Pollution spikes in Converse County spark concerns over oil and gas expansion

Nov 15, 2013

Energy development in Converse County has led to concerns about air quality.
Credit Willow Belden

Converse County is seeing an increasing amount of energy development, and some residents worry that air quality could suffer as a result. The Wyoming Department of Environmental Quality and researchers from the University of Wyoming are now monitoring air quality in the area.

On the whole, they’ve found that the air is pretty clean. But they’ve also documented times when pollution levels have spiked. Wyoming Public Radio’s Willow Belden reports.

WILLOW BELDEN: The concern that some residents and environmentalists have is that emissions from oil and gas development could lead to unhealthy levels of pollution. That’s happened before, for example around Pinedale. In that area, emissions from the natural gas industry caused a type of pollution called ozone to form – to the point where it violated federal air quality standards. So when oil wells started popping up near residential areas in Converse County, some people got nervous.

CARA KESLAR:  They have concerns about the air quality related to that oil and gas development, so that’s why we decided to place a monitoring trailer there.

BELDEN: Cara Keslar supervises the air quality monitoring program for the Department of Environmental Quality. She says DEQ placed a monitoring station in Converse County last year, to find out how clean the air is, and to make sure any pollution doesn’t exceed legal limits.

The Bureau of Land Management also commissioned an air quality study in the area. They’re expecting applications for more oil and gas drilling on federal land, and they want to use the data they’re collecting to model how air quality might change with increased development. Charis Tours is their air quality specialist.

CHARIS TOURS: We use our analysis … to determine if we authorize further development, is it going to add to that problem? And we certainly can’t authorize anything that’s going to violate an air quality standard.

BELDEN: The researcher who’s conducting the study for the B-L-M is Rob Field. He’s an atmospheric scientist at UW, and he’s done extensive research into the ozone problem around Pinedale. He says so far in Converse County, there’s good news: pollution levels have been relatively low.

ROB FIELD: We’ve not encountered the level of emission plumes that certainly we found in the pinedale anticline project area. … Will that change in the future? That’s the question, and that’s why we’re performing some more of these monitoring circuits and see how the air quality may evolve over time.

BELDEN: There were some instances where pollution levels spiked, though. One day in July, there was a lot of ozone in the air. And for a few days in August, there were high concentrations of carbon monoxide.

Kristi Mogen lives near Douglas. She says her family certainly noticed the pollution.

KRISTI MOGEN: It was just really hard to breathe, and we were kind of thinking, ‘Did we catch a cold or something?’ … It was just very hard to breathe. … We’ve lived out there since 2004. We haven’t ever felt like we couldn’t breathe the air.

BELDEN: Nobody knows whether those pollution episodes had anything to do with the oil and gas industry. And the data that DEQ has collected this year does not indicate that federal air quality standards have been violated. One ozone episode does not constitute a violation. And this one wasn’t specific to Converse County. High ozone levels were reported in Casper, Cheyenne, and parts of Colorado around the same time. So Cara Keslar with DEQ says residents shouldn’t be alarmed.

KESLAR: No, I don’t think we need to be concerned about violating the ozone standard at this point in time.

BELDEN: But just because air quality standards are ok now doesn’t mean there couldn’t be a problem in the future, given that more energy development is expected. Rob Field says he found that the baseline levels of ozone in the area – in other words, the levels of ozone that are present pretty much all the time – were relatively high.

FIELD: So you don’t have to add very much ozone to breach a standard level.

BELDEN: In other words, if industry comes in, drills more wells, and creates just a little bit more ozone, it’s possible that it could push the area over the legal limit.

But we may not know if that happens. That’s because it takes three years of data to determine if there’s an ozone exceedence, and DEQ may not leave its monitoring station in Converse County that long. Again, DEQ’s Cara Keslar.

CARA KESLAR: It’s pretty likely that it would move somewhere else after a year, because we do have other areas that also need investigation. … We’ve never had a case where we’ve left a trailer there long-term just based on that first year of data.

BELDEN: Environmental groups say that’s a problem. They feel it’s crucial to continue monitoring in an area like this – where energy development is on the rise – and to analyze the data carefully when permitting new development. Jill Morrison with the Powder River Basin Resource Council says she doesn’t want Converse County to become another Pinedale.

JILL MORRISON:The Green River Basin is in a nonattainment status. And that’s as a result of natural gas development.  We know, given the recent monitoring in the Powder River Basin and around Douglas – we see the ozone values approaching the standard, and we know there’s a lot more coming. It’s just going to be so important for us to get out in front of this right now and do as much as we can to limit those emissions.

BELDEN: DEQ will complete its initial year of monitoring in December. After that, they’ll decide whether to leave their monitoring station in Converse County.

For Wyoming Public Radio, I’m Willow Belden.