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https://stockdailydish.com/road-salt-runoff-threatens-us-canada-lakes-study/

Road salt runoff threatens US, Canada lakes: study

Salting of roads in winter helps drivers navigate snow and ice, but the runoff may be irreparably damaging freshwater lakes in the United States and Canada, researchers warned Monday.

Most of the 371 North American freshwater lakes in the US Northeast and Midwest and Ontario province are showing an increase in salinity from chloride runoff, according to a study published in the journal Proceedings of the National Academy of Sciences.

And if the trend continues it could doom aquatic life and reduce water quality, limiting the supply of drinking and irrigation water, the researchers said.

“The picture is sobering,” said lead author Hilary Dugan, a freshwater specialist at the University of Wisconsin-Madison.

“We compiled long-term data, and compared chloride concentrations in North American lakes and reservoirs to climate and land use patterns, with the goal of revealing whether, how, and why salinization is changing across broad geographic scales,” Dugan said in a statement.

“For lakes, small amounts of shoreline development translate into big salinization risks.”

Each lake studied was larger than four hectares (0.02 square mile) and had at least 10 years of chloride data.

The majority (284) of the lakes were located in the North American lakes region that includes 10 US states — Connecticut, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New York, Rhode Island, Vermont, and Wisconsin — as well as Ontario province.

The use of road salt to keep winter roads navigable has been rising since the 1940s. The researchers determined that each year, some 23 million metric tons of sodium chloride-based de-icer are applied to North American roads.

– Underestimated problem –

Much of that road salt washes into nearby water bodies, becoming a major source of chloride pollution to groundwater, streams, rivers and lakes.

To measure the quantities of road salt applied to roadways and other impervious surfaces, such as parking lots and sidewalks, the researchers evaluated road density and land cover within a 100- to 1,500-meter (0.06-0.09 mile) buffer around each of the study lakes.

Their findings were clear: roads and other impervious surfaces within 500 meters of a lake‘s shoreline were a strong predictor of elevated chloride concentrations in the water.

When the results of the study are extrapolated to all lakes in the North American lakes region, some 7,770 lakes may be at risk of rising salinity.

If the escalation in salinization continues, it said, many lakes will exceed in the next 50 years the aquatic life threshold criterion for chronic chloride exposure set by the US Environmental Protection Agency of 230 milligrams per liter.

According to the study, 14 lakes are expected to exceed the EPA standard by 2050, and 47 are on track to reach chloride concentrations of 100 milligrams/liter during the same time period.

“These results are likely an underestimation of the salinization problem, as a number of regions with heavy road-salt application, such as Quebec or the Maritime Provinces of Canada, had no long-term lake data available,” said co-author Flora Krivak-Tetley, a graduate student at Dartmouth College.

High chloride levels in lakes have been shown to alter the composition of fish, invertebrates, and the plankton that form the base of the aquatic food web.

That can reduce aquatic species and, in extreme cases, salinization can cause low oxygen conditions that smother aquatic life and reduce water quality, the study noted.

https://www.cbc.ca/news/canada/saskatoon/chemist-u-sask-snow-ice-1.5402583

As Canadians, we spend much of our time walking in a winter wonderland — yet one researcher at the University of Saskatchewan suggests we remain in the fog on snow and ice.

"It's exciting how little we know, in a way," said Tara Kahan. "Water is everywhere — it's so important to us, our lives, [but] when it's frozen, we don't know a lot about it."

Kahan, a professor at the University of Saskatchewan and the Canada Research Chair in Analytical Environmental Chemistry, has already spent more than a decade studying snow and ice, with an emphasis on what happens to pollutants trapped in a frozen state.

"We are used to pollution in lakes, rivers and stuff like that. All those pollutants can also end up in snow and ice, but what happens to them might be different," Kahan said.

Frozen fossil fuels 

Kahan is focused on pollutants that come from fossil fuels. She cites the example of benzene, which is sometimes found in high concentrations in snow and ice in places like gas stations, areas where hydraulic fracturing is used to search for oil and gas, or in busy shipping lanes.

In water, benzene does not react to sunlight. In ice, Kahan said it's a much different story — everything speeds up.

