Drought Could Raise Toxic Dust Around Utah’s Great Salt Lake

10:20 minutes

Dried, dusty, rocky ground on the lower two-thirds of the image. In the near distance, white mounds of salt pile high at the waterline of the lake. Utah's mountains rest in the far background.
The vanishing Great Salt Lake with salt mounds in the distance. Credit: Shutterstock


Utah’s Great Salt Lake holds a unique ecological niche as the western hemisphere’s largest saltwater lake. The body of water is three to five times saltier than the ocean, with salinity ranging between 12 and 28 percent. According to the Great Salt Lake Institute, millions of birds from more than 250 species rely on the lake yearly, alongside a diverse variety of plants and animals. 

Like many bodies of water in the U.S., climate change is affecting the status quo in the Great Salt Lake. The water is drying up at an alarming rate, reaching its lowest level in recorded history this month. Now, researchers warn that toxic dust could increase as water levels continue to drop.

Joining Ira to discuss the Great Salt Lake’s ecosystem and future is Bonnie Baxter, director of the Great Salt Lake Institute and biology professor at Westminster College in Salt Lake City, Utah.

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Segment Guests

Bonnie Baxter

Bonnie Baxter is director of the Great Salt Lake Institute and a biology professor at Westminster College in Salt Lake City, Utah.

Segment Transcript

IRA FLATOW: Utah’s Great Salt Lake has been dealing with unprecedented drought for years. This is bad news for the largest saltwater lake in the Western hemisphere because the Great Salt Lake is so, well, salty. It’s home to a diverse ecosystem, and many plant and animal species rely on it. Since the Great Salt Lake is shrinking so fast, some researchers are warning that toxic dust could be tossed up as things get drier. So what does this mean for the creatures that call the Lake home and the communities around it?

Joining me now is my guest Dr. Bonnie Baxter, Director of the Great Salt Lake Institute and biology professor at Westminster College in Salt Lake City. Welcome back to Science Friday.

BONNIE BAXTER: Oh, hi. Nice to be here again.

IRA FLATOW: Thank you. Can you explain what makes the Great Salt Lake so special for us?

BONNIE BAXTER: Well, so many things. I guess if we were to start with the ecosystem, it’s the most important body of water on the Pacific Flyway, a stopover for 10 million birds. That’s a lot of birds.


BONNIE BAXTER: And those birds in the Lake, they eat two invertebrates, the brine shrimp and the brine fly, which have their larval and pupil stage in the Lake. And there are other invertebrates in the freshwater wetlands that feed some birds. But when you think about the Lake proper, it’s basically this food chain of 10 million birds eat two invertebrates. And so that’s pretty cool in terms of the biomass that it produces.

And also, for the local population, we have about 8,000 jobs on Great Salt Lake between the mineral extraction companies that make salt and soon-to-be lithium, and also the brine shrimp companies that harvest the encysted embryos of the shrimp that are sent around the world in aquaculture. So the Lake has an economy.

And if you think about the Lake effect on the snow, a lot of the skiing that happens around Salt Lake City in our mountains is due to that Lake effect, the big, wet sink that the storms blow over and make what we call the greatest snow on Earth. So that’s an industry that we want to protect as well. So there are a lot of ecosystem services that this Lake does in addition to just being a really cool ecosystem.

IRA FLATOW: So the Lake has been drying up for years. So is the story here that climate change has been speeding this up or exacerbating what’s going on?

BONNIE BAXTER: Yeah. I think the way we see it is that, for about a century, we’ve been doing diversions from this Lake, and so this is a terminal Lake. And if you think about a bathtub, it’s like the puddle at the bottom of the bathtub. And any water you take upstream doesn’t make it down to the bottom. And so if we build more housing developments or we increase the amount of agriculture upstream, those activities use water, and that water never makes it down to the bottom of the watershed.

And so this is one of the largest watersheds in the country. And I think that we need to be really cognizant of what water is getting to the Lake and what isn’t. So those diversions have happened historically for all these reasons, and that means the Lake has been shrinking. But not just the Lake has been shrinking. Those aquifers that provide rebound on dry years are not working.

So we’re in a situation now where we’ve set ourselves up for failure. So now we’re approaching the high temperatures of climate change and the change in precipitation that we’re seeing, which is less snow and more rain, and that leads to more evaporation. So that water doesn’t make it where it needs to go. So the way I see it is we’ve been diverting water that has caused a crisis that allows us to not be able to rebound when we hit these pressures of climate change.

IRA FLATOW: Mm-hmm. And let’s talk about the potential for toxic dust, right?


IRA FLATOW: As the Lake is drying up, you have this dust. What are researchers warning that could happen?

