Featured Post from Villanova University

Application of Road Salt Can Have Widespread and Long-Lasting Impacts, Says Villanova’s Steven Goldsmith, PhD

Feb 13, 2025

5 min

Streaks of white that coat roads and cars. Powdery footprints smudged into floors. It’s the time of year when much of the United States relies on road salt to keep ice at bay and accepts the nuisances that come with it. But beyond the inconvenience, all that salt has potentially serious, long-term effects on the environment, human health and infrastructure.


Steven Goldsmith, PhD, an associate professor of Geography and the Environment at Villanova University, researches topics in watershed biogeochemistry and environmental health. A focus of his lab is the study of de-icing practices on water quality. Recently, Dr. Goldsmith shared insights from his work, exploring the widespread consequences of road salt and potential solutions to reduce its harm.


Villanova PR: You have led or participated in research focused on the environmental impacts of road salt application, often locally, but with much broader implications. What have some of those studies found?


Steve Goldsmith: In 2022, we published a paper showing that salt—sodium in particular—is seeping into Philadelphia's water supply, and it's timed with snow melts. We found that if you drank a glass of tap water during the peak period in the winter of 2018-19, your sodium intake would be six times what the Environmental Protection Agency (EPA) recommends within a glass of water for someone on a low-sodium diet. We are susceptible in this region because most of our water supply comes from rivers, and the rivers receive that salt runoff. Some of our findings indicate this is a chronic issue and not limited to winter months. All that contaminated shallow groundwater causes the concentration to rise year-round, even in the summer.


In a recent paper, we discuss the issue of salt that lands on the side of the road. When it does, it infiltrates into soil, and then it goes into shallow groundwater before entering our streams. Oftentimes when salt is applied to the road and you receive that initial precipitation, you are left with runoff with salinity near the concentration of sea water, which is very bad for freshwater organisms.


PR: Have those studies found other impacts beyond those created directly by sodium?


SG: It’s certainly not just a sodium issue—it's also a chloride issue. Chloride does have a negative impact on aquatic organisms, but it can also corrode drinking water infrastructure. If you have lead pipes in that infrastructure, that can lead to a range of human health issues. Even just to prevent those problems, applying chemicals to protect from the corrosion of pipes increases costs.


Perhaps the worst part is when road salt infiltrates shallow soil and groundwater, the sodium is left behind preferentially in soils because it's displacing other positively charged elements, which could then go into groundwater. The elements it replaces are metals. If we have more salt runoff on the side of the roads, chances are, if we look in those streams, we are going to see higher concentrations of heavy metals like copper, zinc and even lead.


PR: You have mentioned the efficacy of brine. What is brine and why is it more effective than traditional road salt?


SG: If you’ve ever driven behind a rock salt truck, you probably noticed it pelts your windshield and shoots salt everywhere. A lot of that rock salt ends up following the natural trajectory of the road, which is designed to drain towards the sides to keep water from pooling. As soon as a snowstorm happens, it's going to melt and flow into the storm drain. That, of course, is bad for the environment, but also doesn’t help remove ice from the road.


With brine, the application is a diluted road salt with water mixture that is usually about 23 percent sodium chloride by volume, and it’s referred to as an “anti-icing” measure. The saltwater infiltrates the top layer of pavement and embeds in the roadway itself, which keeps ice from crystallizing when snow or water hits the surface.


To use an analogy, let’s say you have a large rock that you placed on top of the pavement, but you also have a quarter of that rock’s volume in sand. If you put that sand onto the pavement, it will permeate into nooks and crannies. That's the same idea here: use less material and in a way that makes it stick better to the surface and reduces the need to reapply as often during and after storms.


PR: What are potential positive impacts if municipalities switch from road salt to brine?


SG: There are limited studies on this, but it's been shown that if done properly, brining can reduce salt runoff into streams by anywhere from 23 to 40 percent. If it's 40 percent, you have almost cut the problem in half, and that lower peak salt concentration and runoff would have a profound positive impact on aquatic organisms that are downstream. From a cost standpoint—and I say this theoretically because there are other up-front costs associated with brining at the municipal level—if you reduce salt concentrations by up to 40 percent it means you apply a lot less and therefore spend a lot less.


PR: What can individuals do to decrease road salt runoff, and how much of an impact does individual use have?


SG: We can start by addressing the household salt application problem. Another one of our recent papers suggests that other impervious surfaces, like driveways, sidewalks and parking lots, are probably contributing even more than the roadway application. The best estimate is that individual or private contractor use could be over 10 times what you see on roads. For researchers, part of addressing this is trying to understand why people apply so much salt on their personal properties: are they afraid of lawsuits? Keeping with the Joneses? Are they not aware of ordinances that say you have to shovel within a certain number of hours, which would negate the need for salt anyway?