"This could be a really good thing," she said. "For example, if there's an oil spill and they're reacting really quickly with the sun shining on that snow, maybe it's cleaning [the pollutants] up.

"But on the other hand, they could be making something more toxic than what they started with, in which case this fast reaction would be bad. But we don't know yet."

Given Kahan's academic commitment to snow and ice you might imagine her trekking to icy and remote regions seeking out pristine snow to sample, but she admits she "doesn't like to be cold."

So her work is done methodically in a laboratory at the U of S — a lab full of ice cube trays.

Tip of the iceberg 

As Kahan slowly unlocks the chemical mysteries of snow and ice, the findings will be enhanced by existing computer models to hopefully predict what will happen to the pollutants she's studying. 

That should help to shed light on some very important questions, she says.

"We'll be able to just put this data into the model and then predict whether things are going to be good or bad — whether we need to worry, or whether we're really going to be remediating things and cleaning up the snow and ice."

Kahan said that improved understanding of the chemical reaction of pollutants trapped in snow and ice will become vital in trying to mitigate environmental damage in fragile ecosystems.

"The Arctic, actually, is a huge concern because as the winters warm … we're expecting a lot more shipping traffic. There's going to be a lot more pollution there."

While the fog may lift on the issue of pollutants, Kahan doesn't think her work in understanding all the mysteries of snow and ice will ever be done, because there are so many things she would like to explore — topics like "sea ice, or ice that has road salt in it," she said.

Kahan is all in on ice — as long as she doesn't have to spend too much time in the cold.

https://www.kitchenertoday.com/local-news/world-wildlife-fund-urging-ontarians-to-use-less-road-salt-1956722

The World Wildlife Fund is urging Ontarians to cut back on road salt. 

The environmental agency says road salt is a critical threat to freshwater and wildlife in the province. 

Elizabeth Hendriks is Vice-President of freshwater with WWF Canada, and appeared on The Mike Farwell Show on 570 NEWS on Tuesday. 

"In June of this past summer, we released a WWF Great Lakes Chloride Hot Spot Map. What we're looking at is an increasing trend of use. In the winter time, we can see the water has as much salt as oceans do in certain locations, so this is really damaging to our fresh water."

Hendriks said there's a lot of research looking at alternative methods.

"You hear about beet juice and different practices. At the scale that we need to use it though - with major highways and parking lots - we don't know that there's not other impacts. Some alternatives like beet juice can be used on a small scale, but we don't know about the larger impacts of those solutions."

Hendriks said the WWF is working with some municipalities, conservation authorities, and private property owners.

"We need to use less salt, but we don't want people to do that and then get a bunch of complaints. So it's really about knowing when to use salt .. beyond minus 10, road salt isn't that effective anymore. Shovelling is effective first, and distribution is really important. So we try to promote best practices with private industry, and working with the government to work on regulation that incentivize small business owners to use best practices as well."

According to the WWF, more than 7-million tonnes of road salt is used each winter by public road agencies in Canada. 

"It's cheap, it's easy to use, we know it's effective .. and a big part is, I don't think we knew the extent of the problem. When people hear about this issue, they really respond. They care about our fresh water, and so once we are aware of it, I think we'll really see people changing their actions."

Hendriks said this isn't a problem that can be fixed overnight.

"It will take time for a reduction. Even in the summer, we're seeing the impacts .. just because salt and the winter disappears, the salt isn't necessarily disappearing in a season. But ultimately the salt will dissipate as it works its way out of the environment."

To read more about the WWF's report, click here.

https://kitchener.ctvnews.ca/environmentalists-call-for-alternatives-to-salting-wintery-roads-1.4730652

KITCHENER -- What is the cost of salting roads – financially and environmentally?

The World Wildlife Fund is urging Ontarians to cut back on road salts that they say are a critical threat to freshwater and wildlife in the province.

“In winter we sometimes see ocean levels of salt,” said Elizabeth Hendriks, vice-president of fresh water for WWF Canada. “The levels we’re seeing are just outrageous and habitats can’t [handle] those levels of input.”

