A plan to protect Utah from US Magnesium’s toxic waste relies on something that is disappearing

By | Published Aug 07, 2023 | The Salt Lake Tribune
A plan to protect Utah from US Magnesium’s toxic waste relies on something that is disappearing

Add another potential disaster to the growing list associated with the shrinking Great Salt Lake: the implosion of the cleanup plan for the US Magnesium Superfund site.

The plan, finalized just two years ago, requires sufficient water to create a salt “cap” sealing in the toxic waste left should the company eventually close.

“That’s what the whole plan is predicated on — having saline water,” said Ken Wangerud, a regional Superfund remedial project manager for the Environmental Protection Agency.

But the availability of and access to that water is far from certain given the dramatic contraction of the lake in recent years. Moreover, feasibility studies for possible contingency plans were never completed, Wangerud said.

The US Magnesium, which mines magnesium and other minerals from salts extracted from the Great Salt Lake at a facility 40 miles west of Salt Lake City, has for years illegally disposed of highly acidic hazardous waste in a network of open-air, earthen ditches and a 400-acre waste pond that lacked adequate environmental controls, according to EPA documents.

It is unusual for the EPA to designate an industrial site that is still operational as a Superfund project. Superfund is the colloquial name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. The act was originally intended to fund the cleanup of long abandoned, environmentally hazardous sites like mines, where there was no owner or responsible party present to clean up the contaminants left behind.

However, the act also empowers the EPA to find and identify the parties who caused the contamination. Where such parties can be found, the EPA is authorized to compel them to clean up the hazardous materials. If the responsible party fails to do so, the EPA may intervene directly, forcibly cleaning up the site itself while billing those responsible for the EPA’s work. These authorities were included in the act with the intent of dissuading existing companies from trying to save money by abandoning contaminated properties instead of cleaning them up.

In the case of US Magnesium, an extended legal battle beginning in the early 2000s led the EPA to believe that taking charge of the site itself through a Superfund declaration was the agency’s best shot at containing the wastes it believed were still present and uncontrolled at the facility.

Even with the Superfund declaration in 2009, work at the site has progressed slowly and encountered numerous setbacks. For example, the waste in the US Magnesium lagoons is so acidic that it destroyed the laboratory equipment the EPA initially tried to use to analyze it, Wangerud said, forcing them to find a workaround.

Setbacks notwithstanding, the EPA and US Magnesium came to an agreement about cleaning up the waste — or portions of it, at least — that was ratified by the courts on June 30, 2021. Under the terms of the agreement, U.S Magnesium will build a new waste management system that encases its lagoons in what Wangerud describes as a giant subterranean box to ensure that the chemicals it contains will never leak out into the ecosystem again.

At the end of the facility’s life, the company is to use water from the Great Salt Lake to build a one-foot-thick salt flat over the top of the waste pit, sealing it off for good.

Whether there will be enough water left in the lake to implement the plan remains to be seen. So far, the EPA has not finalized a contract to secure the needed water. But talks about alternatives that would not rely on the lake may be in the works.

Pure magnesium, with a side of toxic chemicals

(Trent Nelson | The Salt Lake Tribune) US Magnesium, seen across the Great Salt Lake from Stansbury Island on Saturday, March 26, 2022.


US Magnesium is the largest producer of magnesium and the sole producer of primary magnesium, which is derived from raw rather than recycled materials, in the United States. The 51-year-old operation uses a process called electrolysis to split the salts in the Great Salt Lake into their atomic components, including sodium, potassium, magnesium and chlorine. This, Wangerud noted, produces an exceptionally pure form of magnesium, which was declared a “critical” mineral in 2022 by the U.S. Geological Survey on account of its importance to making metals and alloys.

But the company’s processes also produce massive quantities of chlorine.

In small quantities, chlorine is useful for the same reasons it is dangerous in large quantities: chlorine can damage and even kill living cells. Breathing too much raw chlorine gas is fatal; it became one of the first chemical weapons ever deployed when German troops released it against Allied forces in World War I.

But chlorine by its nature doesn’t like to exist as a pure gas. It prefers to link up with other molecules to form chemical compounds, some of which you might be familiar with. Sodium chloride – chlorine plus sodium – is table salt. That’s what is in the Great Salt Lake.

Chlorine can combine with other substances as well. Some of the trickiest chlorine compounds, called organochlorides, form when chlorine bonds with carbon.

US Magnesium does not intentionally manufacture these chemicals, but they occur at the site as a byproduct of the company’s processes, according to John Mackey, director of the Utah Division of Water Quality.

This is what concerns the EPA and state regulators about the contamination at US Magnesium: soil, ponds and even the air around the plant contain not only vast quantities of chlorine gas and, yes, hydrochloric acid, but also a swath of organochlorides, including dioxins, furans and a chemical called hexachlorobenzene.

