New research seeks to answer key scientific questions about Sublette County ozone

Feb 22, 2013

Drill rigs like this one are one source of emissions that could be contributing to ozone formation in Sublette County.
Credit Willow Belden

Sublette County has an ozone problem. Ozone is produced by emissions from the oil and gas fields and contributes to smog, which can cause health problems.  Several times in the past few years, ozone levels have exceeded federal limits, and the Environmental Protection Agency has given Wyoming three years to fix the problem. The Wyoming Department of Environmental Quality has been working with local residents and industry to come up with a solution. But that’s hard to do, because nobody understands the exact chemistry of ozone formation. Wyoming Public Radio’s Willow Belden reports that research funded by DEQ may finally be close to providing answers.

WILLOW BELDEN: It’s a sunny afternoon in the Pinedale Anticline gas field. Rolling hills of sage brush are dotted with drill rigs, compressor stations, and well heads. Rob Field, an atmospheric scientist from the University of Wyoming, is driving around, collecting data. The back of his SUV is crammed full of fancy machines that measure pollutants in the air. One measures ozone. The others measure methane and nitrous oxides, or NOX, which are ingredients in ozone.

ROB FIELD: We get a measurement every five seconds on the Picarro system that measures methane.

This mobile monitoring system measures methane, nitrous oxides, and ozone.
Credit Willow Belden

And we get a measurement every ten seconds for the NOX measurement and the ozone measurement.

BELDEN: These constant measurements allow Field to create a map of pollution levels in the gas field. At the crest of a hill, we come to a busy gas production area. There’s a drill rig, some well heads, a liquids gathering facility, and a plant that treats fracking wastewater. Field points to his computer screen, which shows methane levels. Until now, the levels have been very low – around 1.8 parts per million.

FIELD: We’re going to watch the methane value, and then we’re going to see if we find any plumes along here. So here’s one.

BELDEN: Oh I see…

FIELD: Just jumped up.

BELDEN: … to three-point-eight. Oh wow, now it’s up to 48.

FIELD: Yeah.

BELDEN: As we drive by other production equipment, we encounter other similar plumes, or spikes in

Rob Field of the University of Wyoming is in charge of the mobile air quality monitoring project in Sublette County.
Credit Willow Belden

pollution levels. Field explains that he’ll be driving this circuit dozens of times, to collect lots of data on pollution, ozone, and weather conditions.

FIELD: So we will look at how meteorology influences the pollution levels. And if we understand that, then the next step is to relate that to when ozone forms: Is there a critical level of pollution accumulation that’s needed before ozone forms?

BELDEN: It seems like a fairly basic question: How much pollution needs to be present before ozone forms? But so far, nobody has an answer to that. They know the basic pollutants, or ingredients, that come together to form ozone, but they don’t know the exact ratio of those ingredients. It’s like knowing that to make bread, you need flour, water, salt and yeast, but not knowing how much of each to use.

John Anderson is a Pinedale resident and served on a task force about the ozone problem. He says the unknowns have made it next to impossible to come up with a solution.

JOHN ANDERSON: One of the things the guys said, very early on in the task force, is, ‘Let’s just get this fixed.’ Well how do you get it fixed? You find out the sources … of the ozone.

BELDEN: And he says to figure out the sources and the chemistry behind ozone formation, you need atmospheric scientists like Rob Field.

The weather is not making Field’s job easy though, because the type of ozone that’s been forming in Wyoming only occurs when there’s a certain amount of snow.

FIELD: The problem with this year is the snowpack is practically nonexistent compared to previous years. So that makes it difficult because I don’t think we’re going to see ozone this year.

BELDEN: If ozone doesn’t form, it’s hard to determine the critical level of pollutants that create ozone – hard to come up with the equation Field is looking for.

But Russ Schnell with the National Oceanic and Atmospheric Administration says that doesn’t mean the study will be a failure.

RUSS SCHNELL: It’s very important to know what doesn’t make ozone, as well as what does make it.

BELDEN: Schnell says he’s optimistic that within a year and a half, Field’s research, coupled with a massive ozone study in Utah, will come up with answers and provide a blueprint for how ozone is formed. Then it’s up to regulators to decide what to do.

SCHNELL: The research will tell you how the ozone is being and what the mixture of the ingredients are. But once you know that, the next question is can you change the ingredients enough to control the ozone? And that’s a question that’s open yet: You know, are we going to shut an oilfield down because the ozone is too high?

BELDEN: Schnell says there will be tough political and social decisions to make, but he says understanding the science behind ozone is a crucial step toward figuring out how to prevent ozone spikes in the future. For Wyoming Public Radio, I’m Willow Belden.