While the tri-cities follow salt management plans to reduce salt use and environmental expense, their  spending can still reach past the one million dollar mark.

The city of Cambridge spent $555,000 for 6,100 tonnes of salt this fall, while Kitchener spends an annual average of $1.3 million for 15,500 tonnes, and Waterloo spends $775,000 for 8,512 tonnes.

These totals do not account for any additional purchases of salt later in the winter or how much private contractors use.

Private contractor Clintar Kitchener uses an average of 5,000-6,000 tonnes per year and has been certified by the ‘Smart About Salt Council’.

“The whole goal is to recognize and try to develop practices that reduce the amount of salt used,” said Jim Maloney, owner of Cintar Kitchener. “How you do it, how much you apply, how often you do apply.”

He says they try to apply alternatives when they can.

“There are some liquid products, salt brine, there’s magnesium-based products,” said Maloney. “There are alternatives.”

WWF Canada commends Waterloo Region and municipalities for their efforts to reduce road salts, but says the long-term impacts of salt alternatives are still unknown.

They add that research is being done to find out what they are and how much money they can save.

https://www.cbc.ca/news/canada/toronto/road-salt-toronto-wwf-1.5388753

As Toronto deals with fluctuating winter weather, environmental advocates say excessive road salt is harming Ontario wildlife — and they're urge people to use less.

Salt used to melt icy roads and sidewalks can end up flowing into rivers, lakes and soil, creating dangerously salty environments for some freshwater plants and animals.

In certain areas during winter, "some of our rivers will have salt as high as oceans," said Elizabeth Hendriks, vice-president of freshwater with the World Wildlife Fund Canada. 

Some frog and salamander species can't breed in ponds with high salt volumes, said Environment Canada scientist Patricia Gillis, while rivers can become salty enough to kill young freshwater mussels.

"Impacts to even a few species can effect the whole ecosystem," said Gillis in an email.

Many people tend to use too much salt, said Hendriks, who previously said a small pill bottle worth of road salt is all you need to melt a city sidewalk slab.

"People tend to lather road salt on the ice," said Angela Murphy, manager with Ryerson Urban Water.

"It's really not necessary."

The WWF is working with Ryerson University to use less salt on campus.

In a pilot program last year, Murphy says they used six fewer tonnes of slat by spraying a mixture of slat and water called brine in four test locations prior to snow and freezing rain.

"It was just as effective," says Murphy, who says Ryerson made the brine in-house and it did not hurt public safety.

"There was no increase in liability, no increase in complaints...there's really no need for people to apply so much road salt."

There team is scaling up the project this winter, Murphy said, and studying the impact of using brine in place of road salt in certain city areas.

City uses 130, tones of road salt

The city of Toronto uses more than 130,000 tonnes of road salt each winter, as well as brine and some salt alternatives.. 

However, City of Toronto spokesperson Eric Holmes said salt is the most cost effective and efficient way to clear ice from roadways.

The city has to balance negative environmental impacts, he said, but their focus is on public safety.

The city implemented a salt management plan in 2002 to reduce salt use, Holmes said, which reduce salt usage 15 per cent in its the first 15 years.

They also put down salt brine before a storm, he said, and city trucks use automated equipment to determine where to spread salt based on road temperature.

Last year they also used beet juice a few times, Holmes said. But while it works in colder temperatures than road salt, he said, beet juice is harder to get and more expensive.

Although safety is critical, Hendriks said both public roadways and private properties contribute to over-salting in Ontario's lakes and rivers.

She points to information programs like "Smart About Salt," where contractors and property owners can learn ways to reduce their salt usage.

"Everything we do on the land feeds into our river system and into [Lake Ontario]," Hendriks said.

"What we do on the land and on our roads matters."

https://www.cbc.ca/news/canada/kitchener-waterloo/salt-use-waterloo-region-1.5381157

According to information from the the cities of Waterloo, Kitchener, Cambridge and the Region of Waterloo, a combined 43,000 tonnes of salt will be used to keep roads ice-free this winter. 

All that salt costs $3.8 million each year.

