On today's Environment Report, I asked Lustgarten: how much do we know about the environmental impact of fracking?
"We don't know as much as scientists say they'd like to know, and we know a lot more than we did four or five years ago when this issue first came on the national stage. There's basically very little monitoring of underground water quality across the United States to check for contaminants, whether that's from natural gas drilling or any other industrial process. Without monitoring and long-term monitoring, there's very little way to know for sure whether fracking chemicals are contaminating water or moving substantially underground," he says.
Lustgarten says there have been quite a few studies lately of the impacts of drilling chemicals and air quality emissions above ground.
"Those studies have found, for example, that there's a correlation between methane and drinking water wells close to places where drilling has happened. There's been several studies published by the Proceedings of the Natural Academy of Sciences to that effect. So this is part of an emerging view that there is a substantial threat. But I don't think with these sorts of scientific studies that you have a consensus until you have many of them and there still are not quite enough. So I think the scientific community is in a state of: concern, but wait and see. But we certainly know a lot more than we did four or five years ago and the signs point to cause for concern."