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Too Much Salt: Good for Winter Travel, but with Consequences for Environmental and Human Health | Mirage News

An overuse of road salt in the winter has potentially harmful effects for everything from wildlife to groundwater

The winter months can bring dicey travel conditions, but those can be made safer with shovels, plows, and deicers like road salts. For road salts, a little can go a long way in improving safety, but its use is not without consequences. Researchers from the College of Agriculture, Health and Natural Resources and the College of Liberal Arts and Sciences are working to better understand the numerous environmental impacts of using too much salt on roads and walkways.

Bigger Frogs, More Mosquitos

Department of Natural Resources and the Environment researcher Tracy Rittenhouse and her group are investigating the effects road salts on amphibians.

“Previous research showed that tadpoles tend to metamorph larger in size from salty wetlands and high salinity conditions,” Rittenhouse says. “Generally, we think larger size as a good thing but we’re not sure why they’re larger or how they might be different physiologically.”

Rittenhouse explains that frogs starting life in saltier conditions, though larger, don’t seem to have any advantages later in life, whereas frogs from lower salt conditions started life smaller but grew much faster and larger over time. These results show that not only are amphibians amazingly tolerant to salt, but that we have much to learn. Despite the quantities of salt entering wetland environments, this resilience is why we have not seen massive declines in amphibian populations, says Rittenhouse.

Another experiment completed by an undergraduate student in her lab group showed that juvenile frogs not only detect if soil is salty, they will consistently avoid those conditions.

“That project opened up this whole arena of what we really should be looking at is the juvenile and adult frogs and how they might be responding to salinity in the terrestrial environment,” she says.

Rittenhouse says there are other consequences to heavily salting the road, including disruptions in the food web that can harm some members of the ecosystem while benefiting others.

“For example, salt generally kills most of the zooplankton,” Rittenhouse says. “Zooplankton eat phytoplankton, and tadpoles eat phytoplankton, so with fewer zooplankton, the tadpoles have more food, because those competitors are gone. You get shifts in the communities, but it’s not all negative for everything. Another thing that tends to do well in high salinity wetlands is mosquito larvae. Although a lot of other things die in high salinity conditions, the mosquitoes can tolerate it fairly well too. Maybe that would be a motivator to use less salt.”

Rittenhouse cautions that unless the “more salt is better” mindset changes, we will start to see more negative effects.

Future Changes in Plant Communities?

UConn researchers Beth Lawrence, Ashley Helton, and Gary Robbins recently published a study in Ecosphere investigating the potential impacts of road salts on plant communities and biogeochemistry in wetlands. The road-dense and wetland-abundant landscape of the Northeast provides a perfect setting for this type of investigation, says Lawrence.

“Other studies have found higher invasive species abundance and shifts towards salt tolerant species,” she says. “Surprisingly, we did not see strong shifts in the vegetation even where we observe elevated salinity in the roadside. We saw that invasive species might have a competitive advantage near the road edge and we’re unsure if that was road salt-induced.”

To get a better idea of potential salinity thresholds, the researchers looked at the seed bank — dormant seeds in the soil waiting for optimal germination conditions. They collected soil from a nearby forested wetland and exposed the banked seeds to different salinities to study seedling emergence under varying conditions.

“We found increased salinity reduces numbers of seeds germinating, the seeding density coming out of the soil was lower, and the diversity of species coming up was reduced,” Lawrence says, “suggesting that there might be some plants that are more tolerant and more capable of germinating under higher salinity conditions.”

Fortunately, Lawrence says these experimental salinity levels are higher than field conditions which are currently not salty enough to elicit a strong response.

“If high rates of road salt continue to be applied, we certainly could surpass that threshold and see strong changes in the vegetation in the future.”

A Sodium-lowering Solution

Mike Dietz, an Extension educator and faculty member in the Department of Natural Resources and the Environment, is working to address high salt application rates. His research also monitors salinity levels around UConn Storrs, and he says the best time to revise application rates is now.

“From some of the monitoring that we have here on campus with Eagle Brook, once we implemented Green Snow Pro training, given by UConn’s T2 Center, application rates were greatly reduced, over the course of two years, we started to see salt concentrations in the stream come down,” Dietz says. “In Connecticut we have this ‘glacial till’ soil that the water moves through very slowly. For example, for water to travel from Storrs Hall to Swan Lake, it takes around 10 months, so it really is a delayed response as we reduce the application rates. It is going to be a year to two years before we see a drop.”

Major hurdles include social factors and expectations, which Dietz says is a largely un-examined issue.

“It’s a big issue. In the 1980s and 1990s, we saw a steep increase in road salt application rates. I think that is when expectations started to change. Whereas previously people would just stay at home after a winter storm, now everybody’s got to get out and get to work. There’s a lot to be considered there,” he says.