Responsibility for salting and snow removal is split between the cities and the regional government. Each has its own fleet of trucks, de-icing methods, and salt purchase price.

Salt by the numbers

Kitchener buys the most salt among the four governments, but their purchase price per tonne is by far the least. They pay $1.3 million annually for 15,500 tonnes. While the others in the region pay about $90 a tonne, Kitchener pays $83. 

The eight per cent difference adds up to significant revenue savings. Were Kitchener to pay the same price as the other governments, their salt would cost an additional $108,000 dollars per year. 

They spread an average 13 tonnes of salt on each kilometre of road they are responsible for clearing. 

Cambridge uses the least amount of salt on its roads, averaging only five tonnes for each kilometre. They also purchase the least salt, spending $600,000 on 6,500 tonnes annually. 

A spokesperson from Cambridge noted that the city receives significantly less snowfall than other municipalities in the region. 

No regulations for parking lots, sidewalks

That 43,000 tonnes is likely only half of the total salt being used in the Waterloo region says Claire Oswald, associate professor of geography and environmental science at Ryerson University. 

"Double that, and maybe add a bit more, and then you would have what is actually going on to the landscape," she said. 

According to Oswald, there are regulations on how much salt should be put on government roads, but those regulations don't exist for parking lots, sidewalks and other private spaces.

Over-salting comes from public expectations and liability concerns, she said.

Paul Johnson, operations manager for Wellington County, makes the same argument.

"I would say that most contractors out there will get a lawsuit a season, at least. That's per site," he said. 

"It depends on how big they are, they might have 60, 70, 80, maybe 100 or more sites that they maintain and so, the potential is quite great that they'll get a lawsuit." 

Health and environmental impacts

Eventually, that salt makes its way off the roads and into the environment says Eric Hodgins, manager of hydrogeology and source water at the Region of Waterloo. 

"We see increasing sodium and chloride levels in pretty much every single one of our wells. The concentrations are increasing to the extent that they exceed, in many cases, the Ontario drinking water standard, for either sodium or chloride," he said. 

Elevated salt levels in lakes and streams also have a detrimental effect on the smaller organisms living in them says Derek Gray, a professor of Biology at Wilfrid Laurier University.

He added that these bugs and plankton end up passing the salt up the food chain to larger animals such as fish and birds.

Cutting back

Over the last few years, local governments have moved to reduce their salt use. 

They've employed computerized spreaders that control how much salt is put down depending on the speed of the vehicle.

Many municipalities also pre-wet the salt, making it sticky and less likely to bounce off the road when applied.

There are also pre-storm brine sprays used by some municipalities, Eric Hodgins said. They make snow removal easier by preventing it from binding to the road in the first place. 

Though salt use changes from year to year depending on weather, a spokesperson for the City of Waterloo said they cut their salt usage by 6,000 tonnes between 2013 and 2017. 

https://toronto.ctvnews.ca/slip-and-fall-accidents-leave-snow-plow-operators-out-in-the-cold-1.4704062

TORONTO -- Contractors in the snow removal business say an increase in “slip and fall” accidents is causing insurance premiums for their business to skyrocket.

Dave Fraser runs DHF Contracting in Oshawa and has 20 employees who clear snow for commercial properties and school boards.

“Insurance companies are canceling us,” Fraser said. “They don't want us anymore and if they are taking us on are rates are going up astronomically. It’s forcing us out of business."

Fraser said that because there is one open slip and fall claim against his company, his insurance premiums went up almost 400 per cent.

“My insurance was $16,000 last year. This year my current quote is $60,000 for the same coverage," said Fraser.

Jeanette Hiddink also has a snow removal business. She says her premiums jumped $10,000 this fall. even without a claim.

“It makes you feel you're not going to be able to run your business and you’re not going to be able to employ your people and all my people have families. They need the money. They need the job,” Hiddink said.

Just a single slip and fall accident can lead to a six-figure payout. Jamie Cardella is the president of HUB Markham, which is the largest provider of snow removal insurance policies in Ontario. He said that even when snow removal operators do a great job removing snow, ice and salting parking lots, it can be difficult to keep up with winter conditions.

