Role of US Magnesium’s bromine emissions in Utah’s PM2.5 mess gets new scrutiny

HB220 directs DEQ to set standards for the halogen chemical that accelerates particulate formation.

(Trent Nelson | The Salt Lake Tribune) US Magnesium's Rowley plant, seen across the Great Salt Lake from Stansbury Island on Saturday, March 26, 2022. The plant is a leading emitter of bromine, an emission that would come under close scrutiny under HB220.

A House committee on Wednesday advanced a bill that would enable state environmental regulators to set standards for bromine, an industrial emission that was recently determined to play a surprisingly outsized role in Utah’s harmful levels of fine particulate pollution, or PM2.5, that build up during winter inversions.

Sponsored by Rep. Andrew Stoddard, D-Sandy, HB220 started out as a comprehensive 65-page bill addressing numerous aspects of Utah’s air quality challenges in a coordinated way. By the time it reached the House Natural Resources, Agriculture and Environment Committee, however, just a single page was left, featuring only a proposal to study bromine.

“A recent study found that bromine pollution was responsible for increasing wintertime inversion pollution by 10 to 25%. What this does is allow [the Utah Divisions of Air Quality] to determine if there are other sources of bromine and work to regulate and reduce those emissions,” Stoddard told the committee. “Utah is really unique with its inversion problem and geography. This bill would allow Utah to get out ahead of the EPA [Environmental Protection Agency] and take it into our own hands.”

To help explain the bill, Stoddard was joined by the study’s lead author Caroline Womack, a University of Colorado Boulder research scientist working at the National Oceanic and Atmospheric Administration, or NOAA.

“We were looking at bromine compounds that are emitted and then because of the nature of their chemical reactivity, contribute to the formation of PM 2.5. So it’s more of an indirect effect,” Womack said.

The bromine emissions largely come from a single source: US Magnesium’s Rowley processing plant on the southwest shore of the Great Salt Lake. The study estimated the plant releases 2.5 million tons of bromine emissions a year.

Bromine compounds are not in and of themselves considered “pollution,” nor are they regulated under the federal Clean Air Act. But their reactivity facilitates the formation of dangerous particulate pollution in the presence of sunlight, according to Womack.

Bromine is among 17 reactive elements known as halogens, a group that includes chlorine which is present in far greater concentrations in the Great Salt Lake and is federally regulated as an air pollutant.

No one from US Magnesium spoke at Wednesday’s committee, but several members of the public came to the microphone to voice support for HB220.

“If there’s anything that we can do to improve the air quality around here, it is absolutely imperative that we do so,” said Ren Griffeth. “Utah suffers quite substantially because of the air quality. Currently, Utah residents have been shown to lose 1.1 to 3.5 years off of their life span as a result of poor air quality. So just take a moment and consider that you’ll lose a year or more of precious time on this planet and with loved ones just because of the air.”

Committee chairman Rep. Steven Lund, R-Manti, noted that bromine compounds themselves are not dangerous to human health and were recorded at extremely small concentrations over the Great Salt Lake.

These levels were just 3 parts per billion near the plant, but that is enough to result in an alarming increase in the amount of fine particulate in the atmosphere, according to the study.

“The levels got lower as they move towards the Wasatch Front because the bromine was undergoing chemical conversion with other things in the atmosphere,” Womack told the committee. “So using our model, we were able to estimate the impact that those bromine emissions would have on the buildup of PM2.5.”

The committee amended the bill to examine all halogens, not just bromine.

“We want a good study of what’s going on in Salt Lake, so that we can understand how this is affecting our air quality,” said Rep. Tim Jimenez, R-Tooele, who insisted on the amendment. “That way, we’re not targeting any one chemical, we’re hitting a group of chemicals within that ‘Group 17′ halogens.”

On a unanimous vote, the committed passed out the bill, which now awaits action on the House floor. The move came as a relief for clean-air advocates who had been championing HB220.

“While we are disappointed to not see the full bill pass through committee, we are encouraged that the committee is taking halogens and specifically bromine seriously I want to better understand it,” said Eliza Cowie, policy director for O2 Utah.