Recent research from Duke University, in North Carolina USA demonstrating a strong correlation between fracking and contaminated drinking water supplies, see http://sites.nicholas.duke.edu/avnervengosh/duke-study-on-shale-gas-and-fracking/
This research has been peer reviewed and can therefore be deemed to be Indepenedent. The research paper has been published at http://sites.nicholas.duke.edu/avnervengosh/files/2012/12/PNAS_Jacksonetal2013.pdf , and their observation from data gathered from 141 drilling sites is that “Overall, our data suggests that some homeowners living < 1 km from gas wells have drinking water contaminated with stray gases " (sic).