Hexachlorobenzene was used as a pesticide and preservative until 1965, the year before it was formally banned in the U.S.; it was later banned internationally under the 2004 Stockholm Convention on Persistent Organic Pollutants. Animal studies suggest long-term exposure can trigger liver, thyroid and kidney cancers, but the main reason hexachlorobenzene and other organochlorides are now considered major environmental concerns is their tendency to build up in the food chain.

Given the company’s line of work, it’s not likely that humans will directly consume hexachlorobenzene or any other pollutants present at US Magnesium.

“People just don’t go there, and people who do are most likely people who work out there and who are aware of the risks,” Mackey said.

But wastewater from the company’s ponds has leaked out into the groundwater beneath the plant and by 2016 it had made its way to the Great Salt Lake, according to a Nov. 21, 2016, warning to US Magnesium from the Utah Department of Environmental Quality.

Once in the lake, chemicals from the plant could be taken up by microorganisms and wildlife living there. What the EPA and the state do not want to see happen, Mackey said, is for birds that migrate thousands of miles each year across the Western Hemisphere to be exposed to toxins while rooting around in sediment around the Great Salt Lake looking for food.

The good news here, Mackey said, is that organochlorides do not move quickly. The existing contamination remains restricted to a relatively small area, and US Magnesium is expected to begin construction of a subterranean wall to cut off the contaminated area from the lake this year, which should prevent widespread contamination that could harm migrating birds.

Everyone has some time to make it happen, Mackey said, but “it’s really worth it in the long term to make sure these materials are isolated and to prevent them from drifting from places where they are under control, into places where they are out of control.”

Salt Cap Solution

While the chemicals at the site could in theory be eliminated by “thermal destruction” — burning them up — Wangerud said, the problem is the amount of contaminated material at the US Magnesium site.

“It would be just a mindbogglingly costly endeavor, and it might require that you take all the natural gas produced in the state of Utah to fire the gas turbine flame,” he said.

That left the EPA with the challenge of finding a way to contain the contamination since there wasn’t a feasible way to destroy it.

The company and the EPA arrived at a solution that would involve building a giant retaining pond surrounded by impermeable barriers designed to keep the waste in a single location. A layer of clay that underlies the US Magnesium site will form a “floor” for the lagoon, and the company has agreed to build retaining walls down to the level of the clay on the north, south, and east sides of the pond. The western side will be left open on the theory that the pressure from the natural downslope flow of water from the surrounding mountains will hold the waste in place inside the three-sided box.

There is still some debate as to whether the three-sided box solution will be adequate to prevent future leaks of waste into the lake, said William Johnson, a geology professor at the University of Utah who has worked as a consultant to environmental group Friends of Great Salt Lake on the US Magnesium Superfund proceedings.

But overall, he agrees it should be an effective solution.

“This will be a significant engineering feat,” he said, “but the concept is good, a huge improvement over previous and current practice.”

The top of the box will also remain open so that US Magnesium can continue to deposit waste in the lagoon so long as the company remains operational. And it is expected to keep running for some time, Wangerud said, thanks to the company’s near-monopoly on a critical mineral for which there is no conceivable alternative.

“I can’t imagine a replacement or substitute product coming along,” he says. “I won’t even think about a future time frame for that.”

But should the day come when US Magnesium is done with the pond, it will use its existing pumps to draw in water from the Great Salt Lake, and nature and evaporation will take their course and build, essentially, a mini salt flat to ensure the materials in the pond remain contained there.

There is, Wangerud said, just one flaw in the plan — a huge one: “The notion that hey, Mother Nature will lay down salt for us, and the only thing we need to do is pump that water and let Father Sun boil it off and leave the salt behind—well that’s pretty great if you have salt water to pump.”

Uncertain Future

(Trent Nelson | The Salt Lake Tribune) The US Magnesium dike north of Stansbury Island on Saturday, March 26, 2022.


Max Greenblum, an EPA attorney, acknowledged that it would likely be impossible to execute the salt cap closure plan as envisioned if the lake dries to such an extent that US Magnesium’s pumps run dry.

The EPA’s settlement with US Magnesium calls for both a closure bond, providing money for the federal government to complete the cleanup if the company doesn’t, and for US Magnesium to deed the EPA 4,000 acre feet of the water rights owned by the company in order to guarantee the agency would have the capacity to seal off the contaminated waste pond. Four thousand acre feet is enough water to supply 4,000-8,000 new homes; US Magnesium drew just over 50,000 acre feet of water from the lake last year.

The settlement documents include a copy of a contract that would assign the applicable water rights to the EPA, although that contract has not yet been signed or finalized, Greenblum said.

The right to the 4,000 acre feet of water is, whether US Magnesium or the EPA owns it, an absolute right like a property right, said Ben Stireman, deputy director of the Utah Division of Forestry, Fire and State Lands, which oversees management of the Great Salt Lake. So long as the water exists, the owner has a right to use it.