Dietz says this issue is getting the attention of state legislators after a road salt bill was proposed in 2021. Dietz and a state-wide chloride workgroup is now working with legislators to craft the best bill possible for the upcoming session. The bill would require private contractors to take the Green Snow Pro training, which Dietz says would be a step in the right direction.

“In New Hampshire about 50% of the salt load that goes down is on private properties,” he says. “Having the liability relief for contractors and property owners that go through this training would be huge, and would really make a difference in the amount of salt that gets applied in Connecticut.”

Robbins, a professor in the Department of Geosciences, agrees that this issue needs to be addressed, and says road salt contamination of groundwater is one of the biggest problems stemming from the overuse of road salt.

“We are not slowing down how much salt is applied,” he says. “The salt gets into the groundwater where elevated concentrations persist even in the summer. It could take a very, very long time for that salt to get out. We have done a lot of groundwater monitoring for salt over the years, and found that the salt concentration has been increasing, on average over ten times natural levels.”

Everyone can do their part to reduce salt use at home, as there are alternatives to dumping salt, says Dietz. Plowing or shoveling driveways and sidewalks will allow the sun to heat the surfaces and melt the snow and ice. It’s also important to ensure the meltwater can drain away, so it doesn’t later re-freeze on the surface. Dietz has had luck with this method, and says he doesn’t need to use any salt at his own home. If you do use salt, just make sure you don’t overdo it, he says.

Road salt threatens Michigan lakes and rivers. Can an alternative take hold? (michiganradio.org)

Road salt is threatening the Great Lakes’ famous fresh waters and creating even bigger problems for the inland rivers, lakes and aquifers – not to mention your car’s undercarriage.

But decades of experiments with other options, from beet- and corn-based deicers to sand and chemical mixes, have yet to yield an alternative that’s anywhere near as effective and affordable.

“It’s far cheaper than anything else out there, and it works far better,” said Craig Bryson, spokesperson for the Road Commission for Oakland County, which maintains Michigan’s largest county road system.

As much as his agency cares about the environmental impacts of road salt, slippery roads are a major winter crash hazard, and “human life has to be the single highest priority in our decision matrix.”

Scientists and lawmakers have long worried about the environmental costs of the rock salt mined from underground caverns (like this one in Detroit) and then spread over roadways to keep snow and ice at bay.

Just one measure: Last month, scientists at the University of Wisconsin-Madison and Michigan State University released results of a study revealing that society’s reliance on rock salt is salinating Lake Michigan.

As Michigan endures another icy winter, state and local road officials say the most realistic remedy to Michigan’s salt pollution problem is simply using less. And a pilot program to replace solid rock salt with a liquid salt brine is helping them do just that.

Turning rivers saline

In Lake Michigan, the Wisconsin and MSU researchers found, concentrations of chloride (an element in salt) have increased dramatically since the 1800s, from 1-2 milligrams per liter of water to 15.

And salt concentrations are creeping upward by another milligram every couple of years, thanks to million metric tons of chloride that make their way into the lake after dissolved salt seeps into the region’s rivers.

That’s still well below the hundreds of milligrams known to sully drinking water supplies and imperil freshwater species. But even small increases can trigger unknown ecosystem changes and secondary effects such as drinking water pipe corrosion, said Hilary Dugan, an associate professor at the University of Wisconsin-Madison’s Center for Limnology and lead author of the study.

Lake Michigan is still “extremely fresh” water, Dugan said. “There’s no cause for alarm. But I think people should be aware that it is rising and that is fully because of human-derived salts.”

More immediately dire are the dramatic impacts salt can have on inland lakes and streams, particularly those near roads that are heavily salted throughout the winter and early spring.

Some rivers get such intense salt shocks, Dugan said their salinity can mimic ocean water at times. The sudden change can release heavy metals from the riverbed and harm fish and wildlife.

Salt has so altered the chemistry of some inland lakes, their water has ceased to mix. Instead, the dense salt-laden water settles to the bottom, creating oxygen-scarce dead zones. Many North American lakes are in danger of becoming so salty over the next 50 years, they’ll surpass federal chloride standards.

Road salt can also taint groundwater, forcing residents to dig new wells, and damage crops.

“When you put salt on your driveway or sidewalk, in the springtime, you might notice dead grass on the side,” said Mark Geib, administrator for the Michigan Department of Transportation’s Transportation Systems Management and Operations Division. “That’s because it kills the grass.”

Beets are a bust. But what about brine? 

For now, many road crews are focused on using less salt, rather than using some other substance.

In Oakland County, Bryson said supplementing solid rock salt with a liquid salt brine has helped the agency reduce its annual salt usage from about 85,000 tons a year in the early 2000s to 63,000 tons today.

