It’s difficult to imagine a day like today in Boston without the aid of salt to make our roads safe to use. For those of us in the snowier parts of the country, road salt is a necessary and accepted part of our winter. It’s cheap, effective and it allows commuters, motorists and emergency vehicles to safely reach their destinations in harsh conditions. According to the Salt Institute, Americans used 22 million tons of road salt in 2008. In a different study by the National Research Council, Massachusetts tops the list of of states with the highest road salt-use at, 19.94 tons per lane-mile each year, surpassing even New York, with 16.6 tons per lane-mile. Under MassDOT salt policy, salt or sodium chloride is applied at 240 pounds per lane-mile. In other words, trucks in Massachusetts are dumping more than a ton of salt every 10 lane-miles in a single application! Salt does not evaporate or otherwise get removed, so one has to ask: what is the fate of all this salt that is dumped on our roads?
Unfortunately, most of it is washed off of roadways by rain runoff and snow melt and enters our rivers and streams or percolates through the soil into our drinking water supplies. That’s the situation that Cambridge, MA has been combating for years. This densely-populated city gets its water from two reservoirs, both located next to Route 128, making it particularly susceptible to salt contamination. Another town suffering from the same issue is Boxford, MA. The town launched a suit against the state highway department, MassHighway, to close its salt storage shed, contending that it was responsible for contaminating at least 30 local wells. Aside from the ecological damage of excess salt, there are also health and financial burdens associated with high salt levels in public and private water supplies. High salt levels can result in skin and eye irritation and pose a danger for individuals with sodium-restricted diets, according to the New England Interstate Water Pollution Control Commission.
MassHighway is already under court order to manage stormwater runoff after CLF’s successful suit in 2008. Hopefully this effort will divert some of the salt from our waters and, in turn, lead to better health for both the environment and the MA residents who live in it.