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Accumulation of de-icing salts in lakes threatens those who live there – The Nizh Times

The accumulation of de-icing salts in the lakes threatens those who live there

Canada dumps millions of tons of de-icing salts on the roads each year and this causes salt pollution which can become toxic for certain organisms in fresh water. An article by Marie-Pier Hébert, post-doctoral fellow at the University of Vermont and UQAC.

ANALYSIS – Like many countries with cold winters, Canada sprays millions of tonnes of de-icing salt on the roads every year. Although we no longer see them under our feet in the spring, road salts do not disappear by magic: they dissolve, run off and accumulate (in part) in bodies of water.

Saline pollution can, however, quickly become toxic to certain freshwater organisms.

Certain species of microscopic animals, such as crustacean zooplankton (including the famous “water fleas”), can be sensitive to the increase in salinity in their environment. The loss of these small aquatic grazers could lead to significant environmental consequences, such as the proliferation of algae (normally grazed by zooplankton) or the reduction of food intake for young fish.

As an aquatic ecologist, I study how freshwater ecosystems and organisms respond to global change. With colleagues from some twenty universities around the world, including a team from the interuniversity research group in limnology (GRIL) at UQAM and McGill University, I participated in a series of international studies in order to to better understand the response of freshwater plankton to salinization.

AN ENVIRONMENTAL ISSUE ON A GLOBAL SCALE

Often measured as chloride (an ion commonly found in salts), the salinity of many lakes, rivers, ponds and wetlands is gradually increasing due to human activities. The causes are multiple. Runoff from de-icing salts (such as sodium chloride) applied in winter can play a major role in colder regions, but other practices such as agricultural fertilizer application, mining, raising the sea ​​level or land deforestation also contribute to the salinization of fresh waters.

The catch is that once the salts infiltrate our freshwater supplies, it is difficult, if not impossible, to extract them. Chloride contamination can persist for decades. The accumulation of de-icing salts, for example, can, among other things, pose problems for the management of drinking water and the release of harmful substances into water bodies. In fact, the salinization of fresh waters today represents a global environmental issue.

LOSS OF ZOOPLANKTON AND ASSOCIATED CONSEQUENCES

To assess the plankton fragility threshold of large-scale lakes, our international research team coordinated to carry out the same study in experimental enclosures in 16 lakes in North America and Europe. Our research indicates that increased salinity can cause loss of biodiversity and high zooplankton mortality at chloride levels similar to those measured in lakes polluted by de-icing salts.

Similarly, in nearly half of the experimental sites in the study, the massive loss of grazing zooplankton allowed algae to proliferate. In lakes, algal blooms can reduce water clarity (which can, among other things, harm organisms living deeper) and compromise certain “services” provided by these ecosystems, such as the quality of drinking water. , fisheries or recreational activities. In other words, the sensitivity of zooplankton to salt pollution can create a domino effect on other links in the aquatic food chain, thus destabilizing the ecological balance of lakes and harming their health.

These research results reinforce the conclusions drawn from other studies, but on a larger scale. Most studies on the subject focus on a single body of water or on model species in the laboratory. By joining forces with researchers elsewhere in the world, this collective effort has made it possible to show that a multitude of zooplankton species commonly found in lakes are sensitive to salinization, even if the environmental conditions differ.

As in many areas of science, there are always certain limits to what can be concluded from a study. That said, when you get the same results repeatedly and in multiple places, you can start thinking about the next step: the application of research findings and sociopolitical issues.

APPEALS TO PUBLIC AUTHORITIES

An important observation resulting from the work: the concentrations of chloride that can cause the mortality of 50% of zooplankton are often lower than the threshold concentrations established by government directives. In other words, whether in Canada, the United States or several places in the European Union, current water quality regulations are not stringent enough to protect lakes from pollution by salt.

In their natural state, freshwater ecosystems contain very little chloride; say, usually less than 20 mg Cl–/L. The threshold concentration considered safe for aquatic life in Canada is 120 mg Cl–/L, while in the United States it is 230 mg Cl–/L (about one or two tablespoons (s) of table salt in a bucket of fresh water).

Although adverse effects (especially on zooplankton) may occur below these chloride concentrations, one might still believe that the more conservative guidelines in Canada are safer. But it would still be necessary for these maximum thresholds to be maintained. This is not always the case, as the World Wildlife Fund of Canada (WWF-Canada) reminds us. In fact, chloride levels in lakes polluted by de-icing salts can reach several hundred, and sometimes even thousands, of mg/L.

Every winter, more than five million tonnes of salt are dumped on Canadian roads, pavements and parking lots; the metropolises in the east of the country, such as Montreal and Toronto, can spread nearly 150,000 tonnes on their own. The researchers call for reducing the application of road salts and considering alternative options. A recent study has also suggested some practices to improve management, such as the use of brine-based liquids to reduce the amount of salt applied. One thing is certain, it seems to have become imperative to develop dialogue with decision-makers and political leaders in order to ensure road safety while protecting environmental health.

Road salt is terrible for lakes and streams. Minnesota may have a solution | Grist

Environmental activist Sue Nissen wears a teaspoon on a string around her neck, which she likes to hand out to lawmakers during hearings in the Minnesota state legislature. That’s because one teaspoon of salt is enough to pollute five gallons of water, making it inhospitable for life. 

Road crews dump more than 20 million metric tons of salt on U.S. roads each winter to keep them free of ice and snow – an almost unfathomable number of teaspoons. Now, Nissen’s organization, Stop Over Salting, is pushing for Minnesota to pass a bill to reduce that figure by helping applicators learn how to use less of it — a technique called “smart salting.”

