AUTC project number: 107035
Ming Lee (UAF)
Alaska averages about 70 inches of snowfall a year across the state, from around 600 inches in Thompson Pass, near Valdez, to a measly 30 inches in Barrow. Managing snow and ice on the state's streets and walkways is a hefty annual budget item. Regular maintenance operations often include plowing and salt distribution, usually sodium chloride (NaCl), which is available, inexpensive, and capable of lowering the freezing point of water, usually melting ice at moderately low temperatures. One problem with using sodium chloride as a de-icer is that it is only minimally effective at pavement temperatures of less than 20°F. For Interior Alaska, where temperatures can sometimes hover around -30?F for weeks, 20?F can seem like a balmy dream. At the same time, environmental concerns about additives that land in the roadside soil and find their way into the water table are increasing,and some traditional practices for snow and ice control are becoming unacceptable. Researchers for this project,headed by Ming Lee and David Barnes of the UAF Civil & Environmental Engineering Department, have analyzed the results of conductivity and chloride concentration tests performed on soil and water samples collected in the study area (Fairbanks) in April, after snow and ice begin to melt. Their findings suggest that AKDOT&PF's salting practices in the northern region do not cause conductivity and chloride levels to exceed limits set for waste water and agricultural regulation. Also, the road salt used showed no heavy metal content exceeding existing federal guideline limits.