“You could clean a lot and the lot could have snow on it again 40 minutes later. Someone could slip on the ice or snow and they're (the snow removal contractor) getting brought into a lawsuit."

While municipalities, towns and cities have a 10-day statute of limitations on slip and fall claims, a person has two years to file a claim against a snow removal contractor. The industry wants that reduced to 10 days as well.

Cardella’s advice to snow removal contractors is to review their contracts and insurance policies carefully.

“They should be looking at their contracts, working with their broker and trying to get the best language they can possible to try and avoid these liabilities," Cardella said.

Fraser said rising insurance premiums means eventually everyone will have to pay more.

“At the end of the day this hurts the consumer because these costs have to be passed down and the consumer is the end user. They are going to have to pay" said Fraser.

Rising rates are also affecting snow plow operators who do residential driveways. There is a concern some may be clearing snow without insurance coverage because they can't afford to pay for the premiums.

https://www.utoronto.ca/news/road-salt-taking-its-toll-insects-toronto-area-u-t-researchers-find

It may help keep your car on the road in the winter, but research from the University of Toronto suggests that road salt is creating problems for wildlife.

Researchers from the lab of Shannon McCauley, an associate professor of biology at U of T Mississauga, investigated the impact of road salt exposure on larvae of Anax junius dragonflies. The results, published in the journal Frontiers of Ecology and Evolution, show that long-term exposure to high levels of salinity suppress the immune response of aquatic insects, negatively impacting their ability to fight infections and recover from injuries.

Known as “green darners,” Anax junius dragonflies are one of the most common and abundant species in North America. Long and thin, they can grow to a length of 76 mm and are fierce and voracious predators. 

“They eat everything, including each other, other dragonflies, mosquitos and zooplankton,” says Rosalind Murray, a post-doctoral researcher in the McCauley Lab who co-authored the study with McCauley and undergraduate biology student Racquelle Mangahas. “In a fishless pond, Anax junius are top predators that shape the aquatic ecosystem.

“We don’t know much about how macro invertebrates – larger insects – respond to salinity, and no one has ever looked at this particular species.” 

Murray notes that 2017 was a boom year for the insects, which were collected at U of T’s Koffler Scientific Reserve north of Toronto for the study. “It was a good opportunity to ask questions about what is happening to these top predators,” she says.

Salt enters aquatic environments in a number of ways. In colder climates, salt is spread liberally for traction on icy roads, parking lots and walking paths, where it can be washed into ponds, rivers and streams when the snow melts. In warmer locales, salt also enters the watershed through road gravel, agricultural applications and runoff from saltwater residential pools.

Previous research measured how much road salt might be lethal to aquatic populations, but Murray notes that many creatures may experience non-lethal salinity levels over different periods of time.

“Stagnant ponds might contain little pockets with higher salinity, and insects can move in and out of them so they may experience quick acute exposure,” she says. “They may not be experiencing salinity at a rate that is sustained enough to kill them. We wondered how salinity might be affecting animals in a non-lethal way.”

The researchers theorized that salinity might have an effect on the insects’ immune systems. To observe the potential effects of road salt on larval immune response, the researchers turned to melanin, a chemical that plays a role in wound healing. “When an insect has a wound, it sends melanin to encapsulate the foreign object or wound,” Murray says.

Dragonfly larvae were injected with a monofilament to mimic injury that might be caused by a parasite or other wound. The larvae were then placed into water with various levels of commercial road salt ranging from standard tap water with no salt added to solutions of one and three grams of salt per litre. The larvae were left in the solutions for periods ranging from one to 96 hours (four days), after which the researchers measured the amount of melanin deposited on the monofilaments.

“We found that the highest level salt treatment in longest-term exposure resulted in a significantly decreased immune response,” Murray says.

“Dragonflies are pretty robust, but at the longest period of the highest concentration, we saw that they are being affected by high concentrations of salt,” she says. “Our study exposed the insects for just four days, but animals may live for years in the same pond. A chronically salty environment, it could – and likely would – have a much stronger effect.”

