William M. Lewis, Jr.

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Studies on the Environmental Effects of Deicing
Chemicals

• William M. Lewis, Jr.
• Professor and Director, Center for Limnology
• Cooperative Institute for Research in
  Environmental Sciences
• University of Colorado, Boulder, CO 80309-0216
• Email lewis_at_spot.colorado.edu

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Introduction Types of Ice and Snow Control
Agents Categories of Environmental Issues
Focus on the Aquatic Environment The Role of
Climate
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• Framework for
• Environmental Protection (U.S.)
• Clean Water Act
• Clean Air Act
• Endangered Species Act
• State and Local Legislation

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A Closer Look at the Clean Water Act
Classification System Water Quality
Standards National Pollutant Discharge
Elimination System (NPDES) Urban
Runoff Permitting
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• Relevance of Water Quality Standards
• Beneficial Uses of Water
• Thresholds of Toxicity

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Composition of Snow and Ice Control Compounds
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Summary of Constituents
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Strategy for Environmental Evaluation
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Major Constituents Particulate Abrasives
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Soluble Material Carried by Abrasives
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Chloride
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Alkaline or Alkaline Earth Cations Ca, Mg, Na, K
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Total Salt Content ? Density Flows ?
Meromixis (salt layering)
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Organic Matter ? BOD Concept ? Effect on
Oxygen Concentration
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Additives ? Heavy Metals ? Other Inorganic
Substances ? Organic Matter
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Contaminants ? Phosphorus ?
Nitrogen
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Other Inorganic Substances
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Evaluation of Specific Vendor Products
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Dilution Near the Roadway
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Overview of Factors Influencing Concentration
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Evaluation by Bioassay
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Overview of Commonly Used Materials
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Conclusions