But whether US Magnesium will be able to access that water with its pumps at low water levels is an entirely different question — one Stireman said he honestly could not answer.

The Great Salt Lake hit a record low of 4,188.5 feet in November 2022 after years of decline, prompting fears that the lake was on the cusp of complete environmental collapseResearchers believe the lake’s decline is a result of both increased evaporation due to the warming climate, and the diversion of water away from the lake for human consumption.

The southern segment of the lake rose more than four feet this spring in response to record snowfall around the state, but has begun to drop again in the heat of the summer months.

Stireman said the state and the EPA have met to discuss the salt cap closure plan and possible alternatives in light of the lake’s uncertain future. As these conversations with the agency began this summer, Stireman said it was too early to share details about solutions that may be in the works.

The state would support the use of water from the lake if it is the only way to remediate the US Magnesium site, Stireman said, “but we are going to look at other options and see if the EPA is amenable to other options.”

Longer, Deeper Canals

While the company grants that it is hypothetically possible for low lake levels to prevent the construction of the salt cap as envisioned, Tom Tripp, director of technical services and development at US Magnesium, said it is unlikely that such a scenario would actually occur.

US Magnesium intentionally built its plant near the deepest part of the Great Salt Lake in order to mitigate the impact of the lake’s naturally fluctuating water levels, Tripp said. And the company maintains a 20,000-acre pond of salt brine that could act as a reserve to keep the company operational in the event that it loses access to the lake for a time. The pond runs three to five feet in depth, depending on the time of year, Tripp said.

“You would have to be in a situation where the company quit operating for quite a while” before it closed for US Magnesium to lose access to adequate salt water to execute the salt cap plan, Tripp said.

US Magnesium currently has the capacity to pump water from the lake down to an elevation of 4,186 feet above sea level, Tripp said. The lake’s record low last fall put the company within a few feet of that minimum.

Low water levels prompted US Magnesium to file an emergency application to dredge longer and deeper canals that would allow it to continue pumping water at lake elevations as low as 4,185 feet. But Tripp said the application, which US Magnesium is currently revising in response to questions from officials who nixed the company’s initial request last year, was a preemptive measure.

Although state records estimate that the company’s use of water from the lake dropped from more than 71,000 acre-feet of water in 2018, to just under 51,000 in 2022, Tripp said that the reduced water use was a result of excess inventory and a lack of available storage for additional product at the US Magnesium site. He also said the company had voluntarily reduced its water use as part of statewide efforts to conserve. However, the state has said that the company’s reduced water use is because they have had trouble accessing the lake through their canals.

Tripp said it was his personal opinion that no amount of conservation would change what he believes are natural fluctuations of the lake.

“I’m just saying the lake is a natural water body that in the last 12,000 years has had great swings in its level,” Tripp said. “Everyone is concerned that we got down to 4,188.5, but in the last thousand years it has gone completely dry three times. We just weren’t here to witness it.”

‘Failure is not an Option’

Friends of Great Salt Lake remains concerned about some aspects of the US Magnesium settlement, with ongoing questions about whether the plan to use water pressure from the surrounding mountains to contain the waste at the site could allow contaminants to eventually leak out into groundwater once again. The organization also protested US Magnesium’s request to build longer canals to ensure access to the lake.

But the salt cap itself hasn’t drawn attention from the group, mainly because they believe any damage caused by its failure would pale in comparison to the environmental damages that would result from the lake’s environmental collapse, according to Friends of Great Salt Lake attorney Rob Duboc. In addition to providing critical habitat for millions of migratory birds that use the lake as a rest stop during their seasonal journey across the Western Hemisphere, the lake also supports an estimated $1.32 billion in annual economic activity within the state of Utah. The lake’s sediments have also accrued heavy metals and other harmful chemicals from a variety of sources; scientists believe these contaminants could begin to sicken Utah residents as the lake shrinks and exposes the sediments beneath it.

Duboc said he rejected outright the premise that the lake would shrink to an extent that would jeopardize the salt cap, because the lake must not be allowed to drop any lower than the record set last November.

“Failure is not an option,” he said. “That is our position. The state is going to have to find the water necessary to ensure the viability of the lake’s ecosystem.”

The settlement does allow the EPA to force US Magnesium to draw up an alternative closure plan should the EPA determine, at any point, that the salt cap plan is no longer feasible. There’s no particular trigger point included in the settlement, however. That’s because, Greenblum said, the EPA wanted as much flexibility as possible so it could respond to new technologies and environmental changes at the site.

“In full transparency, there is not a person at EPA whose job is to sit there every single day determining the viability of the closure plan,” he said. But at least for now, “it’s something the EPA continues to monitor, and this facility is very much on the EPA’s radar.”


The following story was reported by The Utah Investigative Journalism Project in partnership with The Salt Lake Tribune, with support from the McGraw Center for Business Journalism at CUNY’s Craig Newmark Graduate School of Journalism.

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