Open Spaces
4:33 pm
Fri December 6, 2013

Wyoming’s little talked about pollution source: trona mines

Wyoming’s biggest export is soda ash, which comes from trona mines in Sweetwater County. Last year, the trona industry produced 17 million tons of soda ash for which the state received nearly $90 million in various taxes and royalties. But as Wyoming Public Radio’s Irina Zhorov report, the industry has a dirty side, too. 

IRINA ZHOROV: Wyoming is used to superlatives. The biggest coal bed, the largest mine, the most wind! Here’s another:

[VIDEO PLAYING: The silver retreats of Wyoming, USA is home to the largest reserve of trona. ]

ZHOROV: The largest trona deposit. That’s a video from one of the companies that mine trona. Aside from another small mine in California, the four facilities in southwestern Wyoming ARE the trona industry in the U.S.

MARION LOOMIS: We now produce about 90% of all the soda ash used in the United States and about 25% of all the soda ash used in the world. 

ZHOROV: That’s Marion Loomis, Director of the Wyoming Mining Association.

LOOMIS: About 85% of the value of what Wyoming exports out of the United States is soda ash.

ZHOROV: Trona is used to produce sodium carbonate, which is used in everything from glass production, paper, and baking soda. But the industry that produces these innocuous everyday products is also a big polluter. It’s one of the biggest emitters of volatile organic compounds and hazardous air pollutants among big sources in the state. Most of the facilities are also in the top 10 list of emitters for nitrogen oxides.

Bruce Pendery lives in Utah but works for the Wyoming Outdoor Council and has made the drive through the trona patch in Southwest Wyoming on his way to Cheyenne dozens of times…

BRUCE PENDERY: You can see the plumes of smoke stretching out from the various plants and covering really quite a wide area.

ZHOROV: He says the pollution he sees around the trona plants seems worse than the coal fired power plants he also passes.

Pendery’s observations are anecdotal. But on the day of my visit to the FMC trona facility, the horizon was also heavy with dull gray columns. John Lucas is FMC’s environmental team leader and he navigated through the huge industrial site’s many stacks.  

JOHN LUCAS: Basically what you’re seeing is primarily water vapor. About 99% of our emissions here at FMC are water vapor and some carbon dioxide. The other 1% of our emissions are methane from safely venting the mine from naturally occurring methane, and then other process related emissions.  

ZHOROV: Those process related emissions adhere to complicated permitting from the Department of Environmental Quality. DEQ says getting emissions down is a process. Lucas says one way it’s done is the best available control technology, or BACT, review, which is done when they modify or add operations.

LUCAS: They’ll look across the industry and find the best available control technology and that’s what they’ll apply.   

ZHOROV: The idea is that as technology gets better, emissions will get lower. But there may be other holes. 

For example, there are also Maximum Achievable Control Technology, or MACT, standards that the EPA promulgates to control hazardous air pollutants for new and existing sources. But for the most part the EPA never developed any MACT standards for the trona industry.

And remember that methane Lucas mentioned? 

Those industrial sites sit on top of huge mazes of very gassy underground mines. FMC’s Fred von Ahrens says large volumes of air are moved around the mines to vent them of the methane.

FRED VON AHRENS: The real goal of the ventilation in the mines is to move fresh air in and keep fresh breathing air in there for the miners. 

ZHOROV: The Mine Safety and Health Administration requires this. The dirty air carrying methane, volatile organic compounds and hazardous air pollutants gets pumped up to the atmosphere through a vent.

VON AHRENS: The bulk of the VOCs and HAPs come from the shales that are in the mines themselves.

ZHOROV: In other words, those vents contribute pollution. But they’re not controlled.   

Here is the DEQ’s Cole Anderson.

COLE ANDERSON: It’s important to note that [the Air Quality Division] regulates sources essentially from the ground level and up. We do not regulate mines or underground mines.

ZHOROV: In past operating permits for the trona companies, DEQ listed the mine vents as sources of emissions but usually did not list how much they emit or any permits that apply to them. Still VOC and HAP emissions are included in DEQ’s inventory, but methane is not.

Jeremy Nichols, Climate and Energy Program Director for WildEarth Guardians, has been looking at the issue of methane emissions from coal mines. He says there are no specific regulations dealing with methane venting from mines but the permits still strike him as odd.

JEREMY NICHOLS: It seems to me that Wyoming needs to be making sure that these trona mines are starting to report their emissions and ensure that they’re being accounted for through their permits… They have to at least come clean and say ok from our ventilation systems this is how many tons of methane are being released.

ZHOROV: There’s another issue, too. If pollution is being pumped into the atmosphere and things like methane aren’t even accounted for, how do nearby residents know their air is okay?

That’s usually done with monitoring. Cara Keslar works in DEQ’s monitoring division.

CARA KESLAR: The state doesn’t have any monitors at the trona facilities right now.

ZHOROV: That hasn’t been one in Green River within the last 10 years, either. This spring, DEQ did install an ambient air monitor in Rock Springs, about 40 miles downwind of the facilities.

KESLAR: Actually looking at the emissions, we were more concerned about oil and gas growth closer to Rock Springs than trona.

ZHOROV: Data from the monitor does not show any legal exceedances so far, but there have been short term spikes in particulate concentrations. The trona companies have monitors, too, though they only monitor one pollutant: particulates.

If it seems like the trona industry is getting by with less regulations and checks than other industries, Nancy Vehr, who represented the DEQ’s Air Quality Division out of the attorney general’s office for a decade, says that’s an illusion. She says Wyoming has solid regulations.

NANCY VEHR: My understanding is most of the trona being mined in the US is virtually all from Wyoming and there’s only several facilities that are doing it. So that may be why the federal government has not promulgated regulations specific to trona. But that does not mean that trona is going unregulated.

ZHOROV: And FMC’s von Ahrens says if you compare the whole trona industry to the whole oil and gas industry, for example, trona’s emissions are much smaller. Plus, he says, trona’s just different.

VON AHRENS: The trona itself is a very pure mineral…it’s a pretty benign chemical.

ZHOROV: That may be true, but producing that benign chemical can be dirty business. For Wyoming Public Radio, I’m Irina Zhorov.