Technological improvements have helped too, he said, including computerized systems that ration salt to prevent overspreading. And simply training drivers to resist “cranking it up full-bore” has made a difference in the department’s salt use, he said.

The naturally-occurring brine is also cheap, he said, costing the county only the price of electricity to pump it to the surface.

The Michigan Department of Transportation is also experimenting with a brine made by mixing rock salt with water to create a 23% salt solution, Geib said. A pilot project last year in Montcalm County cut down on salt costs by about 20%, Geib said, and worked so well it’s now being expanded to Grand Ledge and Mt. Pleasant.

For a state agency that spends between $25 million and $30 million to purchase 450,000 tons of salt annually, using less is a cost-cutting measure as much as an environmental move. Experiments in other states have helped road crews use up to 40% less salt.

And what’s good for the agency’s pocketbook also does less damage to the environment: A 2019 study in the journal Environmental Science & Technology showed that using brine decreased chloride runoff into streams by 45%.

Within 10 years, Geib predicted, MDOT could be using brine instead of salt on most Michigan highways.

There are other effective alternatives out there. But they can be orders of magnitude more expensive than salt. The calcium magnesium acetate that’s used on the Zilwaukee Bridge to prevent corrosion on the bridge, for example, is 50 times more expensive.

Other options, such as heated roads, show promise but are currently too cost-prohibitive to use on a broad scale. And simply leaving some roads snow-covered, as is the practice in parts of the U.P., wouldn’t fly in more heavily-populated parts of Michigan, said Bryson of Oakland County.

“People expect to be able to get to work in rush hour on days when there's a massive snowstorm, in the same amount of time that they can in the middle of summer,” he said. “And if they can’t, we hear about it.”

Road Salt Works. But It’s Also Bad for the Environment. - The New York Times (nytimes.com)

The chemical is effective at keeping roads free of snow and ice, but it also has damaging consequences, according to a growing body of research.

As snowstorms sweep the East Coast of the United States this week, transportation officials have deployed a go-to solution for keeping winter roads clear: salt.

But while pouring tons of salt on roads makes winter driving safer, it also has damaging environmental and health consequences, according to a growing body of research.

As snow and ice melt on roads, the salt washes into soil, lakes and streams, in some cases contaminating drinking water reservoirs and wells. It has killed or endangered wildlife in freshwater ecosystems, with high chloride levels toxic to fish, bugs and amphibians, according to the Environmental Protection Agency.

“It’s an issue that requires attention now,” said Bill Hintz, an assistant professor in the environmental sciences department at the University of Toledo and the lead author of a recent research review published in the journal Frontiers in Ecology and the Environment.

“There’s plenty of scientific evidence to suggest that freshwater ecosystems are being contaminated by salt from the use of things like road salt beyond the concentration which is safe for freshwater organisms and for human consumption,” Dr. Hintz said.

Road salt is an environmental pollutant.

Salt has been used to de-ice roads in the United States since the 1930s, and its use across the country has tripled in the past 50 years, Dr. Hintz said. More than 20 million metric tons of salt are poured on U.S. roads each winter, according to an estimate by the Cary Institute of Ecosystem Studies in New York, and the environmental costs are growing.

Still, little has been done to address the environmental impact of road salt because it is cheap and effective, said Victoria Kelly, the environmental programming manager at the Cary Institute. By lowering the freezing temperature of water, salt prevents snow from turning to ice and melts ice that is already there.

Road salt is made from sodium chloride, the same chemical found in table salt. Of all salt consumed in the United States, about 43 percent is used for highway de-icing, according to the U.S. Geological Survey in 2020.

The consequences of insufficiently salting roads were seen this week, when hundreds of drivers were stranded by a snowstorm on Interstate 95 in Virginia. Officials said the storm began with rain, which washed away road salt and made it difficult to keep roads clear. More snow fell in the Mid-Atlantic States and the Northeast on Friday.

But environmentalists say the problems associated with road salt are getting harder to ignore. Ms. Kelly said the accumulation of salt in drinking water reservoirs in some places was harming people on low-sodium diets.

A 2018 study of wells in Dutchess County, N.Y., found that sodium concentration in wells reached levels as high as 860 milligrams per liter — much higher than the federal and state recommendation that levels not exceed 20 milligrams per liter for people on very low-sodium diets and 270 milligrams per liter for people on moderately restricted sodium diets.

A separate 2018 study in the journal Environmental Science and Technology showed that 24 percent of private drinking wells in New York were contaminated with salt that had been used on roads. About 15 percent of people in the United States get their water from private ground wells, while the rest rely on community water systems, according to the Centers for Disease Control and Prevention.

