Madelyn Garcia, Watershed Specialist

As autumn fades and winter approaches, road crews across Pennsylvania start gearing up with plows and salt spreaders. While road salt keeps our roads safe in icy conditions, it can have lasting consequences for the health of our local streams, lakes, and groundwater. But did you know that the type of winter weather we get — rain or snow — actually changes how road salt moves through the environment? 

 

The Science Behind Road Salt 

Contrary to popular belief, salt doesn’t actually melt snow or ice. Instead, it helps prevent ice crystals from forming in the first place. Salt, in this case, refers to sodium chloride (NaCl)—the same compound found in table salt. When it mixes with water, it breaks apart into charged particles called ions. These sodium (Na⁺) and chloride (Cl⁻) ions interfere with how water molecules bond, lowering the temperature at which water freezes. 

When we walk or drive on salted surfaces, the pressure helps crush the salt so it can dissolve faster and start working. That is why salt is so commonly used in winter: it is simple, affordable, and effective for keeping roads and sidewalks safer. 

However, salt only works well within a certain temperature range. Once it gets colder than about 15°F, regular road salt becomes much less effective. To help with this, PennDOT and local road crews often pre-wet salt with a brine solution before spreading it. The brine helps salt stick to the pavement and start reacting more quickly while reducing waste and runoff. 

The problem is that once salt dissolves, it does not disappear when the snow melts. Those same sodium and chloride particles move into nearby soil and water, where they can remain long after the storm is over. 

 

 

How Salt Moves Through the Environment 

So now that we know what salt does on our roads, what happens once it washes away? The answer depends a lot on the kind of winter weather we get. 

When precipitation falls as rain, salt dissolves right away. Rain acts like a solvent, washing the salt off roadways and into storm drains, ditches, and streams. This quick flush can cause sudden spikes in salt concentration, which may stress or even kill sensitive fish, amphibians, and aquatic insects. When precipitation falls as snow or ice, salt often gets trapped in the snowpack and releases slowly during thaw cycles and spring melt. A snowpack is the layer of snow that builds up on the ground over the course of the winter. It acts like a sponge, soaking up not just snow and ice but also pollutants like road salt. As temperatures rise, the snowpack melts gradually, releasing that salt into nearby soils, streams, and groundwater. This steady trickle raises salt levels in both groundwater and surface water over time. The result is a long-term process known as freshwater salinization.  

Salt does a great job keeping us safe on slick winter roads, but it doesn’t just vanish with the last snowflake. The chloride in road salt — our cold-weather hero — is also a bit of a troublemaker. Once it’s out in the environment, it sticks around for good as a permanent pollutant, causing problems long after winter has packed up and left. Plants can’t soak it up or filter it out, so that salt ends up right where we don’t want it. As it’s scattered across roads, sidewalks, and parking lots, it splashes onto nearby soil and vegetation. 

 The result? Crispy grass, struggling shrubs, and bare patches of dirt that are more likely to erode. And it’s not just nature that takes a hit.  It eats away at bridges, rusts our vehicles, and breaks down concrete, leading to expensive repairs and a shorter life for our infrastructure. 

 

 

Smarter Salting for a Healthier Winter 

Here in Pike County, where clean water and healthy landscapes define our community, both pollution patterns matter. Rain can send a rush of salt into our streams, while snowmelt keeps feeding salt into the environment long after winter ends.  

It might sound like a big issue, but the good news is that small changes really do make a difference. By using salt wisely, each of us can help protect our local streams, lakes, and wells this winter — and even save a little money and wear-and-tear in the process. 

Before and during storms, try these smart salting tips: 

• Shovel first. Clear as much snow and ice as you can before salting. 

• Use the right amount. A coffee mug’s worth (about 12 ounces) is enough for a standard driveway. 

• Check the temperature. Below 15°F, salt will not melt effectively. Use sand or kitty litter for traction instead. 

• Sweep up leftover salt once surfaces are clear, so it does not wash into drains. 

• Store salt in a covered, waterproof container. 

• Keep salt at least 5 to 10 feet away from streams, drains, and plants.
   

Looking for safer alternatives? Try these: 

• Calcium magnesium acetate (CMA): Effective and less harmful to plants and waterways. 

• Magnesium chloride: Works well at lower temperatures and is gentler on vegetation. 

• Sand or grit: Adds traction without adding chemicals. 

• Pickle brine or saltwater mixtures: Help prevent ice from bonding to pavement but should be used sparingly.
   

By following these simple steps, we can all help reduce salt pollution, protect water quality, and extend the life of our driveways, vehicles, and infrastructure. 

 

The Pike County Conservation District is proud to partner with the Salt Watch Program, hosted by the Izaak Walton League of America. Salt Watch raises awareness about the link between road salt and public health, helps identify waterways with high salt levels, and promotes smarter salting practices by sharing results with landowners and local agencies. 

Residents can join this effort by requesting a free Salt Watch kit directly from the Izaak Walton League of America to test local water and track chloride levels throughout the winter. It is a simple, hands-on way to make a real difference for our community’s clean water. Click here to learn more. 

For more tips and information, visit: 

• Guide to Salt Management for Homeowners (Carroll County, MD)

• Reducing Use of Deicing Salt (University of Vermont Sea Grant)

• PennDOT Winter Tools and Terms