Ecological Risk Assessment

Ecological Risk Assessment Implications of the Implementation of Magic Salt as an Alternative to Sodium Chloride for Treatment of Winter Road Conditions

Overview • What’s the problem? • Background • Impact of NaCl on humans and the environment • All About Magic Salt • Other alternatives • Conclusions

Problem Statement • Sodium Chloride has multiple detrimental effects on numerous aspects of the environment and human health. • These entities are currently exposed to large amounts of NaCl due to road and sidewalk salting in the winter months in the state of Vermont

National Trends Used since the 1940s Salt + plowing are most efficient in keeping roads clear Least expensive of currently available options Application frequency and amount are weather-related ~16 million tons used in the US during 2004 Evidence that application at current rates is changing historical water concentrations Source: Angela Shambaugh Vermont Department of Environmental Conservation

“Increased Salinization of Fresh Water in the Northeastern United States.” Sunjay S. Kashual

Vermont: Current Practices State: Average 110,000 tons per year. Burlington: 500 lbs/ mile per storm. Source: Vtrans Winter Management Plan.

Human Health Concerns • Drinking water contamination • Taste issues • Hypertension (Jackson and Jobbagy. 2005) • Heavy metals

Health Impacts • EPA standards 20mg/L for NaCl • Most concentrations found are much lower • Road salts are not a direct risk to human health (Hausebeck et al. 2004)

Infrastructure Problems • Corrosivity of NaCl • Dissociation of NaCl in water increases conductivity of water (Wegner and Yaggi. 2007) • Water then oxidizes metals in bridges, parking garages, and vehicles • Structures are weakened

Public Safety Implications • Road salts have multiple effects • Melt ice • Provide traction in wet/icy road conditions • Icy roads and sidewalks create a hazard for humans on foot and in their vehicles • Road salts are necessary for managing risks to human societies

Environmental Impacts • Soil • Vegetation • Ground & Surface Water

Soils • Sodium (Na+) ions less mobile through soil. • Displace Nutrients at cation exchange sites. • Reduce nutrient availability for plants (Zn, Mg, N) • Mobilize organic matter. • Increase mobility of heavy metal ions (Cu, Zn, Cd etc.) and H+ ions. • Increased salinity and acidity of surface water. (Lofgren 2000)

Vegetation • Chloride is readily taken up by plants. • Essential for various plant processes but is toxic at high concentrations. • Vegetation located within 200m of roadways is most at risk • Specific effects from chloride • inhibition of water and nutrient absorption, osmotic stress, reduced flowering and seed germination, reduced shoot and root growth, browning of leaves and premature leaf drop, thinning of tree crowns, increased vulnerability to stresses and disease and even death

Water quality • Physical alteration of water bodies • Streams and Rivers can accumulate concentrations (sediment pore water) toxic to sensitive organisms. • Accumulates in larger bodies of water. • Creates dense water layer at the bottom. • Alters natural, seasonal stratification cycles. • Alters structure of microbial communities • Effects nutrient cycles (inhibits denitrification). (Hale 2006)

Sand • Phosphorus • aquatic habitat in streams, wetlands, and rivers • create air quality or dust concerns • clogs drainage features along highways • increase stream turbidity

Magic Salt & Magic 0

What is it? • Magic 0 - liquid deicer • Agricultural byproducts generally include: • (1) sugar-based byproducts of the distilling process, • (2) byproducts of corn steeping, • (3) manufactured corn-based products, • (4) other carbohydrates (Tierney & Silver, 2002).

Advantages • Reduce amount of chloride and sand • Reduce rock salt applications by 30 - 50 % • Keene, N.H. • University of Vermont • Binghamton, N.Y. • Working temperature of -35°F • Economically viable

Disadvantages • Phosphorus - 50.8 ppm or less • Upfront costs

Calcium Magnesium Acetate (CMA) Calcium and Magnesium Chlorides Potassium and Sodium Acetates Urea and Glycols

Not Corrosive Biodegradable Low levels of concrete spalling Negligible effects on ground and surface water Requires fewer applications Safe and beneficial to vegetation and soils No chlorides or nitrogen

Working temperatures above 15ºF 20 minutes to start working Expensive - $2800/ metric ton

Pros • Works at lower temps • Less corrosive than sodium chloride • Cons • Calcium Chloride causes skin and soft tissue necrosis • Magnesium Chloride contains cadmium- a known carcinogen

Potassium and Sodium Acetates • Work at low temperatures- 0ºF • Work very fast • No nitrogen or chloride • Urea • Used where chlorides cannot be tolerated • Toxic effects • Glycol

Each have their place • Can chloride be tolerated? • Scale • $$$ • None better than Magic Salt

Chlorides reach unacceptable levels during storm events • Magic salt is the way to go • Less chloride entering waterways • More effective • Money saved by municipal and commercial applicators

Ecological Risk Assessment