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Road Salt: Way Too Much of a Good Thing

Samantha Briggs and Emily Bialowas
Outdoor America 2020 Issue 1
Salt truck

With the unofficial start of summer upon us, winter, and the snow, ice, and road salt that come with it, seems like a distant memory. But, has that road salt (in the form of chloride) made a lasting impression on the streams flowing through your backyard?

You may have already started to make some connections about the impact of road salt on your cars, the environment, and our infrastructure. If road salt can corrode metal and kill vegetation, what is it doing to our streams and rivers? Or worse, what is it doing to drinking water sources and, ultimately, our health?

The Izaak Walton League is leading a nationwide campaign to help local volunteers document those impacts and advocate for changes that protect drivers and pedestrians, water quality, and public health. In less than three years, our Winter Salt Watch campaign (sparked by an intern concerned about a pile of salt dumped a few feet from the creek running through League property) has grown exponentially to include hundreds of volunteers nationwide. Through Salt Watch, we are exploring not only how pervasive road salt pollution is, but how states and communities are taking steps to better manage road salt usage.

The Science of Salt

Up to 20 million tons of salt are spread on roads, parking lots, and sidewalks every year across America in the name of road safety. Protecting drivers and pedestrians in the winter is paramount, but road salt used in excess can be costly for taxpayers and harmful to water quality – while not making roads any safer.

Dissolved salt runs off hard surfaces when snow and ice melt. Some of that runoff ends up directly in nearby streams and rivers. Some soaks into the ground, leaching into groundwater supplies or flushing into streams, rivers, and lakes during spring and summer rains, causing chloride spikes. Even if we quit using road salt today, the salt already in the ground can persist for decades, and the salt content in our streams will rise as salt continues to percolate through the soil.

Why is this harmful? Almost all freshwater fish cannot adapt to salt in the water – there is a reason they are called freshwater fish. Salt can also be toxic to the aquatic macroinvertebrates that fish and other stream dwellers eat and that we look for during stream monitoring. Road salt on your driveway or street can kill the plants in your garden. Dissolved salt in groundwater can kill streamside plants, making erosion and runoff an even bigger problem.

Moreover, doctors have become increasingly concerned that as road salt infiltrates our drinking water supplies, it can cause problems for people with high blood pressure because water treatment plants are not equipped to remove the extra salt. Desalinization equipment is cost-prohibitive for most water treatment facilities, so removal of salt from drinking water is generally not an option.

Road salt can hurt your wallet too. Rust damage due to road salt can shorten the life of your car. Road salt and its application cost the U.S. some $2.3 billion a year – much of that paid through your tax dollars. Between the health effects, impacts on wildlife, and monetary costs, states and community groups are looking for alternatives.

Minnesota: A Model State

Minnesota averages 40-60 inches of snow every year (up to 80 inches in Duluth), so most residents are prepared for whatever snowfall may come their way. This is thanks in part to the state agencies working to keep the roads safe, including with the application of road salt. In the “Land of 10,000 Lakes,” 75% of residents depend on groundwater for drinking water supplies. Decades of salt application have elevated chloride levels in drinking water and over 50 lakes and streams are impaired to the point of being dangerous for aquatic wildlife. That is why Minnesota was motivated to change road salt practices and now leads the nation on best practices for road salt application.

Taken together, these efforts are paying off in Minnesota. Municipalities across the state have reduced salt use between 30-70% while maintaining road safety.

The Minnesota Pollution Control Agency (MPCA) has been working to control road salt usage for over 20 years – without sacrificing public safety.

The reason: “Chloride is so persistent,” says Brooke Asleson, chloride coordinator for the MPCA. “That chloride you see today could be salt from 5-10 years ago making its slow way to the stream or the lake. And we’ve been putting it down every year. Even as we are cutting back, to actually see a turnaround in water quality trends is going to take some time.”

