Road salt primarily gets into water sources through runoff, snowmelt, and direct application during de-icing processes.
Here's a breakdown of the ways road salt contaminates water sources:
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Runoff: When road salt is applied to roads and highways, rain or melting snow washes it away, carrying it into nearby bodies of water such as streams, rivers, and lakes. This is a significant source of contamination, especially during and after snowstorms.
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Snowmelt: Plowed snow often contains high concentrations of road salt. When this snow melts, the resulting water flows into drainage systems, ditches, and eventually into surface water and groundwater sources.
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Direct Spraying: Some de-icing methods involve spraying a brine solution (a mixture of salt and water) directly onto roadways. This can lead to overspray that reaches roadside ditches and banks, eventually seeping into the ground and affecting both surface and groundwater.
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Infiltration into Soil and Groundwater: Salt that is washed onto yards, roadside vegetation, or directly onto the ground can infiltrate the soil. Over time, this salt can leach into the groundwater, contaminating aquifers and wells. The following contribute to this process:
- Plowing: Moving contaminated snow away from roadways increases the likelihood of infiltration into the surrounding ground.
- Meltwater: Melted snow permeates the soil, transporting salt with it into the ground.
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Storage and Handling: Improper storage of road salt can also contribute to water contamination. If salt piles are not covered or properly contained, rainwater can dissolve the salt and carry it into nearby water sources.
Road salt contamination can have serious consequences for aquatic ecosystems, drinking water supplies, and infrastructure. It's vital to implement responsible road salt management practices to mitigate these impacts.
