Winter Tips for Salt & Stormdrains
|Snow and ice removal is a balancing act between safety and cost. When freezing weather hits, sidewalks and driveways can become dangerously slick. Salt has been used on roadways for snow and ice removal since the 1930’s and remains the most cost-effective de-icer. However, without proper use, it can easily be transported by melting water to groundwater or stormdrains. Because rain and snowmelt are moved through stormdrains straight to rivers and streams without treatment, chloride ions are often delivered to receiving streams in concentrations that can harm aquatic wildlife. Even runoff that is directed to vegetated areas is not safe for surface waters. The chloride ion remains in ground water as it moves through the soil profile and can contaminate streams months later when the stream receives ground water as base flow. |
So what are the alternatives for safety, cost, and environmental sustainability? Alternative chemicals include magnesium chloride, potassium acetate, calcium chloride, calcium magnesium acetate, potassium chloride, and agricultural by-products (ABP) but alternative de-icing chemicals can also have environmental drawbacks, so it becomes a matter of doing less harm rather than no harm.
Knowing that doing nothing is just not possible, we find ourselves asking, what can be done to at least minimize runoff concerns?
-One consideration often overlooked is the design of parking lots and sidewalks. Pervious paving systems have been shown over the last decade to withstand the rigors of northern winters and to reduce the need for de-icers. During the day when snow melts from sunshine, the water moves through the paving material leaving a drier sidewalk that won’t re-freeze when the sun sets.
-Another option to reduce the risk of de-icing chemicals is implementing the correct storage. Leaving an uncovered pile of salt in the corner of a parking lot or storage area allows melt water to carry dissolved salt to the nearest storm drain inlet. This practice can also lead to a citation for illicit discharge to a storm sewer system.
-Anti-icing or pretreatment has been shown to reduce the amount of de-icing chemicals used. Applied before a snowfall, pretreatment prevents bonding between snow and paving, and makes snow removal quicker and easier.
-Most importantly-proper usage! Use the minimum amount of deicer or anti-icer. It’s only supposed to break the bond to make shoveling easier.
Read more opinions on salt application from various central Ohio professionals in this Columbus Dispatch article.