Winter road salt is a threat to Philly’s spring season, so officials are searching for alternatives that cause less harm

Treating snowy and icy roads has a year-round environmental impact, experts say.

A mini water spout in East Fairmount Park

A mini water spout in East Fairmount Park

Mark Henninger / Imagic Digital
ashaprihar-headshot

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Springtime is on its way (fingers crossed).

It was sunny and 50-something degrees when the City Council’s Streets and Services Committee convened last Thursday. The topic was of a colder tone: road salt.

Philly’s stuck right now in what some would call the “spring of deception” — a cycle of beautiful, warmer days interspersed with waves of freeze, and sometimes even wintry precipitation (see last weekend). When can the city safely tuck away the snow plows and brine trucks? Who’s to say, really.

One thing that’s certain: Philadelphia, its waterways, its plants, and its wildlife feel the effects of winter salt usage across the region well into spring, summer, and fall, according to environmental experts and advocates who testified at the hearing.

“This is all year long,” said Laura Toran, a Temple professor who specializes in urban hydrology. “It’s not just in the winter.”

The timing of the hearing will allow the city to get a head start on figuring out what changes might be made before next year, said Councilmember Isaiah Thomas, who chairs the committee and introduced the resolution to hold the “Beets, Brine, and Salt” hearing.

“If we’re going to try to bring about any change in how we address this issue, we recognize that it’s going to take time to implement that change,” Thomas told Billy Penn.

Bad for drinking water, bad for butterflies

The traditional treatment for keeping roads and sidewalks clear of icy conditions has for years been contributing to a dangerous salt increase in the city’s water supply, said the experts at the City Council hearing.

Whether in scattered chunks or sprayed brine, road salt doesn’t just disappear into thin air after it helps to melt the snow and ice. It ultimately ends up in local bodies of water.

The issue is worse now than ever, according to John K. Jackson, a senior research scientist at the Stroud Water Research Center in Avondale. In the Philadelphia area, he said, salt concentrations in streams have been observed to be 10 or 100 times higher than in the 1940s. It’s an issue in many parts of the country that deal with changing seasons.

“Increased salt in our waterways is not just a Southeast Pennsylvania region problem,” Jackson said. “It really extends from North Dakota all the way down to Virginia. And it’s really tied to the use of road salt primarily, and especially in this area.”

Compared to a normal salt concentration below 10 or 20 mg per liter, urban hydrology prof Toran has seen levels averaging around 200 mg in Wissahickon Creek and Cobbs Creek. High all year round, salinity levels reach their highest in the winter, she said — over 1,000 mg per liter, in some cases.

By comparison, at Fort Indiantown Gap — a military base in central Pennsylvania where salting the roads isn’t usually necessary because people drive around in humvees — concentrations are below 50 mg per liter and have only risen 5 or 10 mg since the ’70s.

Since it’s located downstream on bodies of water like the Schuylkill or Wissahickon, Philly also catches the effects of salt application in the suburbs, some of which are applying more salt than others, Toran noted.

Road salt covers a Center City parking lot in March 2022 after threat of a minor storm

Road salt covers a Center City parking lot in March 2022 after threat of a minor storm

Danya Henninger / Billy Penn

Since the Philadelphia Water Department isn’t able to remove salt, increased levels can have a direct impact on the drinking water supply, said Geoffrey Selling, a retired science teacher and a volunteer chloride monitor with the Izaak Walton League’s Winter Salt Watch Program. About 42% of the city’s drinking water supply is drawn from the Schuylkill, and the other 58% comes from the Delaware.

Saltier drinking water poses health risks to people who need to limit their salt intake, Selling said. It can also cause corrosion in pipes, noted Stephanie Wein — a clean water advocate at the environmental advocacy organization PennEnvironment — which could lead to more instances of lead contamination.

The salinity is also bad for freshwater animals accustomed to living in low-salt environments. But salt doesn’t only impact water — it can stick around in the soil well into the spring.

“[The salt is] stored in the soil as it travels on its way to the stream,” Toran said. “And we don’t see enough freshwater clearing out that salt water in spring and summer.”

A salt concentration that’s too high can stop certain plants from growing, Wein said. And while some plants can survive, she added, they’ll have more salt content within them, which in turn can become an issue for animals who live off those plants.

One example? Butterflies.

Monarch butterflies live off milkweed plants, Wein pointed out. Researchers at the University of Minnesota have found that while a certain level of salt can be good for muscle growth and eye size in the creatures, too much can be poisonous.

A pitch for education over ‘Beet Heet’

The Streets Department has made improvements over the last 10 years to be more mindful of the environment while still making sure the roads are safe, said Deputy Commissioner Richard Montanez at the hearing.

“For years, the philosophy was more salt is better,” Montanez said. “The city has a capacity to stock over 50,000 tons of salt, but that does not mean that we use it.”

Workers no longer spread dry salt before precipitation begins, instead waiting until the snow begins to fall, for example. The department has also increased brining efforts, applying the mixture of salt and water 48 to 72 hours before an expected winter storm, unless there’s rain in the forecast first. The city mainly uses it on “higher level streets and primary roadways,” Montanez said.

Pennsylvania’s Department of Transportation is also brine-forward these days, according to PennDOT Senior Assistant District Executive John Krafcykz. The agency sprays a 23% salt solution onto highways before storms, adjusting the amount based on temperature.

The agency has also begun pre-brining the rock salt spread while storms are ongoing, which Krafcykz said makes for quicker melting and allows for 20% to 30% lower salt usage overall.

Both Krafcykz and Montanez from the Philly Streets Department said they’d considered using beet juice-based additives, but ultimately decided against it, citing high cost and concerns over smell and water quality.

Unsurprisingly, makers of a product called “Beet Heet” disagree. Denver Preston, national sales manager at the Indiana-based company K-Tech Specialty Coatings, made a pitch at the hearing for the sugar beet-based additive that he said could be mixed with brine to improve melting capability. The higher cost of the product is balanced out by its performance and the need for less of it, Preston argued.

“There’s really no easy solution,” said Jackson, of the Stroud Water Research Center. “We have to reduce the salt.”

Many panelists underscored that it’s not just the city that needs to address the problem — homeowners and businesses use a lot of salt, too. They suggested the city channel efforts into educating people on the issue and communicating with upstream counties.

Jackson noted that New Hampshire runs a certification program for private road salt applicators that trains them to spread salt more efficiently.

“I think cities can be the people that look for those solutions, and then teach the businesses and the public what they can do better,” said Toran, the Temple urban hydrology professor. “So we can be a real role model if we can figure this out.”

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