Study of Environmental Effects of De-Icing Salt on Water Quality in the Twin Cities Metropolitan Area, Minnesota

A study was conducted to generate knowledge on the environmental effects of de-icing salt, particularly sodium chloride (NaCl), on water quality in Minnesota, especially the Twin Cities Metropolitan Area (TCMA). The Mississippi River receives substantial sodium chloride inputs from the Minnesota River and waste water treatment plants as it passes through the TCMA. In addition, road salt applications in the TCMA use about 350,000 short tons of NaCl every year. A chloride budget at the scale of the TCMA and on individual sub-watersheds in the TCMA indicates that about 70% of the road salt applied in the TCMA is not carried away by the Mississippi River. Rates of seasonal road salt use are correlated with snowfall, road miles and population. Salinity in TCMA lakes increases in winter and decreases in summer. Ionic composition of dissolved substances in lakes of the TCMA suggests unnaturally high sodium and chloride concentrations compared to lakes and other water bodies in the Midwestern U.S. Data indicate a rising trend in urban lake water salinity over the last 30 years. Shallow groundwater in the TCMA, especially near major roadways, has started to show increasing chloride concentrations. Salinity trends in lakes and shallow aquifers of the TCMA are of concern.

• Record URL:
  • https://hdl.handle.net/20.500.14153/mndot.2751
• Record URL:
  • http://www.lrrb.org/PDF/200842.pdf
• 
• Summary URL:
  • http://www.lrrb.org/media/reports/200842TS.pdf
• Corporate Authors:

  University of Minnesota, Twin Cities

  Department of Civil Engineering, 500 Pillsbury Drive, SE
  Minneapolis, MN  United States  55455

  Minnesota Department of Transportation

  Research Services and Library
  395 John Ireland Boulevard
  St Paul, MN  United States  55155
• Authors:
  • Stefan, Heinz G
  • Novotny, Eric
  • Sander, Andrew
  • Mohseni, Omid
• Publication Date: 2008-9

Language

• English

Media Info

• Media Type: Web
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 88p

Subject/Index Terms

• TRT Terms: Aquifers; Deicing chemicals; Environmental impacts; Groundwater; Lakes; Salinity; Sodium chloride; Water quality; Winter maintenance
• Geographic Terms: Twin Cities Metropolitan Area (Minnesota)
• Subject Areas: Environment; Highways; Maintenance and Preservation; I15: Environment; I62: Winter Maintenance;

Filing Info

• Accession Number: 01122491
• Record Type: Publication
• Report/Paper Numbers: MN/RC 2008-42
• Contract Numbers: 81655 (wo) 213
• Files: TRIS, STATEDOT
• Created Date: Feb 20 2009 4:19PM