By Diana Kruzman for Grist.
Broadcast version by Mike Moen for Minnesota News Connection reporting for the Grist-Public News Service Collaboration

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"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."

Diana Kruzman wrote this article for Grist.

Support for this reporting was provided by Solutions Journalism Network.


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A new, high-tech wastewater treatment incinerator, used in only a few states, is on the wish list for one Michigan city.

Former state Representative - now Mayor of Warren - Lori Stone is asking her former colleagues in the Environment, Great Lakes and Energy Subcommittee for up to $100 million to upgrade her city's wastewater treatment system.

Warren's current plant was built in 1957 and serves over 137,000 residents. The new incinerator would oxidize organic matter contained in the sludge.

Warren Wastewater Treatment Plant Director Donna Dordeski said the old system is failing.

"One of the hearths of the furnace collapsed and failed, and we couldn't use it any longer until repairs had been completed," said Dordeski. "So, from the beginning - and all the waiting, getting the contractors and repairs completed - it took four months."

Dordeski said they're approaching the final steps of getting permits for the project. And they're still seeking funds, at the state and federal levels - including infrastructure grants that may be available.

The city has around 500 miles of sanitary sewer pipes to ensure its wastewater is treated and disposed of properly. Dordeski said when the current system breaks down, it affects local residents. Trucks have to pick up and carry sludge back and forth through their neighborhoods to nearby landfills.

"That's a 24-hour operation," said Dordeski. "We usually have several trucks. Its a continuous process, five days a week, where we process the sludge and those trucks have to be nearby, available, be loaded, exchanged for a new one. So, that's what has to happen when our incinerator is not operational."

Michigan has 95 wastewater treatment plants.

Warren's mayor believes if the new incinerator is approved, the city will have the opportunity to be the proving ground as a pilot program for this technology.




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As Wyoming and other states grapple with shrinking Colorado River water levels - new research pinpoints how much water is being diverted to feed cattle, to sprawling desert cities, and the river's 40 million other stakeholders.

The stakes are high in a time of persistent and widespread drought.

Brian Richter - president of Sustainable Waters - said if Upper Basin states can't deliver the volume of water required under a century-old agreement, Lower Basin states could force the issue with what's known as a compact call.

"The likely result would be that the Upper Basin states, including Wyoming, would be forced to use less water," said Richter, "so that more water could be flowing into Lake Powell and downstream into the Lower Basin."

Researchers found that in Upper Basin states, cattle-feed crops soak up 90% of all irrigation water - which is three times the amount that goes to all cities, towns, commercial and industrial uses combined.

Just 19% of the Colorado River feeds the wetlands and riparian areas wildlife depend on.

Richter noted that cities in Utah and along Colorado's Front Range are at risk because they have very low priority for accessing water under the 1922 Colorado River Compact.

Despite calls for closing off spigots used exclusively for cattle feed, Richter said blaming any single user is counter-productive.

"Farmers and ranchers are growing the things that people want, and are willing to pay a necessary price for," said Richter. "So they are just responding to consumer demands."

He said he believes the new data could be an important tool for Colorado River stakeholders as they work to build a long term plan to bring the total use of water back in balance with what nature provides.

Richter said right now, water use is at least 10% to 15% over that limit.

"We need a long range plan that says how much water do we want to use in the cities? How much water do we want to use on the irrigated farms? How much are the industries going to need?" said Richter. "And until we do that long range plan, we are just going to be reacting to these water shortages on a year-by-year basis."




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Colorado lawmakers are considering legislation to restore protections to key waters and wetlands struck down by the U.S. Supreme Court last year in a decision leaving more than half of the nation's water supply at risk of industrial pollution.

Margaret Kran-Annexstein, director of the Colorado chapter of the Sierra Club, said House Bill 1379 is in sync with Colorado voters, pointing to a recent survey which found nearly nine in 10 voters want to limit damage and pollution from development, industry and mining on wetlands and streams.

"Recent polling has found that massive majorities of Coloradans, whether they are Democrat, Republican or Independent, really support common sense water protections that would happen under this bill," Kran-Annexstein reported. "I think we can all agree that clean water is a necessity."

A coalition of conservation groups support the measure to create a permitting program for responsible development through the Colorado Department of Health and Environment.

Last month, Sen. Barb Kirkmeyer, R-Brighton, introduced an alternative proposal supported by the homebuilding industry, which would require a new division and staffing in the Department of Natural Resources.

Kran-Annexstein stressed clean, reliable water resources drive the economy and are vital for the health of communities. She believes the high court's ruling, claiming some waterways do not have significant connections to watersheds, was a win for corporate polluters who want to avoid permitting.

"In Colorado we know that there are a lot of streams and rivers and wetlands that run dry for certain parts of the year," Kran-Annexstein pointed out. "This ruling said that those waterways don't deserve protections and they don't count, just because they are seasonal."

Mountain states like Colorado are the source of drinking water for some 40 million Americans living in downslope states and Kran-Annexstein said the House bill is an opportunity to pass important and necessary protections after last year's Supreme Court decision.

"This decision left half of the waters across the United States unprotected by the Clean Water Act," Kran-Annexstein emphasized. "And really left it to states to make their own laws to protect state waters. And now it is the responsibility of states to step up and close that gap."