The reason, she said, is because the state’s freshwater bodies are in a crisis: 54 lakes and streams are “impaired” by high salt concentrations, meaning they fail to meet federal water quality standards, while dozens of others are drawing closer to that tipping point, according to the Minnesota Pollution Control Agency. But environmental activists and scientists argue that it’s possible to maintain winter safety while reducing the amount of salt spread on streets and highways.

“There are solutions,” Nissen told Grist. “We can still have our winter mobility and be safe … with less salt.”

Road salt, which works by lowering the melting point of ice, is cheap and effective, reducing car accidents by up to 85 percent. But aside from corroding metal and concrete — leading to an estimated $5 billion worth of damages each year — it also ends up in rivers and lakes, where it has toxic effects on aquatic life. In January, researchers from the United States and Canada found that even salt concentrations below the threshold considered “safe” by governments were causing severe damage to organisms.

Warnings about the effects of road salt on freshwater bodies and ecosystems first started in the 1970s, said Bill Hintz, the study’s lead author and an environmental scientist at the University of Toledo in Ohio. But salt use has tripled since then. Now, with climate change encouraging excessive salting by making winter storms more unpredictable, officials in states like Minnesota are starting to realize the magnitude of the problem. 

The Minnesota bill, if it passes, would be one of the first state laws to encourage “smart salting,” a way to reduce road salt use while still maintaining winter safety. New Hampshire passed a similar law in 2013, while Wisconsin also has  a “salt wise” training program. In New York, the Adirondack Road Salt Reduction Task Force launched a three-year pilot program this month to reduce freshwater salt contamination. 

The concept of smart salting encompasses a range of technologies and techniques. Brining involves laying down a liquid mixture of salt before a storm, which prevents ice from sticking and reduces the need for repetitive salting. It also includes applicators learning how to calibrate their equipment to know how much salt they’re using in the first place, as well as when to stop salting (below 15 degrees Fahrenheit, for example, salt is much less effective). Minnesota has been training applicators in these techniques since 2005, but under the new bill, certified “smart salters” would be protected from liability, preventing them from being sued for slip-and-fall accidents. 

Nissen hopes that this protection will encourage more private applicators to be certified in smart salting practices, which are not only better for the environment but help save money on salt. But convincing them is a challenge, she said, because people have come to associate the sight of salt with winter safety. “If anybody calls in and says, ‘I don’t see enough salt,’” she said, “they call the applicator and say ‘get out there and put more salt down.’”

This overreliance on road salt has severe environmental consequences. The most common kind used for de-icing is sodium chloride — rock salt — but calcium and magnesium chlorides are sometimes used for colder weather. Once it enters a body of water, salt is almost impossible to remove, requiring expensive and energy-intensive processes like reverse osmosis. Chloride, in particular, binds tightly to water molecules, and can be highly toxic to organisms like fish, amphibians, and microscopic zooplankton, which form the basis of the food chain in a lake or river. 

If the zooplankton die off, Hintz said, it can trigger a chain reaction that allows algae to flourish, causing toxic blooms and affecting native fish species that can’t survive in murky waters. That should trouble recreational fishers everywhere, he said, but salt contamination has also made it into drinking water, particularly in areas where people rely on deep wells to reach groundwater. In the Adirondacks in upstate New York, a 2019 study found that 64 percent of wells tested for sodium exceeded federal limits — which can be particularly dangerous for people with high blood pressure or others on sodium-restricted diets. 

This makes salt-reduction programs like Minnesota’s crucial, Hintz said, to “flatten the curve” of freshwater salt concentrations. “Best management practices are critically important right now,” Hintz said. 

But reducing salt use will only slow down the crisis, not stop it, Hintz warned. Salt that’s already been deposited might take years to show up in groundwater, and how much can be “safely” added without permanently damaging an ecosystem is an “open question,” he said. And non-salt alternatives, like sand or even beet juice, can come with their own problems, silting up rivers or introducing nutrients into ecosystems that can lead to algal blooms. 

Some cities have opted for proactive solutions — preventing snow and ice from building up in the first place, rather than melting it with salt once it’s already a problem. Since 1988, the town of Holland, Michigan, has invested in a “snowmelt” system, which uses pre-heated water from a nearby power plant to warm sidewalks and roads through a network of pipes underneath the surface, eliminating the need for salting. But solutions like this one are expensive and labor-intensive, said Amy Sasamoto, an official with the city’s downtown development district. The town spent over $1 million to install the first 250,000 square feet of underground tubing, and the system still only encompasses a few streets in Holland’s main downtown shopping area, although Sasamoto said it could expand along with future development.

These solutions may not be scalable to something like a four-lane highway, said Xianming Shi, an engineer and the ​​director of the National Center for Transportation Infrastructure Durability & Life-Extension at Washington State University. Shi studies how “connected infrastructure,” such as cars tapped into an information-sharing network, can increase winter road safety. For example, sharing real-time information about road conditions can help road maintenance crews know how much salt to use, reducing oversalting. 

But even improved technology and data-sharing won’t be enough, Shi said, to stop the flow of salt. Instead, it’s going to be crucial to encourage safer winter driving habits — like asking people to stay home during storms whenever possible, or to drive more slowly even on a highway. 

“People’s mindset is more of this moment, like ‘I want to drive fast through the winter,’” Shi said. “They don’t realize that this has a hidden consequence.” 

Road Salt Pollution Levels Deemed Safe in U.S. and Canada May Not Protect Freshwater Ecosystems Enough | Smart News| Smithsonian Magazine

Using salt to clear icy roads may be an effective winter safety measure, but excess salty meltwater can wreak havoc on freshwater ecosystems and drinking water resources. 

In a new study, researchers show current water quality guidelines in North America and Europe are not enough to prevent dangerous levels of salinization. The findings were published last month in the Proceedings of the National Academy of Sciences. 

