Utah has the fourth most toxic chemical releases of any state. The majority come from one source.

More than 80% of the toxic chemicals released in Utah in 2022 came from a mining company, according to the Environmental Protection Agency.

Just down the hill from homes and a park in Copperton Metro Township sits a leaching reservoir and two large, lined pools stained by copper residue.

The leaching reservoir — dubbed the “Bingham Creek Reservoir” on Google Maps — is owned by Kennecott Utah Copper Corporation and stores wastewater from the Bingham Canyon Mine, one of the largest open-pit copper mines in the world and a massive source of toxic chemicals.

The Rio Tinto-owned mine produces copper used in electric motors and power lines, tellurium for solar panels and, in smaller quantities, such other precious metals as gold and silver.

As it does so, the mine also releases millions of pounds of arsenic, lead, selenium, mercury and other toxic chemicals – ones that can damage the brain and nervous system, cause insomnia and cause cancer – every year, according to data from the U.S. Environmental Protection Agency’s Toxic Release Inventory, or TRI.

Many of those chemicals come to rest in massive tailings ponds to the north, and Kennecott gathers and disposes of the crystals left behind as the water evaporates.

Because the mine moves “millions of tons” of dirt and rock a year with “naturally occurring trace levels of metals” reportable to the federal government, the facility is a big TRI contributor, according to a statement sent by Tammy Champo, spokesperson for Rio Tinto Kennecott.

Those releases are “safely stored in specifically sited, engineered, constructed and permitted facilities,” Champo said, including the tailings ponds just north of Magna and east of The Great Saltair.

Sometimes, though, those chemicals make it into the surrounding environment.

Those don’t end up connecting directly to a toe tag saying “Rio Tinto did this” or a footprint linking a heart attack to the chemicals, said Dr. Brian Moench, president of Utah Physicians for a Healthy Environment.

“But given all the pollution and the toxins, we know some of these can be directly attributed to that,” Moench said. “We just don’t know exactly which ones.”

The Kennecott mine and smelter decreased toxic releases between 2021 and 2022, Champo said, and is working to further reduce releases through efforts like soil remediation and trucks with higher-efficiency engines that output fewer tailpipe emissions.

‘Contamination steadily gets worse year by year’

(Trent Nelson | The Salt Lake Tribune) The Bingham Copper Mine on Wednesday, March 20, 2024.

Moench has lived in Utah his entire life. He can name 15 families in his neighborhood who have had an episode of cancer.

Poisoned air and water, in part caused by toxic releases from facilities like the Bingham Copper Mine, may be to blame.

Between 70% and 90% of cancer cases can be traced back to behavior and environmental causes, a study by a group of researchers at Stony Brook University found in 2016. An example of a cancer-causing behavior is smoking, while exposure to dangerous chemicals and heavy metals in the air can be an environmental cause.

“This is an operation that releases environmental toxins to the community and has done so for 120 years,” Moench said about the Bingham Canyon copper mine. “The level of contamination steadily gets worse year by year.”

“The impacts are difficult to attribute exactly to their operation, but we know they’re there,” he added.

Many of the toxic releases by the Bingham Canyon Mine are known carcinogens, like arsenic, asbestos, cadmium and nickel compounds, according to the National Cancer Institute.

Lead and lead compounds are the mine’s largest toxic releases.

Lead exposure, according to the EPA, damages the brain and nervous system, especially in children six years and younger, leading to lower IQs. The U.S. Centers for Disease Control and Prevention warns that there is no safe level of lead in blood for children.

Adults experiencing lead exposure are at greater risk of high blood pressure, reproductive issues and nerve disorders from lead exposure.

The mine also releases mercury, a harmful neurotoxin. Mercury, when inhaled, can lead to emotional changes, insomnia, headaches and inhibited mental function, the EPA says.

These toxic releases have a compounding effect, Moench said, as cumulative exposure to harmful chemicals in the air and water builds each year.

He compared the compounding effect of toxic releases to that of regulated substances. A glass of wine might be safe on its own, just like a shot of Jack Daniels or a few Tylenol pills. But when you ingest them all together, they can be deadly.

“A supposedly acceptable level of lead combined with an acceptable level of mercury combined with an acceptable level of cadmium,” he continued, “is not acceptable. Not that it ever was.”

Utah has fourth most toxic chemical releases of any state

(Francisco Kjolseth | The Salt Lake Tribune) The Kennecott Garfield Smelter Stack is pictured during inversion conditions on the south side of the Great Salt Lake on Friday, December 29, 2023.

