Ten years ago, the Freshwater Society invited environmental organizations, companies that produce winter road de-icing salts and
|Anti-icing products reduce chances ice will form|
chemicals, scientists, policy-makers and transportation workers to the first Road Salt Symposium.
The conference, titled “Bringing Salt to the Table,” was planned to increase awareness of an often overlooked pollutant. Road salt was damaging Minnesota’s waters, and it was time to share that knowledge so changes could be made.
More than 125 city, county and state transportation workers attended that first symposium on an icy January day. Many of them plowed roads early so they could attend. It was clear that the people who clear the roads and apply the salt were aware of its impacts on ecosystems and interested in improving their practices.
On Thursday, Feb. 3, the Freshwater Society will sponsor the 10th annual Road Salt Symposium at the Minnesota Landscape Arboretum. For information, go to www.freshwater.org or call 952-314-8133.
The problem with road salt
More than 22 million tons of road salts are applied to U.S. highways, streets, and sidewalks to make them safer for winter driving and walking. The most common deicing salt is sodium chloride. It is readily available, inexpensive and effective. Eventually, though, that salt drains off pavement and washes into lakes, rivers and wetlands.
Some of it makes its way into groundwater, the source of drinking water for most Minnesotans.
Five Twin Cities streams are listed as polluted by the Minnesota Pollution Control Agency because of high chloride levels. They are: Minnehaha Creek, Nine Mile Creek, Bass Creek, Bevens Creek and Shingle Creek. The chloride can change water chemistry enough to affect food chains, killing aquatic plants and animals.
Salt also kills plant roots and burns foliage in vegetation up to 200 feet from roads. Salt builds up in soil. Often, when native vegetation is killed, more salt-tolerant invasive species replace it.
Road salt also causes damage to roads, bridges and other infrastructure. The U.S. Environmental Protection Agency estimates the cost at $22.6 billion per year.
Ten years of providing solutions
Since its beginning, the Road Salt Symposium has featured local, national and international experts presenting information on keeping
|Salt pile next to a wetland illustrates a bad practice|
winter roads safe while mitigating road salt’s effects on water. The symposium has highlighted best management practices for removing snow and ice, and chemical and non-chemical alternatives to salt.
Kathleen Schaefer, formerly of the Minnesota Department of Transportation and currently a trainer for the University of Minnesota’s Local Technical Assistance Program has sounded a consistent theme in the conferences: Use the right material, at the right time, in the right place and keep it there long enough to do the job.
Many of the innovative practices featured at the symposium have become standard procedure for transportation departments. “Transportation departments are tasked with fixing problems in many situations,” said Connie Fortin of Fortin Consulting. “They understand road salt’s impact on water quality and they challenge themselves to make changes.”
Fortin Consulting, the Minnesota Pollution Control Agency and the university’s Local Technical Assistance Program are sponsors with the Freshwater Society of the 2011 symposium.
One of the significant changes in snow and ice removal over the last 10 years has been a major decrease in the use of sand, which often is ineffective and adds sediment to surface waters.
Another important change has been in the way road salt is applied. Many public agencies and private contractors now pre-wet the salt or use salt brine or another additive. This enables the salt to stick to the road and can help melt ice at lower temperatures.
In addition to promoting wise use of salt, the Road Salt Symposium has explored alternative chemicals as replacements for salt or as salt additives. Non-chemical alternatives, such as snow fences, also have been discussed and promoted at the symposiums.
Presentations at the 2011 symposium will again offer innovative solutions to the harmful impacts of road salt use. A trade show will also highlight products and equipment available to reduce road salt pollution.