Safety, Cost, and Environmental Impacts
Safety
Icy conditions can result in crashes and slip and fall injuries. Following physical removal of snow, the use of salt helps to regain bare pavement and safer conditions for driving and walking. States with harsh winters report three times as many emergency visits for falls on ice than states with milder weather. Tenants and visitors expect safe driveways, sidewalks, and other paved surfaces for daily travel and parking as well as access to mailboxes and deliveries.
Even with good winter maintenance practices, safe winter conditions require everyone to do their part by driving carefully, wearing appropriate footwear and clothing, and paying attention to walking surface conditions.
Cost
Economy
Road salt enhances winter safety, allowing businesses to stay open and our economy to keep moving — even in the harshest winters. Salt usage on roadways has reduced crash frequency by nearly 90%. With clear roads and parking lots, we can continue to drive to work, shop for groceries, and bring our children to school safely. The successful use of salt has created demand for immediate access to travel on roadways and to businesses and with that, greater demand for salt use.
Infrastructure Damage
Salt causes significant damage to property and infrastructure. Over time, it breaks down concrete surfaces, leading to cracks, spalling, and deterioration. It also speeds up corrosion of steel reinforcements and promotes rust on metal components. The impact is visible on curbs, sidewalks, railings, bridges, vehicles, and even inside buildings where salt is tracked onto carpets and entryways, damaging flooring. These effects not only reduce the lifespan of structures but also result in costly repairs and maintenance and unsightly appearance. The repair and replacement costs for damage to buildings, roads, bridges, vegetation, storm sewer systems, and vehicles is expensive. Applying one ton of salt results in estimated damages and repair costs of $1,700 to $17,000 (MPCA, 2023).
Approximately 400,000 tons of salt is applied on state-maintained roads each winter in Minnesota (Visit Annual Survey of State Winter Maintenance Data - Clear Roads to see how much salt is used on state-maintained roads by DOTs in your state). Estimates of salt use for parking lots and sidewalks range from about 7% to 25% and in some areas as much as 50% of total salt use. As a property manager or owner responsible for overseeing or funding repairs to your property from salt use both on the exterior and interior, salt damage can become costly.
Environment
Salt can pollute water, impair soil, harm plants and wildlife, and even pose health risks to people and pets. These impacts are long-lasting and expensive - affecting our homes, communities, and natural resources. Understanding these consequences is the first step toward smarter, more responsible winter maintenance.
Water
Surface water
Salt runoff enters lakes, rivers, wetlands, natural and stormwater ponds. Just one teaspoon of salt permanently pollutes five gallons of water to the national standard for protecting aquatic life from chloride. Water pollution from salt creates denser (heavier) water that sinks to the bottom of lakes and streams and may create layers that disrupt natural seasonal mixing and limit oxygen levels for plants, fish, and amphibians.
Salt runs off paved surfaces into storm drains or ditches that carry the salty water to our lakes, streams, or wetlands or to stormwater treatment ponds. These treatment ponds cannot remove the salt. Too much salt in stormwater treatment ponds can result in the ponds releasing phosphorus, the nutrient that causes excess algae growth in lakes, rather than retaining it as they are designed to do.
Groundwater
Salt infiltrates into groundwater, raising sodium and chloride levels. This can affect drinking water quality and mobilize other contaminants, creating long-term risks for human health. When salt dissolves and runs off with meltwater or washes off with rain, it enters lakes, streams, and groundwater. Over time, this raises sodium and chloride levels in drinking water. High sodium can be a concern for people with high blood pressure. Chloride, though not a human health risk, is regulated as a secondary contaminant for taste. Salt levels above 250 mg/L may result in salty tasting water. Salty water can also mobilize metals and other contaminants, creating a cocktail of pollutants that can pose risks to human and environmental health.
Soil and vegetation
Soils
When soil has excessive amounts of sodium it causes expansion of clay which reduces the infiltration of water. This results in soil compaction and poor conditions for plant growth which create conditions where salt-tolerant weeds and invasive species often take over. Maintenance crews may periodically have to replace soil along curbsides where salt concentrations have become high enough to limit growth of turfgrass or other vegetation.
Vegetation
Salt spray and runoff damage turfgrass, trees, shrubs, and other plants. Overapplication of salt burns vegetation and can kill trees and shrubs, leading to costly replacements. Salt-tolerant weeds and invasive species often replace native plants.
Wildlife and pets
Wildlife
Salt pollution disrupts aquatic habitats by reducing oxygen levels and stressing fish, amphibians, and other species. Elevated chloride concentrations can be toxic to freshwater organisms, and these changes ripple through the food chain — affecting insects, birds, and predators that depend on healthy aquatic ecosystems. Additionally, salt attracts wildlife to roadsides, increasing the risk of vehicle collisions and harm to both animals and people.
Pets
Building occupants may be concerned about products used on the property that could be harmful to their pets. Salt can irritate pet paws, causing dryness and cracks. Pets may lick salt from their paws or drink salty meltwater, which can be harmful. Most deicing salts are not pet-friendly, so less salt use is better.