Our use of rock salt threatens the delicate web of life
We just spent 10 minutes taking a survey, and we urge you to do the same.
The survey, on the use of rock salt, is from the state’s Department of Conservation, which says it wants to understand how New Yorkers use salt and also wants to gauge public awareness about the potential environmental and health impacts of salt overuse.
Results of the survey, the department says, will help it tailor future outreach and education to reduce overuse of rock salt on roads, parking lots, and sidewalks.
The survey, which can be answered anonymously online, has 27 questions. Here is the link: https://www.surveymonkey.com/r/WinterRockSalt.
Some of the questions are about the survey-taker: your ZIP code, your age, where you get news on environmental issues, what you do for work, if you own or rent your home, if your home is rural or suburban or urban, if you get water from a well or a municipal source, if you use snow tires, what form of snow and ice removal you use at home, and if you’d be willing to reduce your use of rock salt by using brine or sand instead.
The other questions ask how familiar you are with the issue of rock-salt pollution and its effect on the environment and public health and how much you are concerned about those effects as well as if you would support solutions that reduce the use of rock salt while maintaining public safety.
“This short survey will help DEC learn more about how New Yorkers use rock salt at their homes, businesses, municipal buildings, and other properties to help target effective outreach and meet salt reduction goals to protect lands and waters,” said Sean Mahar, the DEC’s interim commissioner, in a press release promoting the survey.
Mahar explained that his department is working with state and local agencies to implement the Adirondack Road Salt Task Force’s recommendations and explore ways to balance safety with the protection of public health and sensitive ecosystems.
We wrote a year ago on this page about the in-depth report on road-salt reduction, which was released last September, after the state legislature in 2020 established a task force to review best management practices for safe winter driving.
The task force report, at its start, outlines a conundrum that would be familiar to any Adirondacker and also serves as a metaphor for our modern era: the tension between protecting the safety of people and protecting the environment.
“On the one hand,” says the report, “the all-weather use of transportation corridors and privately owned paved surfaces is essential, and the application of road salt to roads and other surfaces to control ice and snow for the safety of the traveling public has become an established practice.
“On the other hand,” it goes on, “the protection of public health and the environment from contaminants is also essential, and the migration of road salt onto nearby lands and waters has detrimental effects on natural resources, humans, property, and infrastructure.”
The 6-million-acre Adirondack Park, with nearly half of it “forever wild,” typically has a longer snow and ice season than other parts of the state as well as sensitive ecosystems.
Road salt, which is 40 percent sodium and 60 percent chloride, rusts not just vehicles but bridges and the reinforcing rods in concrete. One study estimated that salt corrosion costs the United States $16 billion to $19 billion per year.
Salt wasn’t widely used on roads in the United States before World War II. And, since 1975, use of road salt has doubled. Besides being used on paved roads, road salt is applied to sidewalks, parking lots, and driveways.
The problems go beyond the damage to valuable infrastructure. Road salt accumulates in both surface and groundwater, which is harmful for humans as well as plants and animals. It can take decades for road salt to flush out of a watershed.
Besides the dangers of people drinking salty water, high chloride increases the corrosion of poisonous lead from old water pipes, according to research by the federal Environmental Protection Agency and the United States Geological Survey.
Any of us driving on major highways can see the effect salt has had on roadside vegetation, but we don’t often see more sinister effects. The environmental impact can be far-reaching and irreversible.
When the ice melts, the salt flows into surrounding streams, lakes, and grassy areas. The salt water is more dense than fresh water so it pools at the bottoms of lake and ocean beds. This deprives amphibians and fish of needed nutrients trapped beneath the salt cloud.
The task-force report notes that the environmental impact from road salt can be long-term as it can leach into groundwater. Existing water quality standards may not be protective enough to prevent impacts to the Adirondack Park’s sensitive natural resources and ecosystem, the task force found.
A study that traced salt levels in the Mohawk River, from 1952 to 1998, discovered concentrations of sodium increased by 130 percent and chloride increased by 243 percent; road salt was the primary reason as the surrounding area became more developed. The United States Geological Survey estimates that 40 percent of the nation’s urban streams have chloride levels that exceed safe guidelines for aquatic life, largely because of road salt.
Many studies have found that chloride from road salt can kill plants, fish, amphibians like frogs and salamanders, crustaceans, and other organisms. Also more salt in the water of lakes and ponds make it denser and affects circulation, keeping oxygen from reaching the bottom layer of water.
Road salt can also change the chemistry of a body of water, reducing the nutrient load.
