An Insurance industry blog by Jared Wade. Strange Disasters includes a story about a crater in Turkmenistan caused by scientific laissez-faire about natural gas extraction.

...the relatively new drilling method — known as high-volume horizontal hydraulic fracturing, or hydrofracking — carries significant environmental risks.

The bromides themselves are not a public health risk - they account for a tiny part of the salty dissolved solids that create an unpleasant taste in water at elevated levels.  ...But bromides react with the chlorine disinfectants used by drinking water to form brominated trihalomethanes (THMs), a volatile organic compound.