The agency’s effort to reduce road salt usage emphasizes a voluntary certification program for public and private salt spreaders. The goal is to help winter maintenance employees understand the impacts of salt, especially when it is mismanaged. For example, they learn how their equipment really works, including how to calibrate it so minimal road salt is applied while still upholding rigorous public safety standards. Once employees become certified and understand the impact on water quality and public health, they are motivated to utilize best practices when managing and applying road salt. They now understand the connection between their actions and the environment. According to Asleson, “We start with helping [salt spreaders] understand the environmental issues with deicing salt. Sometimes just helping to create that awareness with them will spark a change.”

Beyond the certification program, the MPCA has also developed a Smart Salting Assessment tool (SSAt) to help winter maintenance professionals pinpoint ways they can reduce salt application. The SSAt will give them a green, yellow, or red score for their own practices, as well as provide simple solutions for over-application. For example, if a driver has some salt left in a public works truck at the end of their route, what should they do with it? Rather than do another pass over a road and over-apply, simply return to the shop and put it back in the salt pile for use in the next winter storm. Proper storage and covering of road salt will also give a green score on the SSAt.

Taken together, these efforts are paying off in Minnesota. According to the MPCA, municipalities across the state have reduced salt use between 30-70% while maintaining road safety.

Minnesota also has a multi-pronged approach to testing waters for chloride pollution. State staff monitor water quality in lakes, rivers, wetlands, and streams, and MPCA supports a network of volunteer monitors throughout the state. This summer, based in part on the success of Winter Salt Watch, the League is partnering with MPCA to expand volunteer monitoring of high chloride levels in lakes around the state and to raise public awareness about how road salt is a serious water quality problem.

Myths About Road Salt

MYTH: You should feel the crunch.

FACT:If it’s crunching, it’s too much/not working. Salt only works to melt snow and ice when it dissolves. If you are crunching on salt after snow has fallen, there is too much salt on the ground.

MYTH: It’s easier to salt than to shovel and plow.

FACT: It’s significantly cheaper and more effective to shovel and plow early and often. Salt only melts snow at the very top and bottom layers of snow, and if the ratio of water to salt is too high it will be diluted and not work. That means you put a lot of expensive salt down instead of taking a few passes with the shovel or plow.

MYTH: The “problem salt” is sodium chloride. Alternatives like magnesium chloride or calcium chloride are better for the environment.

FACT: Magnesium chloride and calcium chloride are still “salts” and still put chloride in the ground. They also work best at colder temperatures, meaning they are only appropriate to melt snow and ice at 15° F or colder. If you live in a warmer place, these salts won’t work when the weather is just below freezing.

Saltwatcher Joyce Ely submitted a salt watch post showing how oversalted this street was in Pennsylvania!

Excessive salt

Expansion of Best Practices to Other Regions

Other states are taking notice of these successes and following suit. For example, New Hampshire has modeled a training certification program after the one developed by MPCA. Even regions that have less snow in the winter, such as Northern Virginia, are taking steps to improve road salt management.

Virginia presents a unique challenge for road salt management because winter storms frequently have a mix of snow and rain. Road salt is often applied in anticipation of a snow event and can be immediately washed into local streams and rivers when that snow turns to rain. In 2018, the Virginia Department of Environmental Quality (DEQ) launched a pilot effort to address this problem by developing a Salt Management Strategy (SaMS) for densely populated Northern Virginia. The SaMS is a collaborative process involving local governments, state agencies, non-governmental organizations (including the Izaak Walton League) and concerned citizens. The League was invited to participate because of our success with Winter Salt Watch and the possibility that League volunteers could be used for monitoring the effectiveness of the strategy going forward.

The Northern Virginia SaMS has some specific goals: increase public awareness and change perception and behavior when it comes to road salt application; and improve water quality by reducing road salt (or chloride) pollution. Will Isenberg, from the Virginia DEQ, believes that reducing the amount of salt applied will help reach overall water quality goals. “If you are more efficient with your salt use, you are using less, you are salting less, it’s a safe assumption that less is getting into the environment and ultimately you will see a change in the [water quality] pattern.” Isenberg goes on to highlight how the real challenge is “striking that balance, trying to keep the safety benefits salt provides, but at the same time trying to find areas where we can be more efficient and effective.” In other words, reducing road salt application without sacrificing public safety.