"Salt concentrations are rising in lakes and rivers across North America and Europe over recent decades due to road deicing," says University of California San Diego ecologist Jonathan Shurin, who was not involved in the study, to Science Alert's David Nield. "The study suggests that the levels considered safe need to be revised downward."

Previous research has shown salt leaching from agricultural and mining operations cause freshwater organisms, like zooplankton, to die off in alarming numbers. The cascading effect from the massive die-off can generate an enormous shift in the freshwater system's food web, reports Tara Yarlagadda for Inverse. 

In the new study, researchers conducted experiments at several different sites in the United States, Canada, and Europe. To observe the isolated effects of salination on zooplankton in a controlled environment, the team altered sodium chloride levels in 16 large tanks of lake water called mesocosms, which allow scientists to focus on specific factors more easily than they could at an actual lake, according to Inverse.

“With an experimental mesocosm approach, we can be more confident that we are indeed observing the effect of salt and not some other factor in the environment,” study author William Hintz, a freshwater ecologist at the University of Toledo, tells Inverse.

Even at thresholds of sodium chloride that were considered safe, researchers found a significant loss of zooplankton populations and an increase in algae, per Science Alert. The safety threshold for sodium chloride is 230 milligrams per liter of water in the U.S. and 120 milligrams per liter in Canada. At 73 percent of the test sites, half of the zooplankton populations died off in salinity conditions considered safe by both countries.

Zooplankton occupy almost all water bodies except rivers and streams. From oceans, lakes, and ponds, the tiny microorganisms are abundant. Most lakes will hold over 40 species of zooplankton and play a crucial and central role in freshwater food webs. Because the microorganisms are hold a central position in lake food webs, they can affect algal densities, water quality, fish production, and nutrient cycling. When salinization kills off zooplankton populations, it can affect fish growth rates and populations.

"Almost all fish species consume zooplankton when they are young and need zooplankton to grow and eventually become bigger fish," Hintz tells Inverse.

With fewer zooplankton, freshwater ecosystems are more prone to harsh algae blooms that affect water quality. Saltier freshwater also means less available drinking water. The team calls for policymakers to craft legislation that will lower approved sodium chloride concentrations to protect freshwater sources.

"We — as a society — need to recognize that salt pollution is a major ecological issue affecting our freshwater ecosystems," Hintz tells Inverse. "We all need fresh water."

Extensive Use of Salt to De-Ice Our Highways are Causing Damage to Freshwater Ecosystems | Nature World News

Recent study shows that widespread usage of salt is also harming aquatic habitats, aside the fact that humans have such a salt dilemma that isn't related to modern nutrition, although salt has been successful at dewatering our roads in the wintertime.

Seawater amounts judged acceptable by authorities in the United States, Canada, and Europe are insufficient to safeguard aquatic wildlife. The complexity and regular operation of these habitats are already seriously jeopardized.

Extensive Use of Salt Harms Freshwater Ecosystems

Experts compare rising solubility of salt in liquid to road salt, along with salt utilize in agricultural production, moreover researchers also want the political establishment to tighten its grip on the usage of sodium.

According to UC San Diego News Center, environmentalist Jonathan Shurin, salinity levels in streams and ponds throughout Northern America and Europe have risen in previous years as a result of road de-icing and findings in recent study states that the acceptable thresholds should be reduced accordingly.

Investigators carried out a series of tests at 16 different locations in the United States, Canada, Sweden, and Spain, observing the impact of rising tiers of table salt, which is amongst the most commonly used types of sodium in waterbodies.

Even at normal limits of chloride which is about 230 milligrams per liter in the United States and 120 milligrams for every liter bottle in Canada, there was a serious drop of zooplankton and a raise in phytoplankton, as per Science Alert.

Zooplankton is an important meal supply for fish larvae, and its elimination does have a significant impact. At salt detection limits endorsed in Canada and the United States, more than quarter of the zooplankton community died off at 73 % of the locations. And as zooplankton disappears, algae grow.

Also read: NASA's Curiosity Mars Rover Finds a 'Martian Flower'

The Result of Extensive Use of Sodium

Shelley Arnott a Queen's University biologist explained in a statement that more algae in the waterways might result in a drop in aquatic vegetation, which might also damage creatures dwelling on the bottom of bodies of water.

The elimination of zooplankton, which leads to increased algae, has the power to affect lakeside ecological systems in dimensions which might disrupt the functions bodies of water supply, specifically entertainment possibilities, potable water supply, and aquaculture.

The fact that experts conducted such comparable observation at 16 different locations with identical findings indicates that the dilemma is the same regardless of regional changes in geography, agricultural management, as well as hydraulic conductivity. Sodium may stay in natural waters for generations, that is why it is critical to prevent salt from accumulating in the beginning

Furthermore, as per to the authors, the advantages of sodium consumption, such as reducing road collision must be thoroughly assessed alongside the environmental consequences, especially if environment changes as a consequence of global warming.

"The findings of this investigation demonstrate that the concentrations of saltwater that harm habitats are lesser than usual assumed, with fish, algae, as well as other creatures potentially getting damaged at quantities typically encountered in the wild," Shurin adds.

These standards are followed by mass transit authorities that determine how much and when to use sodium to roadways to reduce frost. Experts and Authorities ought to impose stronger limitations on sodium contamination if we wish to maintain aquatic environment in the foreseeable.

The Trouble With Road Salt — And How It Reinforces Car Dependence – Streetsblog USA

If you live in a northern state, you may be pretty accustomed to views like the one above.