Facilities in certain industries – typically linked to manufacturing, metal mining, electric power generation and hazardous waste treatment – must report how they’re handling certain chemicals. Those reports must include treatment and environmental releases.

The EPA’s Toxic Release Inventory tracks those chemical releases, showing what chemicals facilities use in communities, how those facilities manage waste – including through environmental releases – and whether quantities of chemicals and releases have changed over time.

Based on the most recent TRI report, facilities in Utah released 181.8 million pounds of toxic chemicals into the environment in 2022.

That’s the fourth most of any state behind Texas, Nevada and Alaska.

More than 80% of the toxic chemicals released in Utah came from the Kennecott copper mine and smelter.

The facility with the next-biggest releases was Clean Harbors, a hazardous waste company with 14.35 million pounds at one facility and 3.46 million pounds at another.

The top facility being in the mining industry isn’t unusual, as the EPA explains in a page about why the metal mining sector reports the largest quantities of toxic chemical releases. The federal agency credits that to handling lots of material and waste rock each year.

The “very large” Bingham Canyon Mine has not only copper but also pyrite, said Doug Sims, dean of the School of Science, Engineering and Mathematics at the College of Southern Nevada.

The presence of pyrite, or iron sulfide, creates an acidic environment, Sims said, causing problems with the leaching of other trace metals. The more acidic the environment, he said, the more metals start to leach out – and when things get really acidic, the process also produces lead.

One hundred facilities, including the Kennecott mine and smelter, reported managing and releasing lead and lead compounds as part of their report to the EPA.

Sims has worked on several mine projects in Utah and northern Nevada and researches contaminated sediments, geochemistry and paleohydrology in the Southern Great Basin and the Mojave Desert.

Nevada and Alaska also have high amounts of toxic chemical releases because of mining, though they’re primarily mining for gold and zinc, respectively, instead of copper.

The Beehive State also had the fifth most pounds of toxic chemicals released per square mile, mostly behind smaller states.

Kennecott’s releases also pushed Salt Lake City to the top five in the nation for releases per square mile in metropolitan areas – more than Los Angeles, Detroit, Pittsburgh and Houston.

Though facilities in larger cities reported more waste overall, they were more likely to recover, recycle or treat their waste.

Among the towns with more releases per square mile were Butte-Silver Bow, Montana, where Montana Resources operates an open-pit copper and molybdenum mine, and Juneau, Alaska, where Hecla Mining Company manages the largest silver mine in the country.

And facilities in nearby Elko, Nevada, had more overall disposal and release of toxic chemicals than Salt Lake City, primarily driven by gold mining.

Failures happen but aren’t catastrophic

(Trent Nelson | The Salt Lake Tribune) The Bingham Copper Mine on Wednesday, March 20, 2024.

Though toxic chemicals can cause major damage to the environment and people, the U.S. has “some of the best mine reclamation and management” to prevent that as far as written policies go, Sims said.

“Are they always followed? Most of the time,” he said. “But failures happen.”

If failures do happen, they aren’t likely to be catastrophic — unlike the collapse of an iron-ore tailings dam in Brazil, he said. Sims researched that failure, which killed 272 people, flattened entire villages and caused widespread environmental damage.

But tailings ponds and other methods of containing toxic chemicals can and do have cracks and leaks, Sims said.

Leaks mean water saturated with toxic chemicals leaches into the soil environment and moves downhill through the ground and groundwater, he said – and that can be a big issue if people have wells.

He’s worked with mines in Utah and northern Nevada and said they’re “really run well” and have good environmental and health and safety departments that pay attention to cracks and leaks.

“They haven’t had any bigtime catastrophes,” Sims said, but they do need to make sure they’re monitoring systems correctly.

Part of that includes federal requirements like reporting releases of chemicals in the TRI, which facilities must do for 2023 by July 1, 2024.

Rio Tinto is actively working to reduce releases of TRI-reportable chemicals at the mine and smelter, Champo said.

Efforts include:

  • Expanded application of dust suppressants and road grading to reduce dust emissions.

  • Capture of 99.9% of the sulfur during the smelting process after capital investments.

  • Remediation of historically contaminated soil to specifically sited, engineered and permitted facilities.

  • Larger payload capacity haul trucks with higher efficiency engines to reduce tailpipe emissions.

Megan Banta is The Salt Lake Tribune’s data enterprise reporter, a philanthropically supported position. The Tribune retains control over all editorial decisions.