discharge. However, about 14 percent of the road salt is retained in the subsurface, approximately 50,000 metric tons of NaCl annually, representing a long-term source of Cl− and Na and other associated ions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.