During winter storms, many northern climates use salt as a primary means of de-icing roads in the winter. Road salt is pretty inexpensive to purchase up front, but it’s actually quite damaging to our public infrastructure (roads, bridges), vehicles, and fresh water sources. Salt, or sodium chloride, is corrosive, suggesting that this inexpensive short-term fix to make our roads safer may be costing us more in the long run.

Our use of salt increased exponentially after World War II, with the rise of the suburbs. As people became reliant on cars to travel to work, driving through all weather conditions became crucial to the economy, and thus we saw salt being introduced as a major tool to control winter road slickness.

When commuters and truckers needed to travel in every condition, it became policy in many cities and towns that the roads would be cleared shortly after a storm. With more cars on the roads during slippery conditions, more collisions were prone to occur, so further solutions past a typical plow were sought out. A more recent study found that by dumping salt on our snowy and icy roads we reduce road collisions up to 87%.

But before our society revolved around the use of cars, when storms came and made roads unsafe, a majority of people simply accepted the pavement was not traversable and stayed home. If there wasn’t a way to travel by walking or by train, trips were delayed and people took the days off until plows could come through and the weather cleared. Those that needed to drive in dangerous conditions put snow chains on their cars, and local governments would spread sand and cinders to improve traction on the ice.

Although people might not have known this at the time, staying home for a few “snowed-in” days might ultimately be the better option for our towns’ financial resilience than our current habit of instantly clearing roads. Ostensibly, rock—or road—salt is inexpensive. It’s one of the reasons we rely on it so much, as the United States uses up to 20 million tons of salt per year to de-ice roads. Nevertheless, the United States Environmental Protection Agency (EPA) has estimated that using rock salt as a de-icer has cost us approximately $5 billion dollars in annual repairs to cars, trucks, roads, and bridges, because of the long-term damage it does to vehicles and infrastructure.

For those of us that live in colder northern climates, we all know that eventually after years of driving on salty roads, the bottoms of our cars will rust and erode. The chloride ions in salt have the ability to break down the protective oxide layer formed on the surface of some metals (including aluminum), and speed up the process of long-term damage. Not all pavement is created equal, but salt will shorten the lifespan of concrete and asphalt by accelerating the normal deterioration process through the freeze-thaw cycles in winter.

Even though road salt decreases the life expectancy of our infrastructure, in the Northern U.S. and Canada, it’s become a necessity to making our roads safe for driving in snowy winters. Typically, we cover our roads with halite, or rock salt (the same form of salt we sometimes use for french fries) once it’s been through a lengthy purification process.

Salt works by lowering the freezing point of water through a process called freezing point depression. Water needs to be at a temperature of 32 degrees Fahrenheit (0 degrees Celsius) to begin forming into ice. Essentially, once salt is added into the mix, water has to get a lot colder than it normally would to freeze. That’s how we get the ice-melting-effect when we sprinkle salt on our front porches.

Of course, inexpensive rock salt isn’t the perfect solution to de-icing. When temperatures drop below 20 degrees Fahrenheit, it can be too cold for sodium chloride to be effective on its own. That’s when you may see local public works and transportation departments adding other chemicals (salts) such as magnesium chloride or calcium chloride to their salt (sodium chloride) mixes.

Not only does sodium chloride contribute to the erosion of pavement and metal, once it washes away from the road, it leaches into the ground and can pollute our freshwater systems, causing a rise in sodium levels. And as of right now, we have no way to remove it. In 2018, a study of wells in Dutchess County, New York, found that the sodium concentration was much higher than the federal and state recommendations. They discovered levels as high as 860 milligrams per liter in some wells, while the general recommendation sits at 270 milligrams per liter.

Joseph Stromberg from the Smithsonian Magazine wrote, “As more and more of the U.S. becomes urbanized and suburbanized, and as a greater number of roads crisscross the landscape, the mounting piles of salt we dump on them may be getting to be a bigger problem than ever.”

Canada declared road salts as an environmental toxin in 2004, and they placed new guidelines on its use. Many local U.S. governments have searched for ways to at least reduce the use of road salts. Finding an alternative that eliminates the use of salt entirely is not so simple, though, as many of these alternatives have higher upfront costs. Other potential de-icing options that are at the same or lower price point of salt tend to not be as effective in breaking down icy roads.

Removing salt from our roads entirely may seem a daunting feat while we rely on cars for transportation, but perhaps we can reduce its use. Organizations and some local governments are focusing on spreading the right amount of salt for different conditions.

The Minnesota Pollution Control Agency, for instance, offers “Smart Salting” training to individuals and organizations. Their goal is to “provide the latest technologies, best practices and tools, and available resources to assist your organization to be effective and efficient in managing snow and ice.”

The Wisconsin Salt Wise Partnership works to educate maintenance professionals on how much salt is really needed to be effective. Even in our personal salt use, when maintaining our driveways and sidewalks, we tend to sprinkle more salt than we really need to effectively break down ice.

There’s also been discussions about pre-salting the road before a storm, a practice Rhode Island adopted in 2012 called Anti-Icing. A more obscure alternative applies beet and tomato juice as a solution to keep our roads from icing over. It may seem odd, but the use of a prickle brine is also said to help minimize salt runoff and potentially help reduce salt use.

Besides changing the way we dump salt on our roads, there are possible innovative solutions regarding the use of porous pavement. The EPA writes: “porous or permeable pavement allows standing water to seep through, removing water from roads that would normally go through freeze-thaw periods, thus preventing ice formation on the roads.”

Over the years, road salt has caused a lot of problems and damage to our infrastructure and natural environment. Changing the way we salt our roads may be a good immediate fix to help reduce the speed of corrosion, but to really save our infrastructure, we need to rethink the way we’ve built our towns and cities to revolve around the automobile. If we continue expanding our roads instead of focusing on maintaining what we’ve already got, it will only create more demand for de-icing measures. In other words, if we want to stop literally salting our own earth, then we must get away from our dependence on cars.