For homeowners and other individuals, one proposed solution is to use a coffee mug’s worth of salt for every 10 sidewalk squares. Think of it as a “low-sodium diet” to make sure you’re not overapplying. It’s a way we can limit our use of salt and do so in a way that doesn't jeopardize safety. These individuals can also sweep up salt applied before a storm that never materialized to use before the next one. This will prevent the possibility of rain needlessly dissolving the salt.


PR: Are there effective alternatives to road salt that individuals can use?


SG: The only truly effective alternative, unfortunately, is simply using less road salt. While some people apply sand, it also washes into local streams, causing environmental harm. Another option that has gained attention is beet juice—what I like to call the “Dwight Schrute” solution. Beet juice actually works better than road salt because its organic acids prevent ice from crystallizing at temperatures much lower than those at which rock salt is effective. However, from an environmental standpoint, beet juice contains high levels of nutrients, which can contribute to algae growth if it enters waterways. Additionally, recent studies suggest it may also be toxic to aquatic organisms. The growing consensus is that while some road salt is necessary, we need to use less of it.


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On Sunday, October 19, at 9:34 a.m., four masked individuals surged into the Louvre’s Galerie d’Apollon from a severed, second-floor window. Hurriedly, they smashed open two display cases, seized eight pieces of jewelry, then shimmied down a ladder and sped off on motorbikes toward Lyons. In seven minutes’ time, in broad daylight, they absconded with an estimated $102 million in valuables from the world’s most famous museum. This past Saturday, October 25, French authorities announced the first arrests in connection with the daring heist. However, despite the police’s progress, the country continues to litigate the matter—embroiled in discussions of heritage, history and national identity. Recently, Roderick Cooke, PhD, director of French and Francophone Studies at Villanova University, shared his perspective on the situation as well as the artifacts lost. Q: The Louvre heist has been described as “brazen,” “shocking” and a “terrible failure” on security’s part. Is there any sort of precedent for this event in the museum’s history? Dr. Cooke: Nothing on this scale has ever happened to the Louvre since its founding as a museum during the Revolution. The closest equivalent is the 1911 theft of the Mona Lisa by a former employee who claimed it should be returned to Italy. However, that was one painting, the heist was not committed by organized crime, and the Mona Lisa did not have the renown it enjoys today. The impact of the theft was thus lower, although it did cause major outrage and a sweeping law-enforcement response at the time. Ironically, that theft is often credited with making da Vinci’s painting the global icon it continues to be. Q: What has the reaction to this event been among the French people? DC: It’s harder to get a sense of reactions across French society, because so much of the aftermath has focused on the intellectual milieux’s opinions. And in those realms, it has immediately become a political football. Individuals positioning themselves as anti-elite or anti-status quo, such as Jordan Bardella of the National Rally party, have called the theft a “humiliation,” immediately tying it to French national prestige. Former President François Hollande has conversely and vainly called for the event to be de-polemicized, citing national solidarity. This is happening because the Louvre is one of the most visible manifestations of French soft power—the most-visited museum anywhere on Earth. As such, anything attacking its integrity becomes an attack on the nation, and how individual French citizens feel about the theft is closely tied to their broader view of the nation. Q: Several of the items stolen from the Louvre once belonged to Empress Eugénie. Could you share a bit of information on her story? DC: Eugénie de Montijo was a Spanish aristocrat who married the Emperor of the French, who ruled as Napoleon III between 1852 and 1870. 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President Macron referred to the stolen items as embodying “our history,” which is emblematic of the French state’s work to create a conceptual present-day unity out of the clashes of the past. At a time when France is arguably more divided than at any point since World War II, any unitary symbol of identity takes on greater significance. Q: Do you have any closing thoughts on the artifacts taken and what they represent? DC: I’d reemphasize the previous point about the smoothing effect of the museum display on the violent history that made it possible. Much of the reporting on the stolen jewels lists off the different queens and empresses who owned them, without giving readers a sense of the complicated succession of regime changes and ideologies that put those women in power in the first place. The relative stability of the last 60-odd years is an anomaly in modern French history. 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4 min

