With warm weather comes the prospect of dusty country roads throughout the state, but local engineers are ready. Dusty gravel roads across Iowa will be tamed this summer with a couple new products, including one used to melt snow in winter. Dallas County engineer Jim George oversees 900 miles of county roads, and says 80-percent of those miles are dirt and gravel surfaced.He says they’ll use calcium chloride, a salt, and lignin which is a tree sap. Calcium chloride is used to melt snow in winter, but in summer it holds moisture in the roadway so traffic doesn’t stir up dust. Calcium chloride absorbs water like salt, so it keeps moisture under the roadway and holds down dust.He says the calcium won’t show, you’ll only notice less dust, but the lignin will look brown and oily on the road. They cost more than putting waste oil on the roads, but George says it’s worth it to keep the road’s surface from getting thrown up by traffic and drifting off as dust into nearby yards and fields. Iowa’s counties do not pay for treating gravel roads for dust; residents along the roadways are billed for the cost, and private contractors do the spraying.
