In the US, fracking has become an established technology for extracting shale gas. The process remains controversial and France has even banned it. But in the US, it's a booming industry.In the American midwest, shale gas platforms are springing up everywhere. The US wants to cut its reliance on gas imports. But the extraction method called fracking is believed to release dangerous chemicals. Many fear it could contaminate drinking water supplies because it's not clear how companies dispose of the waste water. Our reporter Max Hofmann talked to proponents of the technology as well as those potentially at risk.