A Salty Tale
by Scott Moeller
For me, consumer products provide no end of entertaining questions: Why does my new shaving razor have more blades than my kitchen blender? Why does that toothbrush have more horsepower than my Toyota Corolla? Is it really necessary to warn milk drinkers that the product in the jug “may contain milk”? What’s with the “no diving” warnings on the sides of 8” deep kiddie pools? I love these odd consumer product quirks and I usually notice them right away.
But one new consumer gimmick almost had me fooled recently at my favorite fast food restaurant. There it was in giant letters next to an oversized image of french fries: “Now with Sea Salt!” I must be a typical consumer, because my immediate response was to raise my eyebrows in curiosity and think “Oooh, sea salt!” As I shoved young children and infirm elderly customers out of my way to get to the ordering counter, I mentally berated myself for having ever been satisfied with crummy old table salt.
As I sat down with my tray, I was brimming with confidence that having sea salt on my french fries would surely be a life-altering experience. But moments later, as I realized that these new fries tasted pretty much the same as the old ones, it dawned on me: Table salt and sea salt are essentially the same thing. Sodium chloride is sodium chloride. (I’m not sure exactly how I thought it would be different. Maybe I thought I would see little bits of crab shell clinging to the fries, or perhaps I expected to find a sand dollar at the bottom of the container -- truth be told, I kind of expected it would make me feel a little like a pirate for some reason.)
Of course. 98% of sea salt is sodium chloride. That’s because the salt in the oceans today originally came from salt on the land. When rain falls and runs across the land, it picks up many dissolved salts (including sodium chloride) and then ultimately empties into a river and then an ocean. When the water evaporates from the ocean, only pure water evaporates, leaving the salt behind. This process, over hundreds of millions of years, has made our oceans increasingly saltier and saltier.
This natural process, called salinization, has resulted in today’s oceans being approximately 3% salt. That’s pretty salty. If you could remove all that salt and spread it evenly over all of the Earth’s land surfaces, it would form a layer of salt as deep as a 40-story building.
Because they evolved under these conditions, ocean organisms are adept at living in such salty water. However, freshwater aquatic plants and animals that we are more familiar with like pondweed, bluegills and leopard frogs cannot tolerate high levels of sodium chloride in their water. It’s really the chloride part that’s the biggest problem since the chloride ion “sticks” to water molecules very well, and causes lots of problems.
Unfortunately, we are learning that it’s not just the ocean that is getting saltier. Freshwater lakes and streams right here in Minnesota are obtaining higher and higher chloride concentrations. Results from the Nine Mile Creek study that Roland Sigurdson mentioned in his Community Connections article demonstrated routine levels of 0.5% to 1.0% chloride in the southwest metro creek, with seasonal spikes occasionally higher than 4.5% (saltier than seawater).
Sigurdson’s article reminds us where most of that chloride is coming from -- road salt. In fact, the Nine Mile Creek study found a high correlation between the number of snowfall days per winter, and the associated elevation in chloride levels in the water, with the highest chloride spikes occurring with the spring snowmelt.
And, it’s not just small water bodies in urban environments seeing increases in salinity. The average chloride concentration in the Great Lakes of 0.12% is increasing by 0.001% every year. That may not seem like a huge increase, but when you consider that the Great Lakes contain 22% of the world’s fresh surface water, that’s a lot of salt.
But, like most environmental issues, we can’t just blame the problem on one source. In addition to road and sidewalk salt, chloride also comes from water softeners, fertilizer application, and industrial effluent.
So, let’s keep the salt on the fries, and out of the lakes and rivers. Use the right amount of ice melt product, set your water softener to the proper recharge rate, use the right amount of fertilizer, and support businesses with a commitment to environmentally sustainable practices.
And if you can’t finish your fries, share them with me.