More counties and states are rethinking the amount of salt they use because of the associated costs. Last month, Gov. Kathy Hochul of New York announced appointments to the Adirondack Road Salt Reduction Task Force, established to review road-salt contamination.

“I have no doubt that this group of individuals will work tirelessly to protect our state from the adverse effects of road salt,” Ms. Hochul said. “We look forward to seeing this group finally convene and make progress in preventing further pollution to our waterways and our environment.”

There are consequences for wildlife, too. Dr. Hintz said his review showed that elevated salinity levels in freshwater ecosystems had already caused a reduction in the abundance and growth of freshwater organisms and a reduction in their reproduction outputs.

Road salt also corrodes vehicles and bridges, causing $5 billion in annual repairs in the United States, according to an estimate by the Environmental Protection Agency. AAA suggests drivers wash and clean their vehicles regularly during winter to help offset the effects of road salt and to limit driving when salt and other de-icing chemicals are at their highest concentrations.

In Britain, the Salt Association said that salt was the cheapest form of de-icing material and that it had a low environmental impact when used responsibly. “As with all highway maintenance activities, there are environmental implications from winter road maintenance,” the organization said in a statement. “Highways depots, spreading vehicles and the de-icing agent all contribute, but with good management, this burden can be minimized.”

Alternative methods can mitigate the damage.

While there is not a perfect solution to the issue, there are alternatives that can significantly reduce salt usage without compromising driver safety.

One method involves treating roads before storms with a salt brine solution, which can lead to a 75 percent reduction in the amount of salt used while keeping roads just as safe, according to the Cary Institute. Building better salt storage sites can also minimize waste.

Some counties, like Jefferson County, Wis., have already made changes. Bill Kern, the county’s highway commissioner, said switching to a brine solution had enabled the county to cut its salt use by up to 60 percent since 2018 without an increase in the number of accidents. By using less salt, the county has reduced its overall cost for winter maintenance of state and county highways by 20 percent since 2018, saving about $1.6 million, Mr. Kern said.

Over the past decade, some states, including Rhode Island, have passed legislation aimed to reduce their use of road salt and have increasingly applied a brine solution to roads in winter, but environmentalists say more needs to be done.

While engineers have developed better alternatives, they have not been widely implemented in part because they require upfront costs for purchasing equipment, Ms. Kelly said.

“It’ll save us money, and it’ll help to save our freshwater,” she said, while adding that “because of that legacy effect, it’s going to take a really long time to see the impact of the steps we take.”

Ice melting salt is a hot commodity in Prince Rupert | The Star

Safety salt is a hot commodity in Prince Rupert and residents may find it difficult to locate a bag from suppliers in the city during the ongoing cold snap.

As of Jan. 5, multiple retailers across town have run out of the ice melting product and some with remaining supplies have limited customers to buying one bag of salt per person.

“It’s become frustrating for everybody,” Maria Melo, manager at Prince Rupert Home Hardware Building Centre, said.

The problem seems to be a lack of supply that is being compounded by Prince Rupert’s remote location away from stock, Melo said, adding other winter supplies such as shovels are in good supply, and it is only melting salts they have run out of.

Orders kind of go by pecking order, due to location, she said. At the end of the day, somebody closer to the warehouse is probably going to get salt before us due to different load-up and delivery dates.

“So, someone closer might get it before us by the time they hit my order,” she said.

To be equitable to all customers, Melo placed a limit on customers to one bag each before supplies ran out.

“It wouldn’t be fair to sell somebody a whole skid and then have the rest of my customers struggling,” she said. “… but most customers are understanding because this is not normal weather for us. It’s a long stretch of super cold and snow.”

Though Melo has a lot of melting salt on backorder, the product will only be shipped once supplies are available. More salt should arrive by Jan. 10, she said.

Windsor Salt Ltd., which manufactures the recognizable large 10-kilogram yellow bags of salt is located in Ontario and ships salt to B.C. The Northern View has reached out to the company for comment.

While residents may be scrambling to snag a bag of salt, the City of Prince Rupert operations team is not experiencing salt supply issues at the moment, Veronika Stewart, communications manager, wrote in an email, so road maintenance can be kept up.

The Northern View reached out to some retailers in Prince Rupert to confirm the shortage of salt.

With files from K-J Millar

The Environmental Impact of Road Salt and Sustainable Alternatives (greenmatters.com)

Road salt: although it closely resembles the minerals we use to flavor our food, it couldn't be more different. Road salt is used to maintain the roads in the winter, preventing cars from slipping on snow and ice. It's composed of chloride salts of sodium, potassium, magnesium, and calcium. And although it sounds like a natural solution to inclement weather, the environmental impact of road salt is evidently quite high.

