SALT LAKE CITY -- Utah's Great Salt Lake has been protecting the Wasatch Front from a potential health hazard for 150 years, but that protection is threatened, say some scientists, by a growing, thirsty population and a drying climate.
Simply put, the problem is dust. The Great Salt Lake has been approaching its lowest level on record, which means much of the shoreline is an exposed, dry lake bed adjacent to 1.75 million residents of the Northern Wasatch Front.
Geology and Geophysics professor William Johnson has studied the lake for years, looking at what is in the sediment of the lake bed.
"Any kind of influence we have on the level of the lake could potentially impact the amount of exposed lake bed, which could impact the amount of dust generated," Johnson said.
Johnson’s research, done with former students Greg Carling Diego Fernandez, showed a far-reaching impact of dust storms on Utah's mountain snowpack.
"It changes the ability of the snow to reflect the sun," Johnson said.
Johnson explained that snow, in its pure form is almost perfectly white, making it perfectly reflective. Reflection pushes heat away, and the snow melts slowly. Put a layer of dust on the snow, and it's like wearing a dark shirt in the sunlight. It absorbs heat and the snow melts quickly.
Johnson said that exacerbates a problem already created by a changing climate.
"We're certainly experiencing increased temperature and we'll continue to do so according to all the models that exist, and we're augmenting that with dust deposition on the snow," Johnson said.
Johnson said the dust effect on snow is proven, and the health consequences of Pm10 dust that might come off the lake are known to public health authorities.
But there is a large unknown as well: the lake sediment contains large amounts of heavy metals: mercury, selenium, arsenic, and others. So far, no one has studied the possible impact of airborne dust in the Salt Lake Metropolitan area containing those contaminants.
"We need to understand better the trace element concentration in the dust and how it affects people," Johnson said.
But water managers along the Northern Wasatch Front are still looking for new sources of water for the rapidly growing Metropolitan area.
"In particular the number that's being looked at right now is the doubling of the population by 2060," said Marisa Egbert, an engineer in charge of the Bear River project with the Utah Division of Water Resources.
The Bear River Project was mandated by the Utah legislature in 1991. The goal is to find places to dam the largely untapped Bear River, creating reservoirs to provide 220,000 acre feet of water annually to Weber, Davis and Salt Lake Counties.
The project is estimated to cost $2 billion, most of that money coming from the State to be paid back over time by the Weber Basin and Jordan Valley Water Conservancy Districts.
The Bear River is the largest source of water to the Great Salt Lake and conservationists are growing increasingly upset by the possibility of putting more reservoirs upstream.
The two other rivers flowing into the lake, the Weber and Jordan, already have reservoirs upstream.
The potential impact of reservoirs along the bear is largely unknown. A study conducted when the lake was approaching record levels in the 1980's estimated reservoirs storing 220,000 acre feet on the Bear River would lower the Great Salt Lake by 6 inches.
Environmentalists say that in current conditions, the impact would be more like 2-4 feet.
"The Great Salt Lake ecosystem could crash as a function of Bear River development, but instead of having a robust dialogue about if we should pursue this, it's taken for granted that we need it," said Zach Frankel, Executive Director of the Utah Rivers Council.
That ecosystem includes migratory birds, brine shrimp and a whole lot of mineral-rich water, each of which supports multi-million dollar niches of the Utah economy.
"To the extent that the lake depletes any further, we have operational problems," said Keith Morgan, the facility manager for Morton Salt's Great Salt Lake operations, "So today was the first I'd known about the potential impacts of the Bear River water project."
Morgan said a six-inch decrease from current lake levels would put the lake beyond the reach of their pumps.
The lake is already near historically low levels. Harbor Master Dave Shearer at the Great Salt Lake Marina knows that better than anyone.
"We have 60 percent of the boats here at the Great Salt Lake stuck in the mouth of the marina," said Shearer of the Lake's largest marina with 320 slips and a normally active sailing community.
"Very often when they leave, they just don't come back, it's like giving up the fight to some degree," said Shearer.
The Great Salt Lake's second biggest marina located on Antelope Island, has only enough water for canoes, kayaks and paddle boards. Most of the slips are sitting on dry ground.
The reason for the low levels on the lake is largely beyond the control of residents along the Wasatch Front.
"What we do as citizens and humans here in Utah is a very minor component than what happens," said Todd Adams, Deputy Director of the Utah Division of Water Resources.
Adams points to the cycles of weather and climate that have always shown fluctuations in lake level.
Cory Angeroth, Supervisory Hydrologist with the U.S. Geological Survey makes a similar point.
"There's evidence of instances in the past when the Great Salt Lake has been significantly smaller than it is right now," said Angeroth.
But Angeroth made the point to describe why Utahns should avoid contributing to low levels.
"If we go towards a warmer, dryer trend then yeah, the Great Salt Lake could get lower and lower," Angeroth said.
Johnson said a warmer, dryer trend is likely.
"We're certainly experiencing increased temperature and we'll continue to do so according to all the models that exist and we're augmenting that with dust deposition on the snow," said Johnson.
The question and primary disagreement between the state and conservationists is whether Weber, Davis and Salt Lake counties could get by without Bear River water.
The U.S. Geological Survey researched public water use nationwide in 2005 and found that Utah consumed more water per capita than any state but Nevada. 186 acre feet compared to a national average of 99.
But Todd Adams says Utahns are beginning to change that.
"Currently the state of Utah per capita water use is reduced about 18 percent, so if I could say anything at all it would be way to go citizens of the state," said Adams.
Zach Frankel said Utah has fallen behind.
"There are scores of communities across the American West that have doubled in population, but have pursued real conservations programs and have not increased their water use," Frankel said.
The choices with how to handle such a valuable resource will cause sacrifice in any direction.
Immediate conservation would mean paying more for water and changing habits significantly, including far fewer green lawns.
More Reservoirs would mean a lower Great Salt Lake, with potential health hazards from what sits on the bed of Utah's inland sea.