Implications of the Implementation of Magic Salt as an Alternative to Sodium Chloride for

Treatment of Winter Road Conditions

OverviewWhat’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

–Used since the 1940sUsed since the 1940s•Salt + plowing are most efficient in Salt + plowing are most efficient in keeping roads clearkeeping roads clear•Least expensive of currently available Least expensive of currently available optionsoptions•Application frequency and amount are Application frequency and amount are weather-relatedweather-related•~16 million tons used in the US during ~16 million tons used in the US during 20042004

–Evidence that application at current rates is Evidence that application at current rates is changing historical water concentrationschanging historical water concentrations

Source: Angela ShambaughVermont Department of Environmental Conservation

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

Vermont: Current PracticesState: Average 110,000 tons per year.

Burlington: 500 lbs/ mile per storm.

Source: Vtrans Winter Management Plan.

Human Health ConcernsDrinking water contamination

Taste issuesHypertension (Jackson and Jobbagy. 2005)

Heavy metals

Health ImpactsEPA standards 20mg/L for NaCl

Most concentrations found are much lowerRoad salts are not a direct risk to human

health (Hausebeck et al. 2004)

Infrastructure ProblemsCorrosivity 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 ImplicationsRoad salts have multiple effects

Melt iceProvide traction in wet/icy road conditions

Icy roads and sidewalks create a hazard for humans on foot and in their vehiclesRoad salts are necessary for managing risks to

human societies

Environmental ImpactsSoil

Vegetation

Ground & Surface Water

SoilsSodium (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)

VegetationChloride 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 riskSpecific 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)

SandPhosphorus aquatic habitat in streams,

wetlands, and rivers create air quality or dust

concernsclogs drainage features

along highwaysincrease 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).

AdvantagesReduce 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°FEconomically viable

DisadvantagesPhosphorus - 50.8 ppm or less Upfront costs

Calcium Magnesium Acetate (CMA)Calcium and Magnesium ChloridesPotassium and Sodium AcetatesUrea 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

ProsWorks at lower tempsLess corrosive than sodium chloride

ConsCalcium Chloride causes skin and soft tissue

necrosisMagnesium Chloride contains cadmium- a

known carcinogen

Potassium and Sodium Acetates Work at low temperatures- 0ºFWork very fastNo nitrogen or chloride

UreaUsed where chlorides cannot be toleratedToxic effects

Glycol

Each have their placeCan chloride be tolerated?Scale$$$

None better than Magic Salt

Chlorides reach unacceptable levels during storm events

Magic salt is the way to goLess chloride entering waterwaysMore effectiveMoney saved by municipal and commercial

applicators