"Consider how easily salt can corrode your car," Joseph Stonberg wrote in Smithsonian Magazine. "Unsurprisingly, it's also a problem for the surrounding environment — so much that in 2004, Canada categorized road salt as a toxin and placed new guidelines on its use."

"And as more and more of the U.S. becomes urbanized and suburbanized, and as a greater number of roads criss-cross the landscape, the mounting piles of salt we dump on them may be getting to be a bigger problem than ever."

How does road salt impact the environment?

Many communities, especially those that receive notable amounts of snow, need road salt in order to survive the winter. Road salt works by combining with water and creating a solution that doesn't freeze, according to Save The Water. It's then scattered along the road each winter, to prevent black ice from forming, which can cause serious, potentially fatal road accidents. Within 25 minutes of being applied, road salt can reduce accidents by up to 85 percent.

But there are many ecological drawbacks to using road salt. As per the EPA, road salt can contaminate waterways by infiltrating nearby waters such as reservoirs and wells. High levels of salt in drinking water can not only affect people with certain health conditions, but it can also kill fish, bugs, and other wildlife.

“Salt is something of a ticking time bomb for freshwater,” Riverkeeper President and Earth Institute adjunct professor Paul Gallay stated in a Columbia University report.

“Studies suggest that the increasing concentrations we see in many places may be the result of road salt spread decades ago, which reached groundwater, and is only now slowly reaching surface waters,” he continued.

Road salt can also increase soil erosion, which can kill plants and trees. It also damages roadways, buildings, and cars — according to Columbia University, it may cause up to $5 billion in damages in the U.S. per year. Needless to say, it's truly wreaking havoc on our communities and ecosystems.

Here are eco-safe alternatives to road salt:

Recently, EcoWatch reported on sustainable road salt alternatives, which could seriously help out communities this winter. In addition to sustainable de-icers, the publication suggests turning to things like alfalfa meal, coffee grounds, sugar beet juice, and grape skin compounds, which all effectively melt ice. Brines, such as pickle juice, can also do the trick.

Combining those ingredients with increased snow removal (by shoveling, applying heat, or using a snow blower) can definitely lower your chances of a slippery road or driveway. But it's important to transition to these alternatives to lower our impact on a larger scale.

As icy conditions return, City of Ottawa must avoid using too much road salt, environmental advocates insist - Capital Current

Heavy snowfall, freezing rain, and below-zero temperatures have returned for the winter season, and so has the use of road salt on every street, sidewalk, and pathway. But as icy conditions ramp up, environmental advocates are keeping a close eye on how much road salt the City of Ottawa is using.

According to Christopher Paquette, the city’s program manager for operational research and projects, Ottawa uses about 185,000 metric tons of salt each year.

“In order to ensure public safety, the City of Ottawa has a requirement to maintain roads during the winter to a prescribed standard based on provincial regulations,” Paquette stated in an email statement. “A de-icer is required to maintain roads to a bare condition, and the industry’s primary de-icing method is road salt.”

Matt Fyfe, a scientist with the local environmental organization Ottawa Riverkeeper, describes road salts as a category of mineral — typically sodium chloride — used as a de-icing agent on road and walking paths during the winter.

But while sodium chloride is essential for improving winter road safety, it can also have detrimental impacts on aquatic wildlife.

“When water melts, it enters stormwater drains or it can go right into creeks and ditches, and those are habitat for aquatic organisms, micro invertebrates and macro invertebrates, and fish and even some plant species,” Fyfe said. “And all of these groups of organisms have different sensitivities to chloride, which can be toxic at different concentrations.”

In 2019, Ottawa Riverkeeper began monitoring the levels of sodium chloride in urban streams, creeks, and rivers around the city. Fyfe said the results have shown that Ottawa’s water sources can sometimes reach sodium chloride levels as high as those in oceans. This will be the third year of the monitoring project, and the organization’s volunteers will be keeping an eye on 14 testing sites around the city.

“Over the course of the winter, almost half of our sites regularly exceed the toxicity threshold,” Fyfe said. “There are some sites in particular, where it’s especially bad. Those are sort of close to big infrastructure projects or next to highways. But even in residential areas, there’s a lot of salt that’s getting into the streams.”

Salt levels in urban water sources can sometimes be high enough so consistently that the issue is considered chronic, according to Kelsey Scarfone, the policy and campaign manager for conservation at Nature Canada.

“It’s a very unnatural disturbance that we’re introducing into their habitats,” she said. “It’s causing real problems, especially in the lower levels of the food chain. There’s a lot of really small creatures that are quite sensitive to the salinity of their waters. And, of course, these creatures are adapted to freshwater habitats that they signed up for.”