According to Isenberg, in terms of growing public awareness and stakeholder participation, the Northern Virginia SaMS has already been a success. “One of the most beautiful things I have seen through this whole process is a lot of people who were very hesitant and concerned in the beginning, they have jumped on the bandwagon, they are excited about making these changes because they can see the bigger picture now.” In many cases, the changes to which Isenberg refers are practices and training like those used in Minnesota. As for the water quality impacts of this increased awareness, as we have seen from Minnesota, it may be many years before that decrease in road salt application is detectable in streams.

Kevin Roth
Salt Watch reading

Citizens Action – An Integral Piece of the Puzzle

While it seems like some states are doing a lot to combat the road salt pollution, don’t sit back in your seats just yet. Citizen action is driving change in road salt application across the country, even in frontrunner states like Minnesota.

Stop Over Salting is a small but mighty citizen action group based in the Twin Cities region (Minneapolis and St. Paul) of Minnesota. Sue Nissen, a leader of Stop Over Salting, reflects on the birth of the group and how it all came to be. “When we heard about salt and the damage that it did, we started thinking about all the salt that would be put down the next winter, and we couldn’t live with ourselves. We had to start raising awareness, because we realized that we hadn’t known what the consequences were.”

To combat the consequences of road salt, they started meeting with local officials in Edina, Minnesota, to express concerns. Their persistence paid off, and a workgroup within the city was established. The workgroup advocated at both city and county levels and with private applicators and property managers. Through that process, they discovered the challenges to salt reduction, and how ingrained salt usage is not only in the minds of the public, but also in the minds of the applicators and property managers.

One of the things the Stop Over Salting group noticed was the fear of liability among road salt applicators. Because there is a perception that more salt is better and safer, there is a strong belief among building managers and applicators that if they don’t put down a lot of salt, then they are liable to be sued and a jury will rule against them on the misperception that they didn’t put down the right amount of salt.

“Limited Liability” legislation, designed to protect applicators and building managers from that kind of slip and fall lawsuit, had periodically been introduced in Minnesota’s legislature. Stop Over Salting saw this as an opportunity to become involved in public policy. They advocated for passage of this legislation for two years. Although it did not pass, volunteers started a dialogue with officials in many cities and counties in the process and raised public awareness about the impacts of road salt across the state. Additionally, they are working on city ordinances for improved salt storage, cleanup, and contracting with companies that use best management practices for snow and ice maintenance. “Lots of other people that care about clean water didn’t know what the consequences [of road salt] were,” reflects Nissen. Through education and policy, citizens do indeed have the power to make an impact.

On the other side of the country, citizens in the Philadelphia area are taking action to reduce road salt pollution. The Pennypack Ecological Restoration Trust was founded in 1970 as a membership-based environmental group whose primary mission is to improve water quality in Pennypack Creek. Kevin Roth, education and outreach coordinator for the Trust, thinks back to 2018 when they first began noticing rising chloride issues in their region. Their network of in-stream remote sensors showed chloride levels triple after a surprise early snowstorm when the local township public works department did not salt at all.

Roth and his team quickly realized that a major part of the problem was salt application by private businesses and homeowners. They learned about the League’s Winter Salt Watch program and saw it as a great opportunity to engage the public and their volunteers on chloride pollution. “We saw it as a way for regular homeowners to learn that a) this is a problem, and b) there is something you can do about it.”

The success of Winter Salt Watch in the Philadelphia region, largely due to the coordinated efforts of local watershed organizations, including Roth’s, has produced excellent results in terms of participation and increasing awareness. Last year, volunteers in the region gathered approximately 85 tests in two watersheds (Lower Delaware and Schuylkill). Forty-three tests documented chloride levels significantly above the natural level and 20 reports were over the toxic threshold of 230 parts per million (ppm) established by EPA. This year, an extremely mild winter meant there have been only seven results exceeding the toxic threshold. This shows the very direct correlation between road salt usage and water quality.

These results, from both last year and this year, have even gained media attention. We asked Kevin Roth why Philadelphia news sources (the “Philadelphia Inquirer” newspaper and the local radio station WKYW, among others) had covered Salt Watch so widely. Roth said that water quality is an issue that residents pay attention to because of the Delaware River Watershed Initiative, which is a regional water quality monitoring effort with a strong advocate base.

