Pennsylvania groundwater holding own against drilling boom, studies find

I wonder why someone would down vote this? Curious. I mean it's just a study ... you can agree with it, or have reservations, but why negative ... sometimes these forums confuse me.

“Overall the data demonstrate that there is certainly not a crisis around ground water contamination and unconventional oil and gas activity. That is good news,” he said via email. “However, it does document some contamination. Is ‘rare' contamination around a few percent of wells acceptable? That is a policy question.”