ROBERT SIEGEL, HOST:
We hear a lot about the environmental impacts of the energy industry - everything from oil spills and groundwater contamination to smog. Well, there's one pollution we don't hear much about. It's also the most easily reversed. Here's Prairie Public Radio's Emily Guerin.
KENT FRIESEN: Wow.
EMILY GUERIN, BYLINE: Kent Friesen is standing in a dark field in the North Dakota Badlands peering into a huge telescope.
K. FRIESEN: You've got to see this.
LAURA FRIESEN: OK.
GUERIN: The Andromeda Galaxy is framed in the viewfinder. He calls for his wife, Laura.
L. FRIESEN: Wow.
GUERIN: They're from Denver and are rarely in places as dark as Theodore Roosevelt National Park, which is holding a stargazing festival this fall weekend.
K. FRIESEN: I can easily look up and there's the Milky Way. That's so easy to see. And you can't see that in Denver.
GUERIN: If you live in a city, the night sky in western North Dakota will blow your mind. The stars are bright, and there are so many more that you can see. But astronomy buff Jay Bjerke notices something's missing.
JAY BJERKE: Over there.
GUERIN: He points at a butte that's silhouetted by a soft glow.
BJERKE: You can't see stars between the horizon and 20 degrees up. That's the oil fields.
GUERIN: Half a dozen natural gas flares are blazing just outside the park fence. Park ranger Jeff Zylland knows because he spent many nights this summer driving gravel roads in the dark trying to find the sources of light pollution.
JEFF ZYLLAND: Yeah, there's light coming out from the flares, but there's all of these trucking facilities and gas stations and even cities that are just growing.
GUERIN: The National Park Service actually measures light pollution with a special camera. It found that between 2010 and 2013, light pollution in the park's north unit increased by 500 percent - faster than at any other national park in the country.
EILEEN ANDES: It's really hard to get in front of something that is moving that fast and that's that big.
GUERIN: Park ranger Eileen Andes says they've been in triage mode here since the oil boom began. They're just now getting to light pollution. But things are further along at another site where oil fields threaten the night sky, the University of Texas McDonald Observatory.
BILL WREN: Our goal is nothing short of changing the way the oil and gas industry lights their nighttime activities.
GUERIN: Bill Wren is on a mission to keep West Texas dark. His colleagues are already straining to see faint light from distant stars.
WREN: And yeah, if the sky gets brighter than the faint source we're trying to see then it's lost.
GUERIN: When oil and gas development in the nearby Permian Basin took off a few years ago, Wren got worried and looked into enforcing some of the existing lighting ordinances passed decades ago to protect the observatory.
WREN: I've had one person in the industry comment to me that if you start writing tickets, we're going to aim lights up in the sky just to piss you off.
GUERIN: So Wren changed his approach, instead reaching out to some of the oil men to explain the problem. Most of them had never thought about lighting before.
STACY LOCKE: Not at all.
GUERIN: Stacy Locke is the CEO of Pioneer Energy Services. He's also a man with a soft spot for the starry West Texas sky.
LOCKE: You know, it's just one of the great assets of that area. You just have dark skies. You can see stars from horizon to horizon.
GUERIN: He wanted to help, and the fixes were pretty simple - point lights down, not up, and switch to warmer-colored bulbs. Together, Locke and Wren have written a paper about best practices. Stacy Locke says the key is getting the companies that own the well sites on board.
LOCKE: They hire all of the service providers so they can mandate that, hey, if you want to work for me, your equipment has to be dark sky-compliant.
GUERIN: As all this is happening, oil field light pollution may be decreasing for now because there's been a major slowdown in drilling activity, and that means fewer lights blocking out the stars.
For NPR News, I'm Emily Guerin.
SIEGEL: And that story came to us from Inside Energy. It's a public media collaboration that focuses on America's energy issues.
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