This is just the beginning of the chloride crusade for Kevin Roth, the Pennypack Ecological Restoration Trust, and their volunteer base. “This year we are starting with the community and getting them to tell their friends and neighbors,” says Roth. Next, they will be engaging and educating businesses and local government entities to raise awareness and create change when it comes to road salt practices.

“We are hoping there can be small fixes with the townships,” Roth concluded. “The Pennsylvania Department of Transportation is still a stretch for us, but we want the townships to be able to at least make some small basic changes… get the simple problems out of the way first and then convince the scientists and researchers to come up with alternatives.” Small changes, big impact.

Salt Watch Results in the Northeast

Winter Salt Watch – Part of the Solution

Reducing road salt usage while maintaining public safety requires collaboration among governments, the private sector, and volunteer advocates. The League’s Winter Salt Watch campaign empowers volunteers to document the problem and advocate for best practices that have proven effective in the harshest winter conditions.

In just the third year of this campaign (winter 2019-20), the results are impressive. The League distributed over 900 test kits and volunteers across the country submitted almost 700 test results – almost doubling the previous winter’s kit distribution and response rate. Even in a mild winter for much of the country, watersheds in urban and suburban areas show higher chloride readings than those in rural areas. Of the results received, 29% measured unusually high chloride levels, and another 10% documented levels toxic to aquatic life.

Even in the summer months, we are not out of the woods when it comes to chloride pollution. Testing this spring and summer is essential to documenting the long-term impacts and identifying hot spots where chloride pollution persists at high levels. Last year, volunteers found chloride concentrations well above the level dangerous for fish in May, June, and July – in large part because salt continued to leach out of the soil around and in streams.

These results can be used today to influence salt application next winter. For example, volunteers can provide the hot spot information to local public works departments or property management companies and suggest reducing application in the specific areas. Or they can share results with the local public health officials because it documents locations that can contribute high levels of chloride pollution to local drinking water supplies.

If you would like to see how chloride is affecting your stream or river, visit iwla.org/saltwatch for more information and to request a Salt Watch kit. If you already have a Salt Watch kit, continue to use your test strips in your region periodically, even as the weather warms.

Road salt pollution is a prevalent issue around the country, which is why states like Minnesota, New Hampshire, and now Virginia are strategizing to reduce road salt application while also keeping drivers safe. Unfortunately, not all states are working towards solutions for over-application of road salt – but that is where you come in! Sometimes, even a small, simple action (such as submitting chloride data to the Salt Watch national map) can put pressure on the “powers that be” and make positive changes for water quality, public awareness, and our health, all while maintaining safety on the roadways.

What You Can Do Next Winter

  1. Sign up for Winter Salt Watch and take samples of your local streams during the winter months, and do not forget to submit your results!
    • The League will gather results on a monthly basis to show where there are road salt hotspots.
    • League staff will submit press releases with results to gain the attention of local media and educate the public.
  2. On your (or your business’) property:
    • Shovel or plow early and often during winter storm events so less salt needs to be used.
    • If you don’t need to clear it, don’t clear it! Driveways that are particularly wide might only need one lane cleared.
    • If the storm is gone and salt was used, you can sweep up excess salt and use it during the next storm event.
    • Plan ahead of storm events and stay inside during or immediately after the snow to give salt time to work and take the pressure off snow maintenance companies.
  3. Contact your local Department of Transportation or any private winter maintenance contractors:
    • Ask if they brine rather than apply rock salt for more effective coverage with less chloride pollution.
    • Ask if winter maintenance professionals undergo a training or voluntary certification program.
    • Let them know that you want water quality to be a balanced concern with public safety, and that extra salt does not make the public safer (see “Myths” above).

A young Saltwatcher samples a stream near his home in Virginia.

Boy in stream
Samantha Briggs is the IWLA Clean Water Program Director. Emily Bialowas is the IWLA Chesapeake Monitoring Outreach Coordinator. Emily also runs the Winter Salt Watch campaign.