Valley News - Getting road salt down to a science (vnews.com)

CLAREMONT — The Claremont public works department has technology on its four newest trucks that calibrates salt distribution to road temperatures and air temperatures. Drivers prescribe just enough salt to keep the roads safe, and no more.

“We were using 350 pounds per lane mile; now it’s a little under 200 per lane mile,” said Ted Wadleigh, the city’s assistant director of public works. “We cut it by half.”

Reducing deicing salt is an important environmental goal. The salinity of freshwater ecosystems is climbing across the world as salt from fertilizers, mines and deicing highways washes into ponds, lakes and rivers. Salt concentrations far below the Environmental Protection Agency’s threshold still cause significant environmental damage in lakes and ponds, according to a new international study that Dartmouth contributed to.

The researchers concluded that there is an “immediate need to reassess current governmental thresholds to protect lakes from salinization.”

The EPA threshold for salt contamination is 230 milligrams of chloride per liter, while Canada’s is only 120 milligrams of chloride per liter. (Chloride is one of the two chemical components in rock salt). Even at Canada’s lower limit, researchers saw massive declines in zooplankton.

The Dartmouth researchers gathered water samples from Storrs Pond, Mascoma Lake, Boston Lot Lake and Goose Pond to recreate lake ecosystems in trash cans buried on the Dartmouth Organic Farm. They inched up the salt concentrations in the “mesocosms” each week. It only took days for zooplankton to suffer from high salt levels, said Jennifer Brentup, a former postdoctoral fellow at Dartmouth who conducted research for the study.

Zooplankton are crustaceans so small that they are hard to see with the naked eye. But they are a critical hub in the traffic network of lake ecosystems, said Kathryn Cottingham, a professor of biological sciences who led Dartmouth’s research team. Fish eat the zooplankton, and the zooplankton eat phytoplankton, also known as microalgae. The zooplankton are at center of the food chain, passing energy that the phytoplankton capture from the sun up the food chain. Without them, the more recognizable inhabitants of our lakes and rivers, such as trout and salmon, cannot survive.

“Basically, if you break the traffic network, then everything further up will fall apart,” Cottingham said.

As salt levels rise, negative impacts cascade through the ecosystem. Phytoplankton populations rose in nearly half of the study sites. In some sites, they formed a mat on the surface of the water, blocking light. Fish hunt by sight, and so they go hungry in the dark. The rapidly reproducing phytoplankton consume the oxygen, stifling fish.

The Dartmouth researchers said that lakes and ponds close to roads are most at risk. In 2021, the U.S. Geological Survey estimates that the U.S. consumed 54,000,000 metric tons of salt, and approximately 42% was used for highway deicing. Deicing salt damages more than the natural environment. It also seeps into groundwater, contaminating drinking water with a salty flavor and harming people with high blood pressure. Salt corrodes cars and infrastructure. The EPA estimates that the U.S. spends $5 billion dollars on annual repairs because of rock salt.

Climate change puts upward pressure on the amount of deicing salt New England needs to keep its highways safe. In New England, Brentup said that climate change is bringing more extreme winter precipitation and temperature swings. Rapid freeze-thaw cycles mean more ice on roads, and more salt.

Lakes and ponds in the region are suffering, and the problem is escalating each year. In 2008, New Hampshire listed 19 chloride-impaired water bodies that passed the EPA’s threshold. By 2020, that number climbed to 50.

“The chloride concentrations in New Hampshire’s lakes have been creeping steadily upwards since late ’80s and early ’90s,” Cottingham said. “Especially with interactions with global warming, we could be hitting thresholds that could cause big changes fast. How can we slow those things down?”

Cottingham emphasized that what we do on land affects our water. The New Hampshire Department of Environmental Services warns that neither evaporation nor chemical breakdown nor plants remove any significant amount of chloride from the environment. The salt we spread on our roads and sidewalks will almost all eventually end up in our water. The department emphasized that the only way to prevent more contamination is to limit how much salt we put down, without compromising safety.

New Hampshire has led a road salt reduction program that trains snow and ice management professionals to use as little deicing salt as possible. As of November 2020, the EPA credits the program with reducing road salt use by 20%.

Brentup listed off many ways we could reduce our dependence on deicing salt. Porous pavement absorbs the water that would otherwise freeze into a treacherous sheet of ice. “Brining” roads with a salt-water solution before a snow event requires much less salt than spreading rock salt. And some road crews are using biodegradable substances such as beet and pickle juice to slow ice formation and make the salt solution stick to roads rather than wash off.

Last year, the Claremont Public Works Department tried magnesium chloride mixed with molasses. The molasses limits rust on vehicles and sticks to the roads, reducing how much magnesium chloride the department’s trucks spread, Wadleigh explained. But magnesium chloride works only when temperatures stay far below freezing. In a warmer winter, it turns slick, reproducing the dangers of the ice it is supposed to limit. Over time, Wadleigh said, the department will update all its vehicles with new technology that distributes salt more efficiently.

On average, over the last two winters, Claremont spent $168,426 to buy 2,700 tons of salt. This year, salt prices are up, but the city needs much less than it used to.

Who’s responsible for slip & falls on condo ice? - Lexology

A recent slip and fall case shed some light on the risks and pitfalls associated with improperly cleared snow in condo settings. Ultimately, the question in this case turned on the delay in applying road salt in the parking lot. Time to review your snow removal contracts.

Facts

In the midst of the season’s first snowstorm, a condo owner fell on a slippery area in the roadway outside of this condo, as he was walking to his car on his way to work. With some pain he managed to get up, walk to his vehicle and drove to work. He eventually went to the hospital where he was diagnosed with an ankle fracture. He sued the condo corporation and its snow removal contractor.

