\n\tLake Champlain Sea Grant and UVM Extension\u00a0partnered with the town of Hyde Park Highway Department to\u00a0offer a free training for municipal employees and others who\u00a0manage snow and ice on\u00a0roads\u00a0and other surfaces in winter.\u00a0The workshop\u00a0was\u00a0held at the Hyde Park Highway Department garage\u00a0on October 26.\u00a0In all, 67\u00a0people representing 19 different Vermont communities participated.\u00a0Using Hyde Park\u2019s snow and ice management\u00a0techniques\u00a0as an example, participants in the workshop learned about technologies that can help minimize use of road salt. These\u00a0practices\u00a0maintain public safety\u00a0and, while there is an initial\u00a0investment cost, they\u00a0can\u00a0ultimately\u00a0reduce\u00a0costs and benefit the environment.<\/p>\n
\n\tSince 2020,\u00a0with support of their select board,\u00a0Hyde Park staff, led by\u00a0Road\u00a0Foreman\u00a0Mark French,\u00a0have\u00a0taken steps to update their\u00a0road salting equipment\u00a0to\u00a0use\u00a0new\u00a0technologies. This has helped\u00a0them reduce road salt use by about 50 percent.\u00a0The technologies the\u00a0Hyde Park team\u00a0has\u00a0incorporated\u00a0include\u00a0purchasing equipment that allows them to\u00a0make\u00a0a salt-water mixture, called brine,\u00a0using the brine to\u00a0prewet dry\u00a0rock\u00a0salt before it is applied to the road, calibrating equipment\u00a0and measuring salt use during each storm, and using temperature sensors on their trucks.<\/p>\n
\n\tPrewetting salt\u00a0happens\u00a0\u201cat the spinner,\u201d\u00a0which\u00a0means the rock salt is wet with the 23.3 percent brine solution\u00a0on the truck just before the salt is spread onto the road. This\u00a0allows\u00a0the salt\u00a0to stick better to the road,\u00a0keeping it in place where it is needed to\u00a0prevent ice from forming on the road.\u00a0When the salt is not prewet, it tends to bounce off the road, requiring additional salt to\u00a0be added to\u00a0replace that which bounced off\u00a0the road.\u00a0Any salt\u00a0that bounces\u00a0or later washes\u00a0off\u00a0the road can in turn\u00a0damage\u00a0vegetation,\u00a0enter waterways where it can be toxic to fish and other aquatic life, and\u00a0cause changes in soil properties such as allowing\u00a0heavy metals\u00a0that come\u00a0from cars to move through the soil.<\/p>\n
\n\tMonitoring pavement temperatures with the on-truck sensors allows Mark and his colleague Ryan\u00a0Nolan,\u00a0to know when it makes sense to salt or not.\u00a0For instance, if they observe that pavement temperatures are 35F and the forecast calls for a sunny and warming day,\u00a0they know that ice won\u2019t form on that surface and can opt out of salting the road. On the other end of the\u00a0temperature scale, rock salt (which is sodium chloride) only works\u00a0down to pavement temperatures of about 15F.\u00a0So, if Mark or Ryan observe that pavement temperatures are lower than that, they can save salt by not spreading it as it won\u2019t be able to keep ice from forming at such temperatures.\u00a0<\/p>\n
\n\tMark shared that \u201csalt is immediately activated by the salt brine,\u201d so its beneficial work of keeping roads ice free starts to happen right away\u00a0when pre-wet salt is spread. When dry rock salt is spread\u00a0on roads or other surfaces, it must mix first with water to begin to lower the freezing point of water\u00a0and keep those surfaces ice-free.\u00a0As water molecules try to bond with one another to form ice,\u00a0sodium\u00a0and chloride\u00a0(which break apart into separate molecules when in water)\u00a0get in between the water molecules. This\u00a0process\u00a0keeps\u00a0ice from forming.\u00a0When\u00a0pavement temperatures are below\u00a015F,\u00a0there isn\u2019t water available in liquid form to mix with the\u00a0sodium chloride, explaining why\u00a0salt\u00a0doesn\u2019t work\u00a0to keep surfaces ice-free\u00a0at lower temperatures.<\/p>\n
\n\tFinally, calibrating equipment is\u00a0important, as it allows\u00a0Mark and Ryan\u00a0to track how much salt is going out\u00a0at any moment in time. Their goal is to only put out what\u2019s needed to keep ice from forming on the road, so if they know how much is going out at any given setting\u00a0on their controls, they can be sure to put enough out to keep roads safe, but not too much.<\/p>\n
\n\tThe practices that Hyde Park implements are not the only ones that can help reduce the use of salt. For instance, South Burlington uses plows with multiple rubberized segments. The individual segments can do a better job scraping snow and ice off of surfaces to\u00a0prepare them to add salt. They also have secondary plows on some trucks, which also help to clean the surface.\u00a0No matter if it\u2019s professionals adding salt or individuals at their homes, the idea is that salt should only be added to clean surfaces, not to snowy or icy ones, as it can do its job to prevent ice formation on surfaces\u00a0only when in contact with those surfaces.\u00a0<\/p>\n
\n\tMark also shared that, \u201cwhoever is spreading salt needs to be educated in salt use.\u201d\u00a0It is important that snow fighters understand how salt works\u00a0to keep surfaces free from ice. This includes understanding the\u00a0temperatures at which\u00a0sodium chloride\u00a0works, what happens to dry or prewet salt when it hits the pavement\u00a0and how that\u00a0can be affected by traffic or other road conditions, and\u00a0having awareness of what happens in the environment\u00a0when salt finds its way into waterways, soils, and vegetation.<\/p>\n
\n\tAs users of roadways,\u00a0residents in communities throughout the Lake Champlain basin and beyond\u00a0can help snow fighters do their jobs\u00a0by supporting budgets\u00a0that keep road and sidewalk surfaces in good shape and\u00a0that allow\u00a0municipalities to invest in new\u00a0snow and ice management\u00a0technologies, both of which\u00a0can\u00a0help them to\u00a0reduce their use of salt.\u00a0<\/p>\n