BONNIE BAXTER: Well, many of your listeners may know the Owens Lake story that happened not so far from Great Salt Lake. Owens Lake was a body of water in California that basically was sucked dry by water-thirsty LA, and it became a dust bowl, essentially, and produced the highest measured PM 2.5 particle pollution in the United States, the highest–

IRA FLATOW: That’s the particle size, right?

BONNIE BAXTER: Yes. Yes. And that’s the particle size that can be really detrimental to human lung tissue. So that Owens Lake catastrophe– we’ve done this experiment before where we’ve drained a body of water and let the dust fly around. That Owens Lake catastrophe, that lake is one tenth the size of Great Salt Lake. So we’re talking about a Lake bed that is 10 times the size of Owens Lake. And we’re a little frightened about just the air pollution that will come from this.

If you couple that with a history of mining in the Western United States, you understand that there are also heavy metals in this Lake bed because a terminal lake doesn’t let go of anything. It holds the memory of everything it’s encountered. So metals that have come from gold smelting, for example, makes airborne mercury. We have a methylated mercury problem in Great Salt Lake.

We have selenium from mining that is also a byproduct. And then we have a natural level of arsenic. So those things are in this Lake bed, in this salt playa. And as the Lake dries up, they will become airborne as well. So it’s not just an air pollution dust storm, but it’s a dust storm laden with heavy metals. And that is what we’re frightened about.

IRA FLATOW: This is Science Friday from WNYC Studios. In case you’re just joining us, we’re talking to Bonnie Baxter about the drought in Utah’s Great Salt Lake. So are people planning to do something about it? And what could you do about it?

BONNIE BAXTER: Well, the big secret is the Lake needs water. I mean, that’s really how we solve this problem. One of the ecosystem services this Lake is doing is keeping that dust at bay. Making the Lake bed wet prevents this.

IRA FLATOW: You just can’t wish water to be there, can you?

BONNIE BAXTER: No, you can’t. And it’s really entangled in old water laws in the West. Federal water laws that were developed during the Homesteading Act really actually still govern water rights in the West. So solving this problem, it’s not just a science problem. It’s a policy problem, and it’s a water law problem.

So we all have to really think hard and work together. Luckily, the state agencies have really come to the table. The Utah legislators really came to the table this past session, voted on a number of pieces of legislation that could result in getting more water into the system. So we scientists are really grateful that they’re heeding our warnings locally. And there’s stuff going on at the federal level as well.

IRA FLATOW: Such as?

BONNIE BAXTER: Well, so there’s a recent bill that was introduced into both the House and Senate that would do two things. It would give some money to federal agencies to monitor saline lakes in the West, probably coming through the USGS, I think. And then the other thing it would do is explore engineering solutions to potentially get more water to the Lake, which there hasn’t been funding for that, so that would be pretty amazing.

IRA FLATOW: So are people optimistic that they’re going to get something done in time to prevent this toxic dust from hurting people?

BONNIE BAXTER: Well, optimism is– depends on what day–

IRA FLATOW: Is that all you have left?

BONNIE BAXTER: Yeah, right.

IRA FLATOW: Optimism is not a policy.

BONNIE BAXTER: I’m an optimistic person. And lately, I’ve been extremely pessimistic because it’s– I’ll just mention I was there last week doing some field work with students. And I was out at Antelope Island. And Antelope Island is an amazing place in itself, an island which has an original herd of bison that were brought from the last 500 bison that were left in the West in the 1800s and placed on this island. And there’s antelope and coyote, and it’s just an amazing place.

So I was sampling out there. And first of all, it isn’t an island anymore. It’s a peninsula because the Lake has shrunk so much. I’m studying microbialites. Stromatolites, for example, are a type of microbialite. They’re all dry. They’re out of the water. And that is shocking.

And then the ones that are still in the water, the water is getting too salty for them. So I was just there a month ago, and I see something incredibly different every time I go. So it’s hard to be optimistic when I’m seeing these changes before my eyes. So it’s obvious, it’s obvious in real time, and that makes it hard to be optimistic. But I do–

IRA FLATOW: I’m so sorry hear about that.



BONNIE BAXTER: It’s terrifying. And I do have hope, just because there’s so many people like you who are talking about the problem. And I really appreciate the attention to the Lake, and I appreciate all that folks and government can do to help on these policy issues. So that gives me some optimism, just that people want to hear about the problem.

IRA FLATOW: Yeah. Well, we’re talking about it, and we hope that something will happen. We wish you success and good luck in getting change–


IRA FLATOW: –and getting that water in there.

BONNIE BAXTER: Thank you so much.

IRA FLATOW: Dr. Bonnie Baxter, Director of the Great Salt Lake Institute and biology professor at Westminster College in Salt Lake City, Utah.

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