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A global team of researchers using the new X-ray Imaging and Spectroscopy Mission (XRISM) telescope, launched in fall 2023, discovered something unexpected while observing a well-studied neutron star system called GX13+1. Instead of simply capturing a clearer view of its usual, predictable activity, their February 2024 observation revealed a surprisingly slow cosmic wind, the cause of which could offer new insights into the fundamental physics of how matter accumulates, or “accretes,” in certain types of binary systems. The study was one of the first from XRISM looking at wind from an X-ray binary system, and its results were published in Nature—the world's leading multidisciplinary science journal—in September 2025. 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GX13+1 is a binary system consisting of a neutron star orbiting a K5 III companion star—a cooler giant star nearing the end of its life. Neutron stars are small, incredibly dense cores of supergiant stars that have undergone supernovae explosions. They are so dense, Dr. Neilsen says, that one teaspoon of its material would weigh about the same as Mount Everest. Because of this, they yield an incredibly strong gravitational field. When these highly compact neutron stars orbit companion stars, they can pull in, or accrete, material from that companion. That inflowing material forms a visible rotating disk of gas and dust called an accretion disk, which is extremely hot and shines brightly in X-rays. It’s so bright that sometimes it can actually drive matter away from the neutron star. “Imagine putting a giant lightbulb in a lake,” Dr. Neilsen said. “If it’s bright enough, it will start to boil that lake and then you would get steam, which flows away like a wind. 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Two Decades Later, Villanova Engineering Professor Who Assisted in Hurricane Katrina Investigation Reflects on Role in the Storm's Aftermath

Twenty years ago, Hurricane Katrina hit the southeastern coast of the United States, devastating cities and towns across Louisiana, Florida, Mississippi, Alabama and beyond. The storm caused nearly 1,400 fatalities, displaced more than 1 million people and generated over $125 billion in damages. Rob Traver, PhD, P.E., D. WRE, F.EWRI, F.ASCE, professor of Civil and Environmental Engineering at Villanova University, assisted in the U.S. Army Corps of Engineers' (USACE) investigation of the failure of the New Orleans Hurricane Protection System during Hurricane Katrina, and earned an Outstanding Civilian Service Medal from the Commanding General of USACE for his efforts. Dr. Traver reflected on his experience working in the aftermath of Katrina, and how the findings from the investigation have impacted U.S. hurricane responses in the past 20 years. Q: What was your role in the investigation of the failure of the New Orleans Hurricane Protection System? Dr. Traver: Immediately after Hurricane Katrina, USACE wanted to assess what went wrong with flood protections that had failed during the storm in New Orleans, but they needed qualified researchers on their team who could oversee their investigation. The American Society of Civil Engineers (ASCE), an organization I have been a part of for many years, was hired for this purpose. Our job was to make sure that USACE was asking the right questions during the investigation that would lead to concrete answers about the causes of the failure of the hurricane protection system. My team was focused on analyzing the risk and reliability of the water resource system in New Orleans, and we worked alongside the USACE team, starting with revising the investigation questions in order to get answers about why these water systems failed during the storm. Q: What was your experience like in New Orleans in the aftermath of the hurricane? Dr. Traver: My team went down to New Orleans a few weeks after the hurricane, visited all the sites we were reviewing and met with infrastructure experts along the way as progress was being made on the investigation. As we were flying overhead and looking at the devastated areas, seeing all the homes that were washed away, it was hard to believe that this level of destruction could happen in a city in the United States. As we started to realize the errors that were made and the things that went wrong leading up to the storm, it was heartbreaking to think about how lives could have been saved if the infrastructure in place had been treated as one system and undergone a critical review. Q: What were the findings of the ASCE and USACE investigation team? Dr. Traver: USACE focused on New Orleans because they wanted to figure out why the city’s levee system—a human-made barrier that protects land from flooding by holding back water—failed during the hurricane. The city manages pump stations that are designed to remove water after a rainfall event, but they were not well connected to the levee system and not built to handle major storms. So, one of the main reasons for the levee system failure was that the pump stations and levees were not treated as one system, which was one of the causes of the mass flooding we saw in New Orleans. Another issue we found was that the designers of the levee system never factored in a failsafe for what would happen if a bigger storm occurred and the levee overflowed. They had the right idea by building flood protection systems, but they didn’t think that a larger storm the size of Katrina could occur and never updated the design to bring in new meteorological knowledge on size of potential storms. Since then, the city has completely rebuilt the levees using these lessons learned. Q: What did researchers, scientists and the general population learn from Katrina? Dr. Traver: In areas that have had major hurricanes over the past 20 years, it’s easy to find what went wrong and fix it for the future, so we don’t necessarily worry as much about having a hurricane in the same place as we’ve had one before. What I worry about is if a hurricane hits a new town or city that has not experienced one and we have no idea what the potential frailties of the prevention systems there could be. Scientists and researchers also need to make high-risk areas for hurricane activity in the United States known for those who live there. People need to know what their risk is if they are in areas where there is increased risk of storms and flooding, and what they should do when a storm hits, especially now with the changes we are seeing in storm size.

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