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~„ Coutin>red from page 3 water. Nevertheless, Stefan said he worries more about long-term chloride contamination of ground water. That's because, if road salt applications were substantially reduced or eliminated, much of the chloride in lakes eventu- ally would be flushed out of lakes and streams by rains. But chloride in ground water would be longer-lasting. "In ground water, I think it is not reversible," Stefan said. "If we mess up the ground water, we have to live with it." In 1995 and 2005, the Minnesota Pol- lution Control Agency tested chloride in wells across Minnesota. Comparison of data from the two sets of tests indicated chloride concentrations had risen. But the 2005 tests involved a significantly higher number of urban wells, and the agency concluded the results were insuf- ficient to demonstrate a trend toward increased chloride contamination of ground water. Other research by the United States Geological Survey in 1998 found median chloride concentrations in shallow wells in the northwestern Twin Cities were nine times the median concentrations found in non-urban areas of Minnesota and Wisconsin. A 1999 USGS study in the Twin Cities found chloride concen- trations were significantly greater in wells down-grade from major 1lighways. The paper to be presented at the Road Salt Symposium is titled "Study of Environmental Effects of De-Icing Salt on Water Quality in the Twin Cities Metropolitan Area, Minnesota." That paper and the research it summarizes were paid for by a $108,000 grant from the Local Road Research Board, astate- funded transportation research agency. The summary paper is available at: http: / /home.safl.umn.edu/hstefan. Environmentalists, who long have focused on surface-water poIIutants such as phosphorus, sediment and mercury, increasingly are considering chloride to be a serious threat to water quality. Minnesota has seven creeks or rivers on its official list of "impaired waters." Five of the seven streams are in the metro area, and three of the seven were added to the list in 2008. "We're definitely seeing an increase in chloride in all our surface waters," said Brooke Asleson, project manager of the Minnesota Pollution Control Agency's watershed section. The agency recently awarded a $30,000 contract to a consultant to study chloride contamina- tion in surface waters across the metro area and devise a strategy for remedy- ing it. The Pollution Control Agency also has funded classes for snowplow operators on techniques for effectively clearing • ® ® • • s_• • • • e • o • • ® e ® ® ® ® • • • • ® • • o • • • _® The Freshwater S®ciety wits h®sts its nth ~nn~a0 ®a~ Sait ® Sym®siurr, ®n February ~ at the Earle Rr®wn Heritage Center in r®®k9yn Center ® Eric Novotny; a University of Minnesota doctoral student, will present ® recent research on the impact of road salt bn Twin Cities lakes. Glenn Skuta 0 of the Minnesota Pollution Control Agency will'talk about his agency's ® response to Minnesota`s chloride-impaired waters. ° Wilfred A. Nixon, a professor of civil and environmental engineering at ~ ® the University. of Iowa, will speak on national advances in snowremoval ~ • techniques that reduce the reliance on road salt applications. Scott Koefod • of Cargill will peak on research onnon-chemical .deicers. Research will also ~ be presented by the University of New Hampshire onporous pavements as ° non-chemical alternatives to road salt. ~ ® Other presentations are scheduled by representatives;of he University of ® Minnesota and the 1Vlinnesota Department`of Transportation. ® This year, the symposium again .will feature Environmental Leadership ® Awards to groups, individuals or companies #hat have changed their snow • ® and ice management. plans to reduce road salt pollution. • o For more information on :the 20fl9 symposium, contact: Jeamle Prok at ~ • 952-314-8133 or visit: www freshwater.org. • • • s • s c ® o c • • e ® s • • e o • • ~ ~ ® ~ ° c • o • ~ • • ® • snow and ice while using less salt. Many road maintenance supervisors are trying to strike a balance between saving lives by clearing icy roads and protecting the environment by using less salt. Rising salt prices also have spurred efforts to reduce salt application. Wayne Sandberg, Washington County's deputy public works director, chaired a technical advisory commit- tee that worked with Stefan and his research team, beginning in mid-2006. He said Stefan's research was significant because it demonstrated a clear link between road salt use and chloride in surface waters Sandberg said the research would influence highway professionals to try to limit-but not eliminate-their use of salt. There currently is no cost-effective substitute for salt as a road de-icer, he said. "I'd like to able to stop using salt, but the reality is we're going to keep these roads safe," Sandberg said. ` FACETS December 2008