The evidence showed that road salt was only applied :

• 7 hours after the snowstorm began;
• about 3.5 hours after the snow contractor arrived on site and
• 1.5 hours after the slip & fall.

The delay in applying the sale was due to the system used by the snow removal contractor. A first crew was in charge of plowing the snow but were not equipped to carry and apply salt. This was done by the boss personally, after the fact, on all 14 locations they covered, using his pick-up truck with a snow plow on the front and a salt spreader on the back.

The question ultimately was whether these delays in applying salt are consistent with a reasonable standard of care required of a commercial snow removal contractor in the circumstances.

When questioned, the snow removal principal indicated that he had learned the business “on the job” from subcontracting snow removal for others. He had never taken any formal training, was dismissive of the existence of any “real science or useful guidelines” surrounding the application of road salt as part of winter road maintenance and was instead of the view that these matter are better addressed by “experience, common sense, hard work and rapid on the ground decision making as the weather situation unfolded”. He rejected the suggestion that pre-salting surfaces was useful as you ended up plowing away that salt with the snow.

The law

In this case, the condo corporation had entirely delegated to the snow contractor the winter maintenance obligations and responsibilities. The snow contractor received virtually no direction from condo management and he therefore exercised his own judgement in carrying out his role. He ultimately was the one deciding when he needed to attend the property and how to manage snow removal and ice conditions.

As a result of this, the snow removal contractor (and not the condo) was deemed to be the occupier of the common element property under the Occupiers Liability Act.

Under this legislation:

• an occupier is the “person who has responsibility for and control over the condition of premises or the activities there carried on”;

• The occupier is responsible to take reasonable steps to ensure the reasonable safety of those on the premises.

Question before the judge

The central issue in this case is whether the contractor applied road salt to the driveway and parking areas in a sufficiently timely way to avoid or mitigate the formation of icy conditions that would put the residents at risk of injury through slipping and falling.

The science of snow removal

An expert testified on the science behind snow removal:

• Plowing snow with heavy equipment compresses a thin layer of snow and creates a slippery film on the road – especially when you go back and forth with front loaders, for example;

• Pre-salting is a proactive approach involving applying the salt before the storm arrives to prevent a bond from forming between the pavement and the snow and ice when the storm starts. Alternatively, salt application is required concurrently or immediately after the snow is removed;

• Salt/grit should be applied immediately after the initial snow removal activities. A good way of doing this is to have a salt spreader on the rear of the vehicle as the plowing is done or at least spread the salt immediately after the snow is cleared, before the ice/pavement bond sets in.

Decision

The court concluded that the snow contractor had not met the required standard of care:

[42] The delay in applying road salt was due to an inherent problem in the contractor’s system, which involved Mr. Mitchell personally handling the salt application from his vehicle once he was able to arrive on site. He had to deal with some 14 properties spread around the city, which made a timely application of road salt to be hit and miss, at best. His failure to delegate salting to his plow operators was problematic as was his taking on a large number of client properties resulted in his operation being very overstretched when road salt applications were needed.

Lessons learned

There are a couple of lessons here. You may want to make sure that :

• You retain a professional, well established and experienced snow contractor (and one properly insured);

• They have the resources and capacity to handle the number of properties they have taken on (this one appeared to have been stretched thin with the 14 properties they were looking after);

• They attend your property early enough (in this case, they arrived on site at 7:30; 3 hours after the snow storm started and well within traffic hours);

• Their snow removal protocol meets industry standards (in this case, having the salting done after the fact by a single truck was not adequate);

• Your snow contract properly contains adequate indemnification provisions;

• Someone keeps an eye on your sidewalks, driveways, parking and make sure to have accessible salt bins on location.

You can read the decision here,

Road salt runoff is making freshwater lakes inhospitable | Salon.com

As yet another winter storm descends on the United States, local governments prepare to dig their citizens out by applying de-icing salts to asphalt and sidewalks. Yet the resulting salt pollution in freshwater ecosystems may prove to be a far more difficult hole to dig ourselves out of, as de-icing chemicals have become the status quo for creating upwards of an 80% reduction in rates of traffic accidents.

For those of us living in colder climates, we begrudgingly accept certain oddities of winter — the rasp of snow plows in the early hours of the morning and a thick layer of brine over everything — for the sake of safer roads. Some municipalities such as those in New York state apply an average of 23 tons of salt every mile for each lane of traffic. While we rarely question the wisdom of such precautions, consequences linger out of sight as de-icing salts seep into aquifers and wash into waterways.

Along with agriculture fertilizers, mining operations, and climate change, de-icing salts contribute to a growing salinity problem in freshwater lakes. New research published in the Proceedings of the National Academy of Sciences determined that government regulations that set thresholds on ionized chloride from human pollutants fail to sufficiently protect critical freshwater zooplankton species. In the absence of these microscopic grazing organisms, algae proliferate and starve the whole ecosystem of oxygen, and the whole food chain falls apart.

"It's becoming increasingly clear that we need to develop new chloride thresholds, new water quality guidelines that really do protect our freshwater ecosystems from changes due to elevated salinity," Dr. Bill Hintz asserted.

Hintz emphasized the urgency for governments to reassess thresholds for what are considered permissible concentrations of chloride in freshwater lakes.

"The desalination process is really expensive," he added. "We can't do it on a massive scale, so once we pollute a lake ecosystem with salt, that salt will stay in concentration pretty much until the lake turns over."

