Utah road and street officials are worried about a Canadian study that concluded road salt may be a greater hazard to groundwater than previously thought.
The study published this month in a Geological Society of America newsletter, said highway officials long have assumed most road salt is washed away in streams and has little effect on groundwater."However, there is now evidence that continued deployment of road deicing chemicals may compromise groundwater quality for generations to come," hydrogeologist Ken Howard, head of the University of Toronto research team, and his colleagues wrote.
The findings indicate "the potential hazard for groundwater is much worse than people have realized," said Eldridge Moores, a geologist at the University of California, Davis. "We've got a major problem, but I don't see any solution to it."
About a third of the drinking water in the Salt Lake Valley is pumped from groundwater. Aquifers also provide about two-thirds of the water used statewide, although much is for irrigation.
"We have a great deal of concern" about salt pollution of groundwater, said Jay Devashrayee, an environmental engineer for the Utah Department of Transportation.
If research shows Utah's groundwater is being tainted, the agency will have to modify its road-management plans, Devashrayee said.
If road salt were banned, there would be more traffic accidents, officials fear. The matter will be examined as part of a groundwater-pollution study, said Fred Pehrson, who oversees monitoring for the Utah Division of Water Quality.
Tosh Kano, Salt Lake County assistant director of public works, said he is distressed by the new study "because right now, the cheapest way to provide the greatest amount of safety is using salt to de-ice."
Kano said road salt costs $13 to $15 per ton while an environmentally safer chemical costs $600 per ton.
The study in metropolitan Toronto found while 45 percent of road salt is washed away by streams, 55 percent enters shallow underground water and percolates toward deeper aquifers.
Researchers had assumed salt levels in groundwater had reached a maximum level, but the study indicated sodium and chloride pollution of groundwater in Toronto will continue to worsen for 200 years before reaching its worst concentration.
Bob Barnes, an environmental scientist at the Division of Water Quality, believes water would be more likely to soak into the ground in Toronto. Here, storm drains may carry a lot of salt-tainted water into the Great Salt Lake, he said.
Howard, however, said Utah has far less precipitation, so the state's groundwater "may end up with a higher concentration (of salt) as a result."