Road Salts and Deicers: How to Safely Salt for Humans and Wildlife

When winter weather hits, road salt feels like a small miracle. A quick sprinkle on sidewalks and driveways can turn dangerous ice into safer footing, and for many of us, salting our driveways and sidewalks is simply part of winter routine.

But long after winter storms pass, that salt persists and does harm to harm wildlife, water, and even our gardens. Once the ice melts, salts wash into nearby soil, storm drains, streams, and lakes, where it can linger for years. The good news? Keeping people safe in winter doesn’t have to come at nature’s expense!

Use calcium and magnesium chloride-based deicers rather than rock salt (sodium chloride). In warmer temperatures, consider using acetate-based or glycol/urea-based deicers to avoid salt altogether.

Why Road Salts Don’t Stay on Roads

Each winter, up to a 32 million tons of salt are spread across roads, sidewalks, and parking lots in the U.S.—more than the total biomass of land mammals on Earth—to melt ice. And because salt dissolves easily, it moves wherever water flows. Meltwater carries it into storm drains, roadside soils, groundwater, and nearby streams and lakes.

Salt doesn’t break down over time; it can persist in soil and groundwater for decades, slowly seeping into waterways year-round. As a result, some urban streams now reach salt levels comparable to seawater after winter storms!

Impact of Road Salts on Plants and Habitat

Traditional road salt (sodium chloride) degrades the habitats animals rely on. When salt dissolves, sodium and chloride ions move into nearby soils, lawns, and garden beds. Too much sodium destroys soil structure and forms dense, crusted, or even impenetrable layers by replacing essential soil nutrients like calcium and potassium. Meanwhile, chloride interferes with photosynthesis and causes the familiar browning known as “salt burn.”

Over-salted water can also be disastrous for freshwater habitats by causing toxic algae blooms. When salt levels rise, they can quietly reshape how lakes function. Extra chloride changes how water layers stack and mix, slowing the natural circulation that helps move nutrients through the lake. As a result, nutrients become trapped near the surface where harmful algae can consume it and proliferate, smothering the ecosystem below.

How Road Salts Harm Wildlife

Freshwater ecosystems are not built to handle salt. Fish, amphibians, freshwater mussels, and aquatic insects evolved in low-salt environments, and even small increases in chloride can interfere with a freshwater species’ ability to regulate fluids, breathe, and grow.

Amphibians face particular risks: frogs and salamanders absorb water directly through their skin, making them highly sensitive to salt pollution. Studies have linked road salt to developmental stress, bloating, deformities, and increased disease severityin tadpoles living near treated roads.

On land, salt creates its own dangers. Deer and other mammals are drawn to salty roadsides, which increases the risk of vehicle collisions. Birds may also ingest salt, mistaking it for grit. Moreover, salt can irritate the paws of our pets and is toxic if too much is ingested.

Which Deicers are Safest for Wildlife?

Not all deicers work the same way, or have the same environmental impact. Some don’t even require salt! The type of product used, how much is applied, and when it’s used can all make a big difference for nearby wildlife and waterways.

Traditional rock salt (sodium chloride) is the most familiar option, but it’s also the largest contributor to freshwater salinization. If salting is necessary for safety, it’s recommend using calcium and magnesium chloride-based deicers instead of sodium chloride. These other salts can work at lower temperatures, reduce the total amount of chloride needed, and don’t harm soil structure the way regular rock salt does.

Better yet, there are non-salt option that don’t cause any of these problems, such as calcium magnesium acetate (CMA) and glycol/urea-based deicers. However, these can be expensive and are usually limited to warmer freezing temperatures.

Any deicer comes with tradeoffs; even non-melting options like sand avoid chemical pollution but can create sediment problems if overused! Check out our cheat sheet below to compare common deicers types and when they might be most appropriately used. Before choosing a deicer brand, be sure to see what chemicals are in the mix!

Smart Salting Practices That Protect Wildlife

Protecting wildlife in winter starts with using less salt overall. Many icy surfaces can be managed safely with thoughtful timing and targeted action.

 Avoid Salt Completely

• Shovel early and often: Removing snow before it gets packed into ice can eliminate the need for salt entirely.
• Use Traction Options: Use rough particles such as sand, gravel or kitty litter to create traction on ice instead of melting it—just be sure to clean it up!
• Use Non-salt Options: At more moderate cold temperatures, use calcium-magnesium chloride acetate (CMA) or glycol/urea-based deicers to melt ice without worrying about the effects of salt.

Reduce the Amount of Salt Used

• Less is more: About one coffee mug of salt (roughly one cup) can treat ~250 square feet.
• Target trouble spots: Focus only on steps, slopes, and shaded areas instead of salting entire surfaces.

Plan Ahead

• Watch temperatures: Don’t salt below effective ranges (~15 °F for sodium chloride, ~-25 °F for magnesium and calcium chloride). CMA is not effective below 20 °F. Use traction options if temperatures drop below -30 °F.
• Anti-ice with a brine solution: Apply liquid brine before storms to prevent ice from bonding to pavement. You can make brine by dissolving calcium or magnesium chloride salt in warm water (about 1 pound of salt per gallon of water makes ~20% brine). Fill a garden sprayer or watering can and pre-treat target areas before a storm. This can cut salt use by up to 75%.

 Protect Gardens and Plantlife

• Keep Salt Away from Roots: Create buffers and avoid piling salted snow onto plants. Be cautious in late winter when buds emerge.
• Wash It Out: Rinse salt spray from shrubs when temperatures allow. Flush soils in spring and restore nutrients with compost. Remove any sediment used for traction.
• Plant Smart: Choose salt-tolerant plants near road or pathway edges.

Safer Winters, Healthier Ecosystems

Winter safety and wildlife protection don’t have to be at odds. By using deicers more thoughtfully (and only when they’re truly needed) we can reduce salt pollution while still keeping sidewalks, driveways, and roads safe for people and pets.

Small changes, like shoveling earlier, applying less salt, or choosing smarter alternatives, add up across neighborhoods and communities. When we treat winter storms with care, we protect not just our footing, but the streams, soils, plants, and wildlife that surround us long after the snow has melted.