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BYU Geochemist Plays Detective with Water and Dust

Photo by outkast9821

Wind carries a particle of dust from the dry lake bed to the mountain snowpack. The snowpack melts, and the water flows down streams and rivers, through a pipe, and to the tap.

Dr. Greg Carling specializes in the fields of geochemistry and hydrogeology. Particularly, he studies metal and nutrient cycling, discovering where contaminants originate and how they end up in the water we drink or the air we breathe.

“If you think of the hydrologic cycle, you have water evaporating off the oceans, getting in the clouds, then raining down. There is also this cycle of metals and nutrients going on,” Carling said. “They can be transported through the atmosphere, land on the snowpack and in the watershed.”

Water chemistry first interested Carling while he was a geology undergraduate student, and he pursued the topic in more depth as a graduate student. His research seeks to answer the question of how a water sample picks up its chemistry and how this knowledge can lead to better solutions to keep water clean.

“Obviously, we all need clean water to survive, to drink, to recreate in. We need rivers and lakes,” Carling said. “We live in the desert, so we need to understand what our water resources are and how we can protect those resources to keep three million people in Utah alive.”

His interest in studying water chemistry led him to an interest in dust. Wind-blown dust can transport metals and nutrients from a dry area to a water source. In a desert area such as Utah, there are many places where a dust particle might originate, and it takes first knowing the source to then prevent harmful dust. Enter geochemists.

“We’ve found a way to fingerprint dust from the different playas—playas are just dry lakebeds,” Carling said. “Based on that fingerprint, we can take a sample from the snowpack and give you a good idea of where the dust actually came from.”

One area Carling focuses on is the Great Salt Lake. While this year’s wet weather helped, Carling says long-time drought and water diversions are causing the Great Salt Lake’s water level to drop.

“As water levels drop, it exposes more lakebed that can produce dust,” Carling said. “We’re trying to see how much of that dust is affecting the Wasatch Front, and we’ve shown that there’s quite a bit of it that can affect our air quality.”

Though he specializes in water quality, Carling’s interest in dust led him to research air quality as well.

“We breathe [dust] in, and it can cause problems, especially in children or the elderly. Then that dust lands on the snow pack and causes a whole other set of problems,” Carling said. “For one, when you get dust on snow pack, it causes the snow to melt earlier because it makes the surface darker so it absorbs more sunlight. Then it can affect water quality in these otherwise pristine areas.”

Carling started researching as an undergraduate student at BYU. He worked with Dr. Alan Mayo (now professor emeritus) and Professor Dave Tingey. Now Carling has his own students working with him on his many research projects.

“A lot of this research takes so much field work and lab work, and I could never do it all myself,” Carling said. “I need students to take ownership of these projects or pieces of the projects.”

Usually, he’ll have a few graduate students and around ten undergraduates working for him at any given time. Carling said he typically has one or two graduate students working on a specific project, and then several undergraduates to help each graduate student. For instance, his graduate student Tim Goodsell researched the arsenic sources in Heber Valley, Utah.

“He found that some of the hot springs in Heber Valley have really high levels of arsenic, and that arsenic ultimately gets into the Provo River. So that gets into our drinking supply,” Carling said. “It’s not at high-enough levels to be harmful once the hot spring water is diluted by the Provo River, but it’s still something to watch.”

Another student, Matt Randall, recently completed a project studying phosphorus accumulation in Utah Lake. The volume of phosphorus directly affects the amount of algae in the lake. In the summer of 2016, the lake was closed to the public because of its large, toxic, algal bloom.

“Phosphorus is one of the nutrients that the algae need to grow, but when you have too much of it, the algae can go crazy,” Carling said. “What we found is that there’s lots of phosphorus stored in the sediments at the bottom of Utah Lake.”

The phosphorus accumulated over the last century, according to Carling, and this makes remediation particularly challenging. A clean lake means first stabilizing the phosphorus so that algae can’t use it.

Carling also recognizes that knowing how to share research findings is just as important to the community as the research is.

“We present to scientists from a scientific standpoint, but then we present stuff to the local managers from a practical standpoint just to make sure that what we’re finding might help somebody down the line,” Carling said.