Chronic exposure to salination could have other long-term implications for the insects and also for other creatures on the food chain. Additional research from the McCauley Lab indicates that exposure to road salt appears to negatively impact the appetite of adult dragonflies. “Our research shows a decrease in the number of mosquitos that they are eating, which could impact how many mosquitos are in our environment.”

“It’s a global problem that’s not specific to cold climates,” Murray says. “It is important to be aware of how much salt we are adding to the environment, and that it is having an effect.”

The research was supported the Natural Sciences and Engineering Research Council of Canada.

https://www.msn.com/en-ca/news/canada/judge-finds-homeowners-cant-be-found-liable-for-accidents-on-poorly-cleared-sidewalks/ar-BBXoRdV?ocid=spartanntp

When Darwin Der fell on a Burnaby, B.C. sidewalk in December 2017, he broke more than the carton of eggs he was carrying in his hand.

A combination of snow, rain, shovelling, salt, unfreezing and refreezing had turned the angled pavement cut into the curb for wheelchair access into a literal slippery slope.

But Der has faced a proverbial uphill battle trying to hold anyone responsible.

The latest blow came this week when a B.C. Supreme Court judge ruled that a pair of homeowners couldn't be found liable for attempts at clearing away snow that may have inadvertently made the sidewalk slipperier.

Justice Heather MacNaughton's ruling provides a window into the law around snow removal and the rights and responsibilities of citizens when it comes to clearing the sidewalks in front of their properties as the mercury dips.

Long story short: even if you fail to comply with a municipal bylaw requiring you to shovel and salt, you can't be found liable if someone slips because you failed to do so.

I immediately fell hard onto my back and neck

Der and his wife were walking home from a grocery store with a dozen eggs on Dec. 21, 2017 when the 76-year-old slipped on the corner of the sidewalk outside of a home belonging to Ang Zhao and Quanqiu Huang.

"As I stepped onto the sloped sidewalk just ahead of my wife, my feet slid out from underneath me and I immediately fell hard onto my back and neck," he wrote in an affidavit filed with the court.

"There is a gap in my memory after the fall, but when I regained some level of awareness, I could feel pain in my shoulder, neck and back, and I could not move."

The retiree has since required surgery to fuse his spine and suffers from some degree of paralysis.

Bylaw breach does not equal civil liability

Der initially sued Zhao, Huang and the City of Burnaby but later discontinued his action against the city.

He was also forced to acknowledge precedent that says that a breach of the city's bylaw requiring "an owner or occupier of property abutting a municipal sidewalk to clear it of ice and snow by 10 a.m. every day" does not create civil liability against the property owner when it comes to users of the sidewalk.

A 2000 ruling in Ontario's Court of Appeal noted that municipal governments across the country "enlist their own residents in the snow-clearing enterprise" and that accidents take place just as regularly.

But those judges found that "the snow and ice accumulating on public sidewalks are the legal responsibility of the municipality" unless an owner assumes responsibility for the space or if poor conditions on their land flow onto the sidewalk, making the public property hazardous.

That left Der trying to claim that Zhao and Huang had "created a hazardous slippery sidewalk that was not visible to a reasonable pedestrian" when they tried to clear the sidewalk prior to the accident.

'Imperative' to follow clearing with de-icing

Zhao and Huang moved into the home in front of the sidewalk on the day Der fell.

Zhao said he had shoveled the sidewalk in previous days in order to comply with the city's bylaws. And Huang claimed she salted the sidewalk in the morning to make it safer for the movers.

But according to a report filed by accident reconstruction expert Tim Leggett, the classic Lower Mainland cycle of freezing and thawing likely left the bare sidewalk vulnerable to the kind of melting that later leads to black ice.

In fact, he said, that had the sidewalk not been shoveled, the snow might have provided some traction.

"It is imperative when performing any winter road maintenance activities to perform it thoroughly," wrote Leggett, an expert in winter road maintenance, friction and slippery slopes.

"In other words, if an effort is undertaken to remove the snow then it follows that an additional effort should be made to apply a de-icing chemical to remove any excess material left behind."

Policy nightmare?

The judge noted that Der wasn't claiming the couple's snow clearing attempts alone had created a "direct" hazard — rather that they should have foreseen that the weather might later turn their bare sidewalk into a skating rink.

