Kennecott’s Bingham Canyon Mine isn’t just one of Utah’s biggest sources of toxic waste. It’s among the top in the country.

The mine had among the highest number of releases of 90 metal mines that report to the EPA on how they handle toxic waste.

Metal mines handle and dispose of some of the largest quantities of toxic chemicals in the country, and one of the biggest sources is just west of Salt Lake City.

Kennecott’s Bingham Canyon Mine had the third-most releases of 90 mines that report to the U.S. Environmental Protection Agency’s Toxic Release Inventory, or TRI, program in 2022.

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 the latest TRI report.

The Bingham Canyon Mine disposed of or released 132.4 million pounds of substances tracked through the TRI program. That was around 72% of the total releases in Utah.

It was also more than dozens of mines across the country. The only two mines that released more were:

  • Red Dog Operations, one of the world’s largest zinc mines. The mine, located about 105 miles north of the Arctic Circle in northwest Alaska and operated by Canada-based Teck Resources Limited, reported 658.7 million pounds of environmental releases.

  • Goldstrike Mine, an open-pit gold mine near Elko, Nevada. The mine, operated by Nevada Gold Mines, reported 210.6 million pounds of environmental releases.

These three mines and two others — one in Juneau, Alaska, and another close to Goldstrike also operated by Nevada Gold Mines — are the top five facilities in the country for environmental releases.

That 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.

Rio Tinto also pointed to the volume of dirt and rock that Kennecott moves each year.

Those “millions of tons” of dirt and rock have “naturally occurring trace levels of metals” reportable to the federal government, making the facility 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 tailings ponds just north of Magna and east of The Great Saltair.

The mine’s smelter also is a major source of releases, with 19.2 million pounds disposed of or released on- and off-site in 2022.

Among facilities in the “primary metals” category, that’s second only to an open-pit copper mine, smelter and rod mill about 80 miles east of Phoenix. That facility, operated by Freeport-McMoran, released 27.4 million pounds of TRI-reportable chemicals in 2022.

Toxic chemicals can cause major damage to the environment and people, but the United States has “some of the best mine reclamation and management” to prevent that as far as written policies go, said Doug Sims, dean of the School of Science, Engineering and Mathematics at the College of Southern Nevada.

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

Failures can include leaks in tailings ponds and generally are not catastrophic, Sims added.

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

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