The problem, Scarfone said, is that there have so far been no alternatives that can produce the same de-icing effect that makes road salt an essential winter safety tool. While popular products like sand and gravel increase friction, only road salt has been able to break through stubborn ice cover.

But that doesn’t mean the negative environmental impacts are inevitable.

“The problem is that we’re using way too much (road salt),” Scarfone said.

While cities might be worried about liability from slips and falls on their properties, Scarfone argues that reducing salt use “should be a priority” for municipalities, not only because of the environmental impacts, but because of the cost.

“It’s wreaking havoc in a lot of ways,” she said. “They’re destroying not just shoes, but also infrastructure. It can be quite hard on all of our expensive infrastructure and also on our cars.”

Scarfone also said that while doing away with road salt entirely probably isn’t an option right now, projects such as Ryerson University’s road salt reduction pilot have seen promising early success.

In his statement, Paquette said that the city has taken several measures over the years to reduce its road salt use, including developing a detailed salt management plan, and investing in computer controllers for salting trucks to more accurately control the amount of salt spread on roads.

He added that the city reports its salt usage to the Ministry of Environment annually, and that the municipality intends to review its Salt Management Plan for the third time in the first quarter of 2022.

“The city is proud to be a leader in salt management,” said Paquette, “and is constantly looking at new products and technologies to increase productivity and minimize the environmental impact of our operations.”

Winter road salting has year-round consequences (theconversation.com)

Every fall, Canadians patiently wait for the turning of the trees and the crunch of leaves. In winter, we hear a different sort of crunch — the crunch of road salts.

Road salts are used to remove ice from surfaces like roads, sidewalks and parking lots. When people talk about road salts, they are often concerned with what salt may be doing to their vehicles, dog’s paws or winter boots.

There are also some environmental concerns, as road salt ultimately makes its way into our soils, local lakes and rivers. Salty water flows into our soils and local water bodies through surface runoff and stormwater pipes, and eventually makes its way into groundwater. This furthers the long-term storage of salt in the environment and further impacts freshwater aquatic life, government infrastructure and drinking water.

These concerns are usually voiced during the winter, when we actively see salt trucks and piles of salt on our drives or walks to work and school. While some of our worries disappear as the warm spring weather comes, my research shows the effects of extensive road salting on the environment last year round.

My research with Donald Jackson at the University of Toronto showed elevated chloride concentrations — which are highly correlated with road salt — can now be found throughout the year in freshwater systems in the Greater Toronto Area. The impacts of road salt are not commonly studied in the summertime. However, understanding how it may be impacting the environment in the salt “low season” is important for understanding the gravity of the situation.

Our study found that during the summertime, which is also the low season for chloride, chloride concentrations exceeded established Canadian federal guidelines for protection of aquatic life.

At some of the sites monitored, we found that over 50 per cent of the aquatic biological communities can be considered to be stressed by chloride based on these guidelines, which were based on toxicity tests to aquatic organisms.

This means that summertime is now a time of likely chloride stress, higher water temperatures and early life stages of aquatic organisms (like eggs and larvae) which may be more sensitive to stress. These factors combined put aquatic species at elevated risk.

Why should we be concerned?

Road salt poses a risk for freshwater aquatic species, which rely on low salt levels. Freshwater species have specific biological adaptations to low salt levels, unlike their ocean counterparts which have different types of adaptations.

Studies show that increased chloride concentrations, associated with salt, can lead to disruptions in food webs, as sensitive species are stressed at high concentrations. For an aquatic organism, salt stress can lead to the diversion of energy to maintain basic functioning, which means less energy is directed to growth and reproduction.

High salt concentrations have been found to lead to decreases in egg mass for aquatic organisms, and decreases in growth rate. This essentially means sensitive species may eventually be “filtered out” of food webs, leading to declines in biodiversity.

Road salting leads to high concentrations of chloride and sodium in local waters. Increased chloride in drinking water supplies can lead to more rapid corrosion of drinking water infrastructure, such as private and municipal wells and pipes. This decreases the safety of drinking water. Increasing sodium concentrations is also concerning for those with hypertension.

To top it off, salting can lead to faster rates of corrosion of bridges and roads, putting road infrastructure at risk as well.

Lacking: efforts to reduce road salting

De-icing salts were first used in the 1940s in North America, and as its use exponentially increased with urbanization and road expansion, sodium chloride became the most popular. With increased understanding of risks to the environment and human health over time, efforts to reduce road salt use include using alternatives such as beet juice.

However, these alternatives can be expensive and can come with their own pitfalls, like introduction of more nutrients into aquatic systems. Understanding how much salt needs to be applied, and when, is a crucial part of salt and ice management. Additionally, shifts in perspective of ice safety can be made. In some regions for example, snow tires are required for vehicles while people use chains, boot spikes and other personal traction devices.

