US shale extraction technique under investigation

The US House Energy and Commerce Committee this week launched an investigation into the potential effects of the hydraulic fracturing technique used to extract oil and gas from unconventional sources such as shale deposits.

On February 18, committee chairman representative Henry Waxman and subcommittee chairman representative Edward Markey sent letters to eight oil and gas companies that use hydraulic fracturing to extract oil and natural gas from unconventional sources in the US. 

The committee