With the recent snow and frigid temperatures, many of us have worked hard to clear our porches, driveways and sidewalks of snow and ice. Commonly we simply spread salt over these areas - it is simple and it works. Salt, though, can damage some metals, concrete, and asphalt, and can be harmful to plants, lakes and ponds, and drinking water. Less threatening alternatives to salt are readily available.
Two low-corrosion alternatives to salt that are being sold in many stores this season are calcium magnesium acetate (CMA) and calcium chloride. Salt breaks down the surfaces of metals, concrete and asphalt, causing cracking and weakness with extended use season after season, where CMA and calcium chloride are only as corrosive as ordinary tap water.
Neither CMA nor calcium chloride are harmful to vegetation where salt can be deadly to shrubs, orchards, gardens, and trees. CMA actually strengthens the soil and can stimulate plant growth by providing abundant organic acid in the way that liming a garden improves vitality.
In surface water such as streams, lakes, and ponds, CMA does not stimulate algae growth or kill aquatic plants as salt does. For CMA or calcium chloride to be as damaging to aquatic life as salt is, there would have to be three times the accumulation as that of salt to achieve even half of the damage.
Of course, there is the old chemical free option of shoveling. If you want to minimize the amount of work, just shovel a small walking path on sidewalks and two tire paths on driveways. Shoveling these pathways clear even part of the time while using CMA or calcium chloride the other part reduces the chance of accidents and also lowers the threat of salt and chemical damage to the environment.