After a snow or ice fall, the city streets are treated with ordinary rock salt. In some areas, the salt is combined with calcium chloride, which is more effective in below-zero temperatures and better melts ice. This combination of salt and calcium chloride is also less damaging to foliage along the roadways. In deciding whether to e ordinary rock salt or the salt andcalcium chloride on a particular street, which of the following isNOT a consideration?