Editing The Effects of Road Salt on the Environment and the Alternative
The Effects of Road Salt on the Environment and the Alternatives
The impacts that Road Salt has not only for our environment, but also on our wildlife is tremendous. The heavy use of road salts can lead to damage to vegetation. An example of this is road-side vegetation, which is damaged by salt-splash. Road salt rusts cars, can hurt trees and plants, and can even get into water supplies and harm freshwater, fish, and other organisms. It also leads to damage to organisms in soil, to birds, and other wildlife. 1) The effect on soil: Some of these effects include impact on soil structure, soil dispersion, soil permeability, soil swelling and crusting, soil electrical conductivity, and soil osmotic potential. These effects can in turn have a biotic impact on the environment. Biotic impacts include loss of soil stability during drying and wetting cycles, and during periods of high surface runoff and wind. Meanwhile, biotic impacts include osmotic stress on soil flora, as well as salt-induced mobilization nutrients that affect flora. 2) The effect on animals: Specific species such as mammals and birds have also been exposed to behavioral and toxicological impacts of road salts. The ingestion of road salt increases the vulnerability of birds to car strikes. Some calculations suggest that road salts may poison some of these birds. The reason for this being that, during severe winters, water is not freely available to birds, so they end up ingesting snow to relieve their thirst. 3) The affect on groundwater contamination: According to the Act 307 Sites of Environmental Contamination, road-salt is listed as a pollutant. In a 1992 groundwater awareness survey conducted by the Center for Science & Environmental Outreach, road salt was ranked as the most serious groundwater contaminant. It was ahead of other choices such as gasoline/oil, bacteria, pesticides, solvents and nitrates. What we can use for alternative: A. Calcium Magnesium Acetate, is an alternative to road salt. It is made from limestone and acetic acid and biodegrades easily. It is less damaging to soils, less corrosive to concrete and steel, and non-toxic to aquatic organisms. It may also reduce oxygen level in streams or ponds receiving runoff from roads. (Wyatt and Fritzche, 1989) According to a 1990 survey conducted by the book,” Better Roads”, 45 percent of highway engineers reported using calcium chloride, and one-fifth used CMA. The biggest disadvantage of CMA is that it is expensive. Costs of the major alternative de-icers such as calcium chloride, CMA, and corrosion-inhibited salt range from $110 to $1,200 a ton, compared to $25 a ton for road salt. B. Calcium Chloride, It is the second most commonly used de-icing chemical. It is effective in as low temperatures as 0 F. Calcium chlorides can be used to pre-wet salt and sand. There are also disadvantages to calcium chloride. The first one is already stated above, that it is more expensive than salt. The second disadvantage is that it is difficult to handle and store. The third disadvantage is it is corrosive to structural materials and toxic to aquatic life as salt. C. Sand, can provides additional traction in slippery conditions. A disadvantage of salt is it cannot melt snow or ice on the road. Another disadvantage is that, at the end of winter, sand has to be cleaned up in order to prevent clogging and sedimentation in water bodies. Road salt can have many positive and negative effects on the environment, mostly negative, basically to try to find alternatives to using road salt to primarily benefit our environment.
Sources: • Better Roads Magazine, 1989 Salt Alternatives tests. March 1989:43-45 • CEPA 1999, Canadian Environmental Protection Agency, section 64 • Institute for Safety Analysis, 1986 De-icing salt facts. Alexandria, Va, p. 4