Envisioning a less salty future

Have you ever seen the intricate dance of a convoy of snow plows clearing a highway after a winter storm? You may have experienced it in real-time trapped behind the armada, tapping your fingers on the steering wheel as you nervously wonder whether you’ll make your 9 am work meeting, but if you take a look from the air, it’s actually quite amazing.

The video needs a soundtrack for such a well-timed plow dance. Major kudos to the driver of the plow on the shoulder of the road.

Winter in Minnesota (and the Midwest) is definitely a different beast. When I first moved to Minnesota over 10 years ago, my winter chops were nonexistent. Coming from the Pacific Northwest, my skills were limited to being able to function weeks without regular sunlight and confidently telling you the difference between a ‘drizzle’ and a ‘mist’. But when it came to winter, my experience was to get home as fast as possible before any significant snowfall, hunker down, and watch society come to a halt for a day or two to either let things melt or allow time for the limited number of snow plows to dig us out.

But in Minnesota, you don’t stop. You can’t stop. Because if you did, it’d be weeks or months before people would be able to go about their normal business. You gotta get on with living. And while snow plows are a significant part of our snow management strategy, we also rely heavily on that cubic mineral known as salt to manage our slippery roads, sidewalks, and parking lots.

I honestly didn’t know about the extent of the salt used to de-ice roads, sidewalks, and parking lots when I moved here. I thought the use of salt was magic – this amazing substance that enables us to just keep doing our thing without needing to put chains on our vehicle tires. I got used to seeing trucks spray salt on roads and hearing the crunch of chunky salt crystals under my boots on sidewalks.

But then, I started learning about salt’s cost to our environment – our salt use is leading to chloride levels in our rivers and streams that are considered dangerous for aquatic life. On average, the Twin Cities uses 365,000 tons of road salt each year, and a study by the University of Minnesota showed that up to 78% of that salt travels and remains in our groundwater and local rivers, lakes, and wetlands. In recent years, studies have shown that over 20% of monitoring wells in the Twin Cities metro area have chloride levels that exceed the EPA drinking water guidelines. Fifty-four Minnesota lakes and streams have chloride levels too high to meet the standard designed to protect fish and other aquatic life (and another 75 lakes and streams are close to also exceeding that standard).

The MPCA has a map viewer specifically for chloride monitoring efforts across the state. While those blue dots indicate the majority of tested waters are not impaired for chloride at this point, the number of red and yellow spots is continuing to grow. Click to access the map.

Once water is polluted with chloride, it can be removed by reverse osmosis, which at the scale we would need to address our growing salty water problem, is considered quite cost-prohibitive (think massive filtration plants). So once our water is polluted with chloride, it’s polluted. Stop. End game.

Suddenly hearing that crunch of salt under one’s feet has a far more sinister connotation to it.

We need to go on a salt diet. We need to find a better balance.

There have been some amazing strides forward in helping us reduce our dependence on salt, mainly in recognizing that we are very inefficient in using it – we generally grossly oversalt. If you see salt on the road or on sidewalks after the snow/ice has melted, that surface was oversalted. Connie Fortin of Bolton & Menk, Inc. (formerly Fortin Consulting) has spent the last two decades working with winter maintenance workers to develop best management practices for salting our winter surfaces. She helped put together the Minnesota Pollution Control Agency’s Smart Salt Training workshops, which are open to any operator who salts surfaces – be it on state, county, or local roads or private contractors who salt parking lots and sidewalks. Overall, organizations have been able to reduce their salt use 30-70% after participating in the five-hour workshops.

There have also been campaigns to raise general public awareness of smart salting practices – mostly to avoid using salt as much as possible by shoveling first, but if absolutely needed, a mug of salt is sufficient for managing 250 square feet of driveway or generally 10 sidewalk squares. Instead of haphazardly chunking handfuls of salt on the ground, try to space out the salt grains so there’s roughly 3 inches between pieces.

And while we may have visually gotten used to seeing salt and think it equates to safety from slips and falls, we need to start thinking of where it goes after meltwater washes it to the embankment of the road or a storm drain. More salt does not equal more or sustained melting – it just means more chloride in our environment.

We can also start examining what we can do to reduce the need for salt in the first place – we generally plan developments and infrastructure as it pertains to managing stormwater from rain events – but why not also incorporate planning for how to manage snow and meltwater to minimize ice formation in the winter? Fortin and her team at Bolton & Menk recently started putting together a package of materials and trainings with guidance to do just that, using stories and experiences they’ve collected from winter maintenance workers about conditions that lead to needing to salt specific sites repeatedly. Can building entrances and access points be designed in a way that maximizes the amount of sunlight to reduce ice formation? Can we be strategic with how we place boulevard trees or landscaping so they don’t shade out areas that get lots of foot traffic in the winter? How can we better determine where to store plowed or shoveled snow in parking lots so its meltwater doesn’t flow and potentially again freeze in areas where cars or people might slip?

It’s an intriguing line of thought, and it’s a necessary one if we want to help halt this growing salt water trend in the Midwest. While there are many times I envision a warm sunny beach on the ocean during these long cold months, I have no wish to have the salt water here.

Here’s a great informational video about best salt practices!