Road salt is traditionally used to treat roadways before winter weather approaches. It keeps the roadways from getting too slippery and creates a slightly safer commute.
After the winter weather is over, where does the salt go? Does it get absorbed into the roadways or tranported somewhere else?
Joel Snodgrass, department head of Virginia Tech’s Department of Fish and Wildlife Conservation, and his research team conducted a study on road salt contamination in stormwater ponds. It is common for road salt to runoff into drains and sewers after precipitation washes it off the streets. While other pollutants, such as litter, could be easily taken out of the pond, the compounds from road salt lingered heavily.
These huge plumes of road salt in the stormwater ponds would contaminate groundwater, which in turn would run into streams and lakes.
Groundwater in urban areas average 100-150 milligrams per liter of chloride. When road salt is factored in the totals get higher.
“When it rains on the road salt, the amount of chloride can reach 1,000 milligrams per liter. These values threaten aquatic life.”
Snodgrass compared the high amounts of chloride to saltwater for freshwater fish; it’s hard from them to survive in these environments plagued by large amounts of road salt materials. It not only harms aquatic life, but can also impact humans. Road salt contaminates can also leak into well water.
“It can cause problems if you have high blood pressure, and can cause problems if you’re on a low sodium diet,” Snodgrass said.
Not only does it affect health, but also household appliances such as hot water heaters and dishwashers. The salt can corrode these appliances at a faster rate.
The effects of road salt contaminating well water would be costly since residents would have to drill a new well to rid themselves of the issue.
Snodgrass says this is a problem that many people don’t notice or think about right away.
“I don’t think people see it” Snodgrass said. “We see trash, so when you talk about littering and you see soda cans laying around and those kinds of things, that’s very obvious to us and we pick up on it. But really, for most of us, the salt is out of sight.”