Remember that today’s snow is tomorrow’s river and lake. Here is my annual list of how to limit the stormwater pollution you create during the winter.
Shovel early and often. When it comes to snow removal, there is no substitute for muscle and elbow grease! Deicers work best when only a thin layer of snow or ice must be melted. So move as much snow as you can during the storm if possible. You can also use a hoe to scrape ice off the surface before putting down a deicer.
There are times when shoveling isn't enough. Salt and sand have traditionally been perceived as the cheapest and most effective materials for deicing surfaces such as highways, walkways and parking lots. However, many of these products have hidden impacts.
When the ice melts, the salt and chemicals dissolve and flow into street drains that lead directly to a lake or stream. Depending on the product used, these impacts can range from reducing oxygen levels in our lakes and streams to “burning” or killing vegetation along sidewalks and roadsides, to damaging concrete and carpets, to increasing sediment and phosphorus levels and introducing toxic chemicals such as cyanide, chlorine or ammonia in our lakes and streams.
Be smart about salt use. The most important step in deicing is to physically remove as much snow and ice as possible before applying salt. Use a shovel to break up the ice before you add another layer of salt to your sidewalk.
You can also reduce salt use by limiting access to your home to one entrance.
A little goes a long way. By limiting the amount of salt we use on sidewalks and driveways, we can reduce the amount of polluted stormwater washing into our waterways.
The recommended application rate for rock salt is about a handful per square yard treated (after you have scraped as much ice and snow as you can). Throwing any more salt down won’t speed up the melting process.
Even less salt is needed if you are using calcium chloride (about a handful for every three square yards treated). Use only enough deicer to break the ice/pavement bond, then remove the remaining slush by shoveling.
Avoid fertilizers and products with urea. Some folks recommend the use of fertilizers including those with urea (carbamide, ammonium, carbonyl diamide, etc.) because they don’t contain chlorides and, since they contain nutrients (urea is a form of nitrogen) which will help plant growth when the snow and ice melts. In reality, urea-based deicing products can be expensive and perform poorly below 20 degrees F.
Potassium chloride (Potash) is also a fertilizer used to combat snow and ice. Potassium chloride typically costs three to five times as much as sodium chloride and doesn't work as well.
The bottom line to dealing with ice and snow this winter in a way that protects our waterways is to shovel early and often, reduce the amount of deicer you use and be very contentious in how you apply deicing products.