The Earthquake in Salt Lake City Caused the Release of a Plume of Hydrochloric Acid

Communities dodged a bullet when winds drove an acid plume of hydrochloric acid that was created by today's Salt Lake City earthquake out over the Great Salt Lake.
Marcia Wendorf

On March 18, 2020, a little after 7:00 a.m., a 5.7-magnitude earthquake struck just southwest of Salt Lake City, in the township of Magna. The nearby Salt Lake City airport closed until the runways could be inspected, and flights into the airport were diverted.

Flights out of the airport were delayed, and the airport concourses were evacuated. The statue of the Angel Moroni that sits atop the iconic Salt Lake Temple of The Church of Jesus Christ of Latter-day Saints lost its trumpet, and a number of buildings lost their brick facades.

Statue atop the Salt Lake City Temple

The statue atop the Salt Lake City Temple, Source: MTPICHON/Wikimedia Commons

All across the Salt Lake area, water and gas lines were interrupted, and people living closest to the epicenter of the quake experienced things falling off walls, and the contents of cupboards being thrown to the floor.

An acid plume

Just west of Salt Lake City, running alongside Utah State Route 201, lies the refinery for the Kennecott Utah Copper, a division of Rio Tinto Group. In a 20,000 square foot, three-story warehouse, the earthquake caused a spill of hydrochloric acid. An acid plume soon formed and, as luck would have it, the wind was blowing south south-west. That pushed the plume out over the Great Salt Lake, and away from populated areas.

According to Jared Mendenhall of the Utah Department of Environmental Quality, the creation of the plume kicked off a full hazardous materials (hazmat) response. Teams from eight state and local agencies responded, with responders donning type-A hazmat suits. These suits are fully encapsulated and include respirators.

Also called to respond was the 85th Civil Support Team of the Utah National Guard. Wade Mathews of the Utah Division of Emergency Management said that "It is my understanding that through the assessment, it [the plume] was blowing away from populated areas, and there was a limited supply that ran itself out." Mathews also said that, "The risk to the neighboring community has subsided."

Concentrated hydrochloric acid, also known as fuming hydrochloric acid, naturally forms acidic mists, like today's plume. According to Wikipedia, the "mist has a corrosive effect on human tissue, with the potential to damage respiratory organs, eyes, skin, and intestines irreversibly." If the mist mixes with common oxidizing chemicals, such as bleach, the toxic gas chlorine is produced.

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The Environmental Protection Agency rates and regulates hydrochloric acid as a toxic substance.

Matthew McFarland, Unified Fire Authority spokesman, told IE that, "Emergency responders are coordinating and assessing, and doing their best to restore things to normal and to continue our efforts against Covid-19 at the same time."

According to McFarland, the warehouse where the spill took place also houses a number of other substances,  and that Kennecott is "well aware of what they have out there." At present, detectors are monitoring the air.

In an email to IE, Kennecott spokesman Kyle Bennett said that, "As a precaution, all operations have been temporarily halted. Across our operations, we are completing the necessary inspections to safely restart." Bennett also confirmed that "State Road 201 has been temporarily closed while we complete an inspection of the tailings facility."

Also closed was State Route 202, and for a time, authorities considered closing I-80, which is a major east-west link across the U.S.