At a recent salt summit, held by the Lake George Association in New York, a speaker adequately described our current relationship with salt as “oversalting comes from a place of love, concern and want of safety,” because icy conditions are considered unsafe.

However, short-term prospects of ice safety blind us to the love, concern and want of long-term safety of our drinking water supplies and environmental integrity.

Mitigating our winter road salt addiction

We need to first recognize the year-round impacts our winter choices can have, and then take action to reduce the impacts. We can share the impacts of road salt and the individual actions we can take, such as understanding how much salt needs to be put down on our private properties, adjusting our expectations of winter roads and using snow tires and boot spikes to provide an added layer of safety.

At a larger scale, mandatory certifications for salt application can provide training for snow removal companies, and have substantial incentives if designed properly. For example, the New Hampshire Green SnowPro Certification provides limited liability relief for snow removal contractors if they are certified.

This ensures snow management companies are protected and their training programs are recognized as safe. Other organizations, like the Smart About Salt Council, provide the opportunity for certifications, training and general knowledge on salting.

Unifying the snow removal industry and scientific researchers is necessary to understand the full impact of salts, as understanding where salt is applied and how much is used is an important component of environmental modelling. This unification can be casual, such as through interviews.

It can also be more formal such as through joint research or educational initiatives, like the Partners in Project Green resource development for industry to understand road salt impacts and resources for more information.

Road salt pollution is an issue which can be acted on immediately, rather than relying on technological advancements, as action can be taken at the individual, the federal and all levels in between. This action should be taken swiftly to ensure a less salty future for our freshwater streams, lakes and drinking water.

So this winter season, when you hear the crunch of your boots on road salt, know that, although the salts we use now may not be visible after winter, the effect they have on the environment and our drinking water is year round.

Road Salt in Cities Shows Links to Saltier Water | International Joint Commission (ijc.org)

Separate studies in Ontario and Ohio suggest that increasing urbanization over the past 40 years has been a driving factor in freshwater rivers getting saltier.

Over the decades, southern Ontario and Ohio’s Cuyahoga River watershed urbanized rapidly as cities grew across the landscape. More concrete roads, sidewalks and other infrastructure were treated in the winter months with road salt to prevent ice from forming.

Road salt typically consists of magnesium chloride, potassium chloride or sodium chloride. Over time, salt-laden water runs off either into the sewer system or directly to streams and rivers. Additionally, calcium chloride also is used to suppress dust on roads, while aluminum chloride is used to treat impurities from wastewater.

While it is unlikely that salt concentrations in the Great Lakes would render the water undrinkable for people, too much chloride (a catch-all category for these salts) can affect the taste.

And,  high enough concentrations of chloride in streams and lakes, can affect native species such as lake trout or lake whitefish, which have limited abilities to survive in saltier, brackish water. Saltier water also can make it easier for nonnative species, such as red marine algae or the round goby, to establish themselves and spread.

Since 1974, the US Geological Survey has been working with Ohio’s Heidelberg University to sample tributaries entering Lake Erie or the Ohio River.

Douglas Kane, a Heidelberg researcher, went through decades of data for the Cuyahoga, Maumee and Sandusky rivers to see what the long-term trends are regarding chloride in the water.

The Cuyahoga River stood out, Kane said, with increasing chloride concentrations over time.

“In the beginning of the record, the (amount of chloride in the) Cuyahoga was on average 100 milligrams per liter (mg/l) in the winter,” Kane said. “But now it’s around the 200 mg/l range, so it’s at least twice what it was, and compared to the other rivers—it’s much greater.”

Canada and the United States have water quality criteria for chloride to protect aquatic life.

Under US guidelines, 230 mg/l is the chronic exposure limit for freshwater species, with 860 mg/l for the short-term exposure limit. Canadian guidelines are stricter, with 120 mg/l for chronic exposure and 640 mg/l for the short term. These guidelines are considered too high by Canadian officials to adequately protect the wavy-rayed lampmussel, a species native to Lake Erie and its tributaries.

Kane said the Maumee and Sandusky rivers maintained a steady amount of chloride in the water over the monitoring period–about 40 mg/l. Both of these are largely rural streams, whereas the Cuyahoga River flows through the developed areas of Akron and Cleveland.

Kane said this gives a pretty good indication that increasing chloride amounts are linked to urban and suburban development along the Cuyahoga basin over the past 40 years. This was not an isolated issue, he added, as Environment and Climate Change Canada’s monitoring stations on the Niagara River at the eastern end of Lake Erie also found chloride concentrations increasing over this same time period.