MacNaughton said Der had failed to meet the burden of proof for that argument and finding otherwise could have huge policy consequences.

If "property owners who do not clear sidewalks abutting their properties have no legal responsibility for potential resulting danger on those sidewalks, but those who comply with municipal snow removal bylaws expose themselves to liability, the result would be that property owners would have an incentive not to make any efforts to comply with snow removal bylaws," the judge wrote.

"The potential loss of the assistance of private property owners in snow removal efforts out of fear of the potential legal ramifications would be likely to cause more danger than it would prevent."

https://www.rivertowns.net/sports/outdoors/4779797-Angie-Hong-column-As-snow-approaches-ways-to-reduce-salt-use-and-help-the-environment

When the City of Carthage fell at the end of the Third Punic War, 146 BC, victorious Romans pulled Phoenecian ships out of the harbor and set them on fire before moving through the city, house to house, rounding up and selling 50,000 people into slavery. Then they set the city on fire. As a final insult before they left, it is said that the Roman soldiers sprinkled salt upon the ground to ensure that nothing could ever grow there again.

During the 17th and 18th centuries, Spain and Portugal punished traitors within their empires by executing them and then pouring salt on their land. Closer to home, some say that Union soldiers salted the fields in Georgia during Gen. William Sherman’s infamous March to the Sea (though it’s not likely they used very much, since salt was a hot commodity during the American Civil War).

Throughout history, pouring salt on the land has symbolized a curse not only for current inhabitants, but also for future generations. Then, during the winter of 1941-42, New Hampshire became the first state in the U.S. to apply salt to roads to help melt snow and ice more quickly. The U.S. used a total of 5,000 pounds of road salt that year. After World War II, road salt became more common. One million tons of salt were used in 1955, and 10 million in 1972. By 2017, local, state and federal highway departments were applying 19.8 million tons of salt every year to roads across the nation.

Whose future do we seek to curse?

Though the Roman and Union soldiers’ salting of the earth may have been mostly symbolic, our modern communities face the very real risk of suffering unintended consequences from using road salt, year after year. There is currently no practical technology for removing salt from our surface and groundwater resources and soil once it is there, so the only solution is to use less salt and hope that it doesn’t build up too quickly.

In Minnesota, 50 lakes and streams have already been contaminated by too much salt and another 120 are near the threshold for impairment. Recent research reported in the Proceedings of the National Academy of Sciences suggests that chloride concentrations are increasing in roughly one-third of all lakes in the northern U.S and Canada. Even the groundwater we drink is at risk. Almost 30% of shallow wells in the Twin Cities metro area have been found to have chloride concentrations above the recommended level for drinking water.

We all value our safety when driving in winter weather, but clean water and healthy soils are vital to our long-term survival as well. Here are five suggestions from local experts on how each of us can help:

1. Drive slower and wear appropriate shoes when it’s snowy and icy outside. This helps to support road maintenance crews, as well as large parking lot owners, in their efforts to reduce salt use.

2. Use less salt on your own driveway and sidewalk. One pound of salt (one heaping coffee mug) is enough to clear a 20-fo

   1. ot driveway or 10 sidewalk squares (250 square feet). Always shovel before using salt.

   2. Skip the salt when it is colder than 15 degrees. Salt works by lowering the melting temperature of ice so that it melts when the temperature is below freezing (32 degrees). However, traditional road salt (sodium chloride) doesn’t work when it’s colder than 15 degrees, so it is a waste of time and money to put down salt on very cold days. Magnesium chloride and calcium chloride work at colder temperatures (minus-10 degrees and minus-20 degrees, respectively) but can be more expensive.

   3. Sweep up and reuse leftover salt after the ice melts.

   4. Stop using your water softener if your water hardness is less than 120 milligrams per liter CaCO3. If you do need a water softener, switch from a timer-based to a demand-based system and install a bypass for your outside spigot so that you aren’t softening water for irrigation.

   Learn more about chloride and its impact on Minnesota water at www.pca.state.mn.us/water/chloride-salts.