It’s safe to say this winter has been a mess all around. The Central US is frozen; Madrid recently dug out of a fifty-year-record-breaking snowfall. The mid-Atlantic US just got hit with another bought of…something. The other day, I was stuck behind a brine truck; after being stuck behind a salt truck scouting for ice patches. Then passed four additional plows. All while driving primarily backcountry roads headed to the pharmacy! To be fair to the county, the route I was traveling is used heavily by the local fire department. Still, this aggressive response got me thinking about the consequences of snow removal and the impact on the environment.
Clearing the mess
Another spark for this post came from a phone call a few nights ago with my mom. She heard on the news that the brine used in snow removal gets mixed with beet juice. My mom, a big fan of beets, got a kick out of this. After some research, I found that Maryland doesn’t use any additives to their brine, but other places do.
The brine squirted on roads before a storm is a 20% solution of sodium chloride and water. Many municipalities mix that solution with additives to essentially stretch the salt. They also claim it’s to reduce the environmental impact. Toronto and Calgary were the first to get credit for beet juice, but other cities followed. Beet juice lowers the salt concentration to about 12%, and it is less corrosive.
Memphis, Tennessee adds potato juice, and the Wisconsin DOT mixes cheese brine with the salt solution. Because of course they would. Cheese brine is a bi-product of dairy farms; the farms give the stuff away. Argentina adds wine bi-products to their brine.
The wet brine mixture is also used to coat the solid rock salt before it is spread from the trucks. The brine reduces the bounce rate of the salt when it hits the road, wasting less material.
Areas of Western Maryland apply a sand/gravel mixture in the higher elevations. I’ve always heard Pennsylvania road crews drop a sand/cinder mixture, but I couldn’t find much to back that up. Sand and gravel are commonly mixed with salt in mountainous terrain to help with traction. There are issues here, as we’ll see later.
Japan, always innovative
Northern Japan earned the nickname “Japanese Alps” because of the amount of snowfall they see each year, in addition to the high density of ski resorts. Municipalities estimate moving an average of 575 cm (226 in. /18.8 ft!) of snow per year.
Some towns on Honshu Island employ a system of pipes called “Shosetsu pipes.” Pipes are laid just under the surface of the roadways. Warmer groundwater flows over the roads melting the snow. The whole process is dependent on the groundwater remaining warmer than the ambient temperature. This is possible because of the geography of Northern Japan.
By far, the most common method of snow removal is good old-fashioned manual clearing…plowing, shoveling, blowing…etc. The application of brine theoretically helps the process. Brine when applied correctly, keeps the snow and sleet from freezing to the roadways, and the mess is more efficiently cleared.
Disposing of the mess
Ordinarily, the winters here don’t drop enough snow on the mid-Atlantic to worry about where to put the mounds. One exception would January of 2016 (image below.) We had about two feet or so of snow. The parking lots in town began to resemble scale models of the Rocky Mountains.
A prominent businessman in the area “allowed” the county and private companies to pile snow on three or four of the lots of his empty businesses. It was fun to drive by these lots in April and compare the charred little mounds to peaks they once were.
They’re called snow dumps in Canada, snow farms in Massachusetts. They are environmentally approved places to dispose of massive amounts of snow. The Saint-Michel snow dump in Quebec is probably one of the best known because of the glacier of snow that lasted into July. The design of these locations specifically minimizes the runoff of chemicals, solids, and excessive amounts of freshwater into surrounding waterways.
Along with water pipes in the roadways of Japanese towns, some places utilize a roadside ditch system. Ditches dug along the roadside are supplied with a continuous stream of groundwater. Residents shovel their mounds or clear their roofs into these ditches. The warmer water melts the snow, much like the pipes, flushing the snow into the waterways. I guess this snow isn’t treated with anything so freshwater influx isn’t an issue.
The problem with the ditch system becomes evident when snowfall is heavy. Residents have to cooperate and take turns to avoid clogging the ditches. Issues also arise when the terrain isn’t properly sloped, or worse, when a high water draw causes ground subsidence.
Environmental impact of the mess
Here’s where we look at how bad all of this is for the environment. There are tons of studies investigating the effects of salts, chemicals, and excessive freshwater influx to the surrounding ecosystems. It’s a challenge to whittle down the best examples!
A few years ago the local news began running a series of reports focused on the plight of some rather well-to-do residents living in one of the highest income areas of the state. They blamed their county for excessively salting their roads and “poisoning” their wells.
One woman complained to reporters claiming the county was applying 300% more salt than county average (not sure where her numbers came from) to her road and her well test readings were 20% higher (for what, I don’t know) than safe levels. To her credit (sort of), a Swedish study did suggest road salting contributed to a 40% increase in the Chlorine content of shallow (35 ft or less) wells close to roadways.
Soil pH increases as the meltwater percolates through the topsoil. Heavy metals like lead get trapped in the ground along with some remaining Sodium and Chloride. A 1980 study indicated the presence of contaminants during the summer months. They suggested that the influence of winter snow removal can linger throughout the year.
I did not realize it was technically illegal to dispose of snow in waterways, but it makes complete sense. The snow dumps are areas that have specific designs to minimize the amount of solids impacting waterways. Sand and gravel application is limited to certain areas to ensure melt water from snow doesn’t lead to a buildup of sediment in tributaries. Those images of the “snow glacier” in Quebec are nifty, but did you notice all the plastic bags and assorted trash?
Not the Green way, too?!
Sadly, even beet juice may do some harm to the environment, particularly mayflies. A 2018 study suggested potassium-rich beet juice may contribute to increased stress on the bodies of mayfly larvae. More research needed, say researchers, but there appears to be a connection between regulatory stress and beet juice.
The take home
In a perfect natural world, we would allow the snow to melt in its own sweet time. Practically we can’t wait that long. We have to face the reality that humans need to interfere in the natural process, speed it up, and get back to life. Along with additives that are less harmful to the environment and specific dumping areas designed to hold more toxic chemicals, some places are using a technological approach.
Onboard GPS and weather forecasting apps directing plow drivers to the locations most critical, and interactive reporting systems allowing the public to inform crews of more affected areas may limit overuse of resources. Finding ways to convert the small-scale Japanese systems to large-scale city-sized endeavors is being investigated in some countries, too.
Now, I have to go shovel out my car and scoop the third layer of frozen nastiness from my driveway!!
