Utah’s Great Salt Lake may not be so salty after all as a recent study appears to have detected a large freshwater reservoir underneath.
Located in northwestern Utah, the Great Salt Lake is the largest saltwater lake in the Western Hemisphere and the eighth largest in the world, according to Utah’s Department of Natural Resources. In November 2022, the average daily lake level hit a new record low, dropping to 4,188.5 feet above sea level, the department said.
In a study published in Scientific Reports in late February, airborne electromagnetic surveys were used to examine the area underneath Farmington Bay and Antelope Island off the lake’s southeastern shore.
University of Utah researchers analyzed the data, finding freshwater saturates the sediments beneath the lake’s salty surface to depths of about 10,000 to 13,000 feet.
“We were able to answer the question of how deep this potential reservoir is, and what its spatial extent is beneath the eastern lake margin,” the study’s lead author, Michael Zhdanov, said in a press release about the study issued last month.
“If you know how deep, you know how wide, you know the porous space, you can calculate the potential freshwater volume.”
The study is part of a larger research project to understand groundwater beneath the Great Salt Lake, which was prompted by the appearance of mounds covered in reeds, or tall grasses, on the bed of Farmington Bay in recent years.
Declining water levels in the lake have caused dust pollution, which contains toxic metals and blows into Utah’s communities. The hope is to determine whether the groundwater can be safely tapped to reduce the dust.
“There are beneficial effects of this groundwater that we need to understand before we go extracting more of it,” Bill Johnson, a co-author of the Great Salt Lake groundwater research papers, said.
“A first-order objective is to understand whether we could use this freshwater to wet dust hotspots and douse them in a meaningful way without perturbing the freshwater system too much.”