Dr. Hintz and other scientists from The University of Toledo collaborated with Queen's University in Kingston, Ontario to lead an international study to determine the impacts of salinity on zooplankton across North America and Europe. Previous research has focused on lab settings, but this study is unique both in its approach and scope. From 16 different sites the team extracted what Dr. Hintz called semi-natural communities of zooplankton. Their goal was to assess thresholds for chloride ions in relation to variability in the specific geology, water chemistry, land-use, and species composition of the sites.

Generally, scientists observed massive reductions of all major zooplankton groups when exposed salinity levels deemed safe by water quality guidelines in the United States, Canada and throughout Europe.

"We're seeing such a decline in the abundance of the zooplankton community that these guidelines really aren't protective of these communities," Dr. Hintz suggested. "When you lose those zooplankton — those zooplankton eat a ton of algae — at 47% of the sites, we see a greater algal abundance, which would be suppressed if we had the zooplankton feeding on that algae."

Zooplankton are a critical food for young fish and smaller species. Though it remains to be seen, fish populations are likely to shrink as multiple trophic levels of the food chain constrict. This is what biologists refer to as the cascade effect, a chain reaction caused by the disruption of one trophic level of the food chain.

In reality, the impact is more like a ripple than a cascade though. The impact does not just affect one linear chain. While high salinity does not necessarily create "harmful algal blooms" that are toxic, a reduction of zooplankton undoubtedly could cause an overabundance of algae and other phytoplankton, sometimes going so far to create inhospitable "dead zones" that lack oxygen and light. 

"I would say this issue is like climate change," he insisted. "We need to act now. When you act 10 years, 15, 20, 30, 50 years down the road, every year that passes by, if you're still using the salts you're still increasing the concentration. Then who knows how long it will take to go away. The science is becoming clear though. We need to do something about salt pollution."

Government guidelines insufficient to protect freshwater ecosystem from salt pollution (phys.org)

Current water quality guidelines aren't protecting freshwater ecosystems from increasing salt pollution due to road de-icing salts, agriculture fertilizers, and mining operations, according to an international study that included researchers at Rensselaer Polytechnic Institute. Published today in the Proceedings of the National Academy of Sciences (PNAS), the research shows that freshwater salinization triggers a massive loss of zooplankton and an increase in algae—even when levels are within the lowest thresholds established in Canada, the U.S., and throughout Europe.

"It's clear that salt pollution in freshwater lakes, streams, and wetlands, even when constrained to levels specifically chosen to protect the environment, threatens the biodiversity and overall function of freshwater ecosystems. This is a global problem that has the potential to impact ecosystems and human health," said study co-author Rick Relyea, an expert in the impacts of road salt on freshwater ecosystems, and director of Rensselaer's Darrin Fresh Water Institute. "The good news, as we've seen in our own region, is that communities are learning how to apply road salts in smarter ways while still providing safe roads and saving considerable money in snow and ice removal."

Dr. Relyea, a member of the Rensselaer Center for Biotechnology and Interdisciplinary Studies and director of the Jefferson Project at Lake George, has conducted extensive research on the impacts of road salt on aquatic environments. His work has helped to establish that road salt masculinizes developing frogs and obliterates circadian rhythm in zooplankton. In recent work, Dr. Relyea has collaborated with an experimental network of 16 sites in four countries across North America and Europe. Earlier this year, Dr. Relyea and that network produced experimental findings led by Canadian scientist Marie-Pier Hébert, which show that lake salinization reduces zooplankton abundance and diversity.

The PNAS research, led by The University of Toledo and Queen's University in Kingston, shows that even at salt concentrations below ranges government regulators have deemed safe and protective of freshwater organisms, significant damage is being done to freshwater lakes.

In particular, increasing salt levels threaten zooplankton, a critical food resource for many young fish, and changes caused by rising salinity could alter nutrient cycling, water quality and clarity, and instigate growth and population declines in economically important fish species.

Researchers say the results indicate a major threat to the biodiversity and functioning of freshwater ecosystems and the urgency for governments to reassess current threshold concentrations to protect lakes from salinization sparked by sodium chloride, one of the most common salt types leading to the salinization of freshwater lakes.

"Salt pollution occurring from human activities such as the use of road de-icing salts is increasing the salinity of freshwater ecosystems to the point that the guidelines designed to protect fresh waters aren't doing their job," said Bill Hintz, assistant professor of ecology at The University of Toledo, author, and co-leader of the project. "Our study shows the ecological costs of salinization and illustrates the immediate need to reassess and reduce existing chloride thresholds and to set sound guidelines in countries where they do not exist to protect lakes from salt pollution."

The lowest threshold for chloride concentration in the U.S. established by the Environmental Protection Agency is 230 milligrams of chloride per liter. In Canada, it's 120 milligrams of chloride per liter. Throughout Europe, thresholds are generally higher.

It can take less than a teaspoon of salt to pollute five gallons of water to the point that is harmful for many aquatic organisms.

In other countries such as Germany, chloride concentrations between 50 and 200 milligrams per liter are classified as "slightly polluted by salts," and concentrations between 200 and 400 milligrams per liter are classified as "moderately polluted by salts." The drinking water guideline is 250 milligrams per liter across much of Europe.

But as the study shows, negative impacts occur well below those limits. At nearly three quarters of the study sites, chloride concentration thresholds that caused a more than 50% reduction in zooplankton were at or below the governments' established chloride thresholds.

The loss of zooplankton triggered a cascading effect causing an increase in phytoplankton biomass, or microscopic freshwater algae, at almost half of the study sites.

"More algae in the water could lead to a reduction in water clarity, which could affect organisms living on the bottom of lakes as well," said Shelley Arnott, professor of aquatic ecology at Queen's University and co-leader of the project and paper. "The loss of zooplankton leading to more algae has the potential to alter lake ecosystems in ways that might change the services lakes provide, namely recreational opportunities, drinking water quality, and fisheries."

