Posted by Angie Hong | Posted in Keeping water clean | Posted on 06-01-2014
Remember standing, waiting for the school bus in the morning with your winter coat unzipped, gloveless hands in pockets, and, certainly, no hat on your head because that would mess up your hair? Buying my first pair of adult-sized snow pants and mukluks, two years after college, was a transformative experience. The world outside was suddenly a playground with animal tracks to follow, snowy hills to climb, and frozen ponds to cross. Adapting for the winter made everything so much better.
A growing number of lakes and streams in the Twin Cities metro area have become too salty for fish and other aquatic life to survive due to the large amounts of salt and deicers we’re applying to roads, parking lots and sidewalks during the winter. Furthermore, a Minnesota Pollution Control Agency (MPCA) report released earlier this year revealed that 30% of private wells in the metro area have chloride concentrations greater than the chronic water-quality standard set by the US Environmental Protection Agency. Are we adapting to the winter or trying to make winter adapt to us?
As little as a single teaspoon of salt pollutes five gallons of water, the equivalent of a 50 lb. bag of salt polluting 10,000 gallons of water. Salt washes off of pavement into storm sewers that connect to lakes and streams, and once it is there, the dissolved chloride becomes toxic to aquatic plants and animals. In streams, chloride concentrations tend to peak in the mid-winter when we are using the most salt on roads and parking lots. For example, water quality data from Battle Creek between 2002 and 2007 shows that chloride levels spike every year around January and February. Of the 142 metro area lakes monitored for chloride by the Minnesota Pollution Control Agency (MPCA), Metropolitan Council and local Watershed Management Organizations (only a fraction of the 949 lakes in the metro), 28 have too much chloride and about a dozen more are headed in that direction. East metro area lakes and streams with unhealthy levels of chloride include Silver Lake in North St. Paul, Tanners Lake in Oakdale, Carver Lake in Woodbury, Battle Creek and the Sunrise River. In addition, Battle Creek Lake in Woodbury and Beaver Lake in Maplewood / St. Paul are at high risk for exceeding the water quality standard in the next few years.
In response to this problem, many local municipalities have educated their staff, changed their practices, and purchased new equipment to reduce salt use while still maintaining safe roads. Nonetheless, many communities and private contractors continue to apply more salt than necessary, even when they know it won’t help, because they fear complaints from the public. It seems that we all need to do a better job of adapting for the winter if we want to protect our precious water resources. With this challenge in mind, I offer some lessons I’ve learned since my stubborn teenage days.
First of all, it is better to don a snow boot than to curse the snowy sidewalk. In fact, many people I know wear snow boots to work and then leave them near the doorway and change into different shoes when they arrive. Wearing Yaktrax or a similar strap-on traction device over your shoes also makes it much easier to walk (or even run) on city sidewalks or icy trails without slipping and falling. On that note, I’ve determined that the easiest and most enjoyable way to walk around town with my two-year old during the winter is to pull him behind me in a sled rather than struggling to push a stroller in the snow or carrying him precariously on my back. Ironically, this often causes me to curse the few people who’ve actually cleared their sidewalks down to the pavement.
Second, though I rarely follow this advice myself, shoveling early really is the most effective way to clear your driveway and sidewalk before the snow becomes compacted. Throwing salt on top of snow just creates a slushy slippery mixture that still needs to be shoveled, and salt stops working completely when the pavement gets too cold (sodium chloride stops working around 15°, while magnesium and calcium chloride can go down to 0°). If you do use salt, use no more than 4lb of deicer for 1000 sq ft; one heaping coffee cup of salt weighs about one pound and can melt ice on an area about the size of a two car parking space. On a warm melting day, no salt is necessary and, when the weather is really cold, the best option is to use sand, which doesn’t melt the snow but provides traction and can be swept up and reused afterwards.
Finally, when it comes to driving, go slow, leave early and be glad that winter in Minnesota doesn’t last forever. Better yet, use your extra time in the car to daydream about all the fun things you’ll do on healthy, freshwater lakes when summer finally returns.
Head to www.mnwcd.org to watch a 15-min video with tips for maintaining your driveway and sidewalk during the winter or to download a list of winter maintenance companies certified by the MPCA.