Projections of chloride concentrations in urban lakes receiving road de-icing salt

Eric Vladimir Novotny, Heinz Gunter Stefan

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

The chloride concentrations of urban lakes where road de-icing salt (NaCl) is used have increased to levels that can change natural lake-mixing behavior and influence aquatic life. A zero-dimensional model was formulated to project the long-term accumulation of chloride in urban lakes receiving runoff from roads on which road salt is applied. Four model parameters and an initial concentration were obtained by calibrating the model with 5 years (2004-2008) of monthly salinity data from seven lakes in the Minneapolis/St. Paul Twin Cities Metropolitan Area of Minnesota, USA. Three of the seven lakes appear headed towards year-round volume averaged chloride concentrations above the 230-mg/L chronic standard for impairment to aquatic habitat. The two lakes with the lowest projected equilibrium concentrations of chloride have already reached equilibrium. One lake is projected to take an additional 40 years to reach equilibrium under current climate conditions and current road salt application rates. If road salt application rates are reduced in future winters, it is projected that the lakes will respond with noticeably lower chloride concentrations within 5 to 10 years. If road salt applications are discontinued altogether, chloride concentrations are projected to drop to natural levels within 10 to 30 years in all seven lakes. A reduction of application rates by 50% would result in annual volumetric average chloride concentrations below the chronic standard.

Original languageEnglish (US)
Pages (from-to)261-271
Number of pages11
JournalWater, Air, and Soil Pollution
Volume211
Issue number1-4
DOIs
StatePublished - Sep 2010

Bibliographical note

Funding Information:
Acknowledgments Funding for the project, especially the data collection, was provided by the Local Road Research Board, St. Paul, MN, USA, and the James L. Record Fund, University of Minnesota. The University of Minnesota provided a Doctoral Dissertation Fellowship for the senior author.

Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.

Keywords

  • Lakes
  • Modeling
  • Road maintenance
  • Runoff
  • Salinity
  • Salt
  • Watershed
  • Winter

Continental Scientific Drilling Facility tags

  • SALT

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