Salt Fact Sheet

A cost-effective highway de-icer
Road salt is used to deice highways in West Virginia because it is effective and relatively inexpensive. With all the traffic, grades and curves on our roads, the use of salt is the only practical method available to keep our highways safe in winter. During winter weather conditions, public safety is always the first concern of the West Virginia Department of Transportation and its Division of Highways.


Salt, the mineral
Common road salt is sodium chloride (NaCl), a naturally occurring mineral found in seawater. It's what makes the oceans salty. Salt is found in large underground deposits which are the remains of ancient seas. Road salt and table salt are essentially the same, though road salt often has a special anti-caking agent added.


Quantities & capacities
At full capacity, WVDOT stockpiles hold about 73,000 tons of salt. This amount may be adequate for a very mild winter. During the average winter, however, around 100,000 tons will be used. A severe winter, such as 1993-94, can require the use of 140,000 tons or more. For deicing use during extremely cold periods, the state also keeps approximately 40,000 bags of calcium chloride on hand. In addition, over 100,000 tons of anti-skid materials (sand, crushed stone and cinders) are stockpiled. They are either mixed with salt or spread singularly on the road. These materials are purchased locally and their type varies based on price and availability. At all DOT storage areas, salt is stored in buildings or covered piles.


How salt melts ice
Water normally freezes at 32 degrees Fahrenheit, but salt lowers its freezing point. So at temperatures between 32 and the low 20s, salt effectively melts ice and snow. Daily temperature cycles common to West Virginia in winter usually include highs above 20 degrees, thus allowing salt to melt ice into water so that it can drain off the road.


Highway deicing during very cold periods
During very cold periods – temperatures remaining below 20 degrees Fahrenheit – salt alone will not effectively melt the ice. On busy Interstates, bridges and intersections, alternative ice melting chemicals may be used. Deicers such as calcium chloride will melt ice at lower temperatures than salt but are much more expensive to use. In these times, traction-boosting materials like sand, cinders and crushed stone will still be effective and may be used alone.


Supply origin and shipping
Most salt used by the West Virginia Department of Transportation comes from mines in Louisiana and Texas. Salt vendors such as Morton International, Rochez and Cargill ship the rock salt up the Mississippi and Ohio rivers by barge to their storage depots in the region. Salt supplies for the Eastern Panhandle originate in New York and are shipped by rail to depots in Maryland. From the vendor depots, salt is delivered by truck to 140 DOT storage areas across the state. The average delivered price of road salt is $35 per ton.


The salt industry
Highway deicing accounts for the majority of sodium chloride use in the United States. Nationally, a total of 31.5 million tons of salt was used in 1994 in the following major end-user percentages (according to The Salt Institute):

• 59.8% Highway deicing
• 8.7% Industrial processes
• 8.2% Water conditioning
• 6.3% Agriculture
• 4.2% Human consumption