Similar signals have appeared on the northern shore of Lake Erie in southern Ontario. A study published in Environmental Research Letters in August 2021 looked at datasets going back to 1964 collected by the Ontario Provincial Water Quality Monitoring Network. Researchers primarily sampled most of the waterways  in the summer, though they focused the project on those that also had ample winter samples—about 10 streams and rivers with data from 1965-1995 and 15 from 2002-2018. Only two sites, Moira River and Jackson Creek, appeared in both sample groups.

Similar to Ohio, this study found chloride concentrations increasing in urban regions of the province year-round, said project leader Bhaswati Mazumder, a doctoral student at Ryerson University. But rural streams and rivers also consistently had levels of chloride that held steady or increased seasonally, with higher rates of change in winter.

Some watersheds maintain elevated chloride concentrations into the summer, when no road salt is being applied, and in few cases the summer concentrations are increasing, Mazumder said. The study tried to parse how much of these upward trends are due to urban growth, changes in road salt application rates, and/or legacy chloride contamination stored in the regions’ rich soils and groundwater. Urban growth did not explain all of the upward trends, which suggests that changes in management and/or legacy chloride are a big part of the problem.

Information from the Provincial Water Quality Monitoring Network was used for Mazumder’s study. Credit: Bhaswati Mazumder

“It seems like what we’re putting in is not going anywhere,” Mazumder said. “It’s just delayed transport in the subsurface, and then (the chloride is) slowly making its way to streams later on.”

Mazumder said future water quality models need to take long-term changes in streamflow into account given how dramatically flows can change based on the season and weather—particularly with climate change affecting precipitation patterns in Ontario and elsewhere. Part of an update would likely involve developing models specific to a stream and its flow pathways. Mazumder also noted the need for more accessible long-term flow data and water quality monitoring in Canada.

In Ohio, Kane plans on compiling Ohio Environmental Protection Agency data from additional waterways. This includes creeks and streams that feed into the major rivers he looked at to help pinpoint hot spots where chloride is coming in. Kane also hopes to obtain information for other waterways with high chloride levels, such as Wolf Creek, which runs through Toledo, and Coldwater Creek, an agricultural stream. Kane and his collaborators, Drs. Laura Johnson and Nate Manning from the National Center for Water Quality Research, are submitting their work to the Journal of Great Lakes Research.

It saves lives, but how does road salt impact the environment? (msn.com)

As winter gets into full swing, salt will be used across the country to make roads safe for drivers. How does it impact the environment?

Warren County DPW superintendent name to Adirondack Road Salt Reduction Task Force | | poststar.com

Warren County Public Works Superintendent Kevin Hajos has been selected to serve on the Adirondack Road Salt Reduction Task Force, an organization tasked to help find ways to reduce the use of road salt on highways.

Hajos has led a team at the Department of Public Works that has begun a program to use salt brine on roads in the winter to minimize the impact of snow and ice, and to help supply towns in the county with salt brine. Brine is considered more environmentally friendly and less expensive than salt,

He was nominated for the task force by state Sen. Dan Stec, R-Queensbury.

“I am honored to have been chosen to sit on this task force as we work to ensure protection of the lakes and waterways that are such an important part of our lives and economy here in Warren County and the rest of the Adirondacks,” Hajos said in a Warren County news release.

The 15-member task force has been asked to create a three-year pilot plan for road salt reduction practices. A final report on that study will be due to state legislators in the summer of 2024.

The task force will be chaired by the state Department of Environmental Conservation and state Department of Transportation.

“We are very proud of the work Mr. Hajos has done implementing new solutions to reduce the levels of salt that run off into Lake George and our other water bodies,” Warren County Administrator Ryan Moore said. “His knowledge and experience will be of great value to this important task force.”

Warren County Board of Supervisors Chairwoman Rachel Seeber said Hajos has been “a leader in the region’s efforts to curb the use of road salt on our highways while continuing to keep our roads safe during winter weather,” and she thanked Gov. Kathy Hochul for recognizing Hajos’ expertise.

“We are eager to see what steps this task force will recommend to further protect our environment from the impacts of road salt,” she said in the release.

A news release from the Governor’s Office identified 10 of the task force members, who, in addition to Hajos, include former state Department of Environmental Conservation Commissioner Joe Martens; Adirondack Park Local Government Review Board Executive Director Gerald Delaney; Adirondack Council Vice President for Conservation Megan Phillips; ADKAction Executive Director Brittany Christenson; Kristine Stepeneck, a member of the International Joint Commission — the U.S. and Canada’s watershed quality organization; Philip Sexton, the founder and managing director of WIT Companies, a sustainable winter management company; Robert Kafin, who chairs the Council on the Environment of New York City; and Hamilton County Superintendent of Highways Tracy Eldridge.