One of our New Scotland readers, Edie Abrams, pointed us to a study just published in Science of the Total Environment, which looks at the harm road salt causes for freshwater plankton and, in turn, the food chain.
“In freshwater ecosystems, the nexus of the algal-zooplankton energy pathway is critically important for food webs because it transfers energy from primary producers to higher-level consumers,” the study says, noting, “The use of road deicers has led to the stark decline in biomass of many freshwater zooplankton species resulting in trophic cascades, altered community structure, and behavioral changes.”
Although the authors note that here in the United States, the EPA has set thresholds for salt contamination in freshwater as do many countries around the world, they say their work shows these water guidelines need to be re-evaluated to better protect freshwater ecosystems.
As human beings, we have a tendency to think of ourselves as the center of the natural world. It is easy to read the study on the harm to freshwater plankton and think that human safety — people traveling on roads in winter — is more important.
Really though, we humans are just part of an intricate web. Since at least the age of industrialization and perhaps since the start of farming, we homo sapiens have warped the natural order.
This has become clear to most of us in recent years as we have witnessed the catastrophic effects of climate change — from flood and drought to fires and hurricanes.
Some scientists consider our era a new geological epoch, the Anthropocene. Homeo sapiens in just the 200,000 years we’ve lived on this four-and-a-half-billion-year-old planet Earth have wrought changes that may be irreversible.
It is not just the big changes most of us acknowledge — like the greenhouse gasses melting the polar ice or the plastic pollution littering the oceans or the rapidly declining number of species — but so many others we are not even aware of.
One stunning example is the link between the declining bat population and rising infant mortality.
How, you may wonder, could these possibly be related. The simple explanation is: Bats eat insects. As bat populations declined, farmers used more pesticides.
In counties where farmers used on average 31.1-percent more pesticide, infant mortality rates rose by 7.9 percent on average, says a study published in the journal Science last month.
“Scientists have long theorized that declines in biodiversity and continued degradation of ecosystem functioning would lead to meaningful negative impacts on human well-being,” writes the study’s author, Eyal G. Frank, in his introduction.
When farmers replaced the biological pest control that bats had provided with toxic compounds, more human babies died.
“Biodiversity loss is accelerating, yet we know little about how these ecosystem disruptions affect human well-being,” Frank wrote. He documented just one, measurable example.
How many others have not been documented? And how many others will arise in the years ahead?
The Adirondack Road Salt Task Force report highlighted the tension between protecting the safety of people and protecting the environment.
We believe the two are interrelated. If we protect the environment, we will, in the long run, be protecting ourselves.
With this in mind, each of us needs to do what we can. You can start by taking 10 minutes to fill out the DEC survey.
Then, when the snow inevitably falls, you can shovel it before it turns to ice. You can use beet juice or coffee grounds or sand instead of rock salt to make walking into your home safe.
You can check in with your town’s highway department and see if they are using measures that reduce the use of rock salt. We’ve seen the road in front of our home laced with a salt solution ahead of a predicted storm.
A Cornell study showed that truck speed had a profound effect on how much salt was lost to bounce and scatter. A truck driving at 25 miles per hour lost only 9 percent; a truck at 35 miles per hour lost 32 percent, and a truck driving at 45 miles per hour lost 45 percent of its salt to bounce and scatter.
A variety of other tactics are being tried by highway departments across the nation. Many are using a 23-percent salt-brine solution to pre-treat roads before the start of a storm, which may result in a 75-percent savings in total salt applied.
Some departments are pre-wetting salt before putting it on the roads, which can reduce salt infiltration to aquifers by 5 percent and also reduces spray and kick-up of salt grains.
Several states adjust levels of service for conditions. In Vermont, for instance, the transportation department uses the slogan “safe roads at safe speeds,” meaning roads are not necessarily bare after a snowstorm.
In Minnesota, the department of transportation is pioneering the use of what it calls “living snow fences,” barriers made of trees, shrubs, and native grasses that can prevent snow from drifting onto roads.
By filling out the DEC survey you are helping our state government implement some of the task-force recommendations.
You can also look to the federal government to see that the congressional representatives as well as the president you elect is willing to protect the environment with needed legislation in the wake of a Supreme Court decision this year that curtailed the power of agencies like the EPA to interpret ambiguous federal laws.
The study we cited here on plankton, along with other studies, shows that the current federal guidelines on salt are not adequate.
We need to remember that we humans are part of a web of life. The farmers who were using pesticides on their crops were doing so within government guidelines; no one knew it was killing babies.
Our irresponsible actions not only harm other species but will also ultimately harm ourselves.