The scientists chose to study zooplankton communities from natural habitats instead of short-duration, single-species laboratory studies because such an approach encompasses a greater diversity of species and naturally occurring predator-prey and competitive interactions over a six-to-seven-week timespan within the zooplankton community.

The study was designed to better understand how the chloride thresholds would hold up in a more natural ecological setting.

They focused on determining if current chloride-based water-quality guidelines protect lake organisms in regions with different geology, water chemistry, land-use, and species pools.

"Many salt-contaminated lakes with chloride concentrations near or above thresholds established throughout North America and Europe might have already experienced food web shifts," Dr. Hintz said. "This applies to lakes across the globe, not only among the study sites. And the variability in our experimental results demonstrate how new thresholds should integrate the susceptibility of ecological communities at the local and regional scale. While the government guidelines may protect freshwater organisms in some regions, that's not the case for many regions in the U.S., Canada, and Europe."

Solutions also include finding ways to strike a careful balance between human use of salt responsible for freshwater salinization with ecological impacts, such as reducing the amount of road salt used to melt winter snow and ice to keep people safe and traffic moving. A previous study led by Dr. Hintz suggests best management practices.

Scientists across the globe contributed to the research "Current water quality guidelines across North America and Europe do not protect lakes from salinization."

A salty balance: Road safety vs the environment | The Star

One of the most harmful things about winter is the white stuff that covers our roads and sidewalks. We’re not talking about snow, but rather the road salt that is used whenever snow falls on our roads.

Each year the City of Toronto lays down up to 150,000 tonnes of salt on its approximately 5,100 kilometres of roads. It’s used to control snow and ice so that driving, walking and getting around in general can be safer.

Salt is popular with municipalities and contractors because it’s cheap and easy to distribute. But, where road salt is concerned, there is plenty to worry about. One problem is that it doesn’t always work. Salt is used to lower the freezing point of water to make it harder for ice to form, but it only works when temperatures are above -7 C. When temperatures fall below that, the city applies brine – a salt and water mixture – ahead of the snowfall, in order to restrict the ability of water and snow on roads to freeze.

Road salt is also harmful to the environment. In 2001, Environment Canada published the results of a five-year assessment on the impacts of road salts, noting it had an adverse effect on freshwater ecosystems, soil, vegetation and wildlife. In March 2021, the University of Toronto published the results of a study that looked at the impact of road salt on aquatic habitat in the city’s rivers. It found that salt run-off in the spring was causing negative impacts well into the summer.

“Of the samples we took from four GTA rivers and creeks during the summer, we found that nearly 90 per cent exceeded federal guidelines for long-term exposure of aquatic life to chloride,” said Donald Jackson, a professor of aquatic ecology in the department of ecology and evolutionary biology.

Similar findings across the southern Great Lakes have been found by WWF Canada. Its studies have revealed that many urban and rural waterways in southern Ontario are showing record high chloride levels. Some are even as salty as the ocean in the winter, according to WWF’s data.

“Ontario is over-salting its parking lots, sidewalks and roadways,” said Elizabeth Hendriks, vice-president of freshwater with WWF Canada. “A small pill bottle or saltshaker is all that’s needed to melt the equivalent of a city sidewalk slab.”

Beyond environmental issues, road salt is corrosive and can damage vehicles, stains shoes and clothing, and can damage lawns during the spring melt.

The drawbacks of road salt are compelling municipalities and contractors to find ways to minimize its use. Some municipalities are also experimenting with alternative products to see if salt can be replaced altogether. In 2016, the City of Toronto produced a Salt Management Plan, which included a list of ways the use of salt can be reduced. Examples include improved training of operators and fitting more trucks with anti-icing and pre-wetting equipment.

In an email, Hakeem Muhammad, transportation spokesperson for the city, said road salt continues to be the best and most effective way to keep roads safe in winter weather. However, the city is aware its use is associated with negative environment impacts. City staff work to reduce those impacts as much as possible by actively managing salt use, Muhammad said, adding it aims for a 10 to 15 per cent reduction by pre-wetting the salt so less is required.

“Salt spreaders are calibrated at the beginning of each winter season and operators are being continuously trained,” Muhammad said. “New equipment will be purchased as part of the new winter services contracts starting in the fall of 2022, which will be more efficient in their salt usage.”

For private contractors, best practices for salt management can be learned through Smart About Salt, a not-for-profit agency. Its online training and certification programs provide advice on how to minimize the use of salt to save money and help the environment at the same time.

Alternatives to road salt exist and continue to be explored. The Sustainable Technologies Evaluation Program – a collaboration between the Credit Valley, Lake Simcoe region and Toronto region conservation authorities — has conducted research on various alternatives. These can be broken down into three categories: chloride de-icers, acetate de-icers, and agricultural byproducts (organics). The research concluded that all the alternatives have drawbacks, including higher prices, specific application requirements, lack of effectiveness and associated environmental issues.

A 2014 study by the University of Waterloo, in partnership with the Toronto and Region Conservation Authority, looked at organic and semi-organic alternatives. The study determined that organic anti-icers had lower chloride and sodium levels, but contained higher levels of nutrients and organic carbon. When temperatures drop below -20 C, Toronto spreaders use a de-icer made from a mixture of sugar beet molasses and (much less) salt. In Wisconsin, the salty brine from making mozzarella cheese has been used for several years and has had positive effects.

Another alternative are traction agents. Sand is often used this way in rural areas where salt isn’t effective. There are also organic traction agents, such as EcoTraction, a product derived from volcanic rock. It can be used on its own by homeowners or mixed in with de-icers and spread on roads or parking lots by municipalities and contractors.