Hydraulic fracturing, a process known as fracking, is a controversial way to get at natural gas trapped in shale rock a couple of miles underground.
Cleaner than coal, it is being hailed by some as the latest energy solution. But some people who live near drill sites claim the process has contaminated their water supply with methane.
Newsnight's Science editor Susan Watts reports.
Broadcast on Thursday 2 December 2010.