Water, (Salty) Water Everywhere

Last week, I heard an interview on my local NPR station with a woman discussing the detrimental effects of salting roads during winter weather conditions — the principal issue being that the salt washed away with melting snow and ice pollutes ground water and bodies of water, ultimately reaching plants and wildlife.

Essentially, when the sodium-chloride road salt combines with water, the electrically-charged chlorine atoms break away and accumulate in astonishingly high levels in water sources (a 1997 Danish study found that chloride levels in winter were 1,200 times higher than in summer). Water treatment plants are not constructed to cleanse this level of chloride contamination, so the water makes its way through the ground and also through sewer systems to sources of both human and non-human consumption. The problem with chloride-filled water is that it essentially cannot quench thirst — especially in plants and small animals. Here’s the quick and dirty biology: The chlorides collect on the outside of a plant’s or animal’s cell membranes, unable to cross into the cell, creating a mineral imbalance; the water inside the cell then leaches out via osmosis to correct this imbalance, thus dehydrating the plant or animal. (This is why humans can’t rehydrate on a hot day at the beach by drinking sea water.)

The NPR-show interviewer posed an interesting question: “So, isn’t this another example of a strategy invented by humans to deal with a natural phenomenon that actually causes a larger problem in the end?” Right on. The upside of road-salting is that far fewer people are dying in auto accidents on icy roads. There are, however, other options to explore — though most are either far more expensive (for example, there are high-tech monitoring systems that detect optimal time and conditions to salt, decreasing salt usage by two-thirds in some cases) or far more inconvenient (for example, don’t drive on icy roads!).

We haven’t used any de-icing salt on our sidewalks or driveways yet this winter, and I’m glad for it. Sure, we’ve had to be more timely, aggressive and creative with our snow-removal techniques (I found that the flat-tipped garden shovel works wonders on the slabs of ice that form under car wheels, even though that shovel is heavy-so-heavy), but that’s an extra bit of workload I’m willing to take on in this situation. Of course, we’re just one house surrounded by neighbors who are a bit salt-happy, and located on a major road that is salt-ecstatic, but — heck — it’s a start.