As New York's environmental review of high-volume hydraulic fracturing progresses, there are still unanswered questions about what happens to the waste water from drilling. It's unclear whether state municipal water treatment plants would be able to handle heavily contaminated fracking waste.

That's why a recent article on Mother Jones' website caught my attention. It points out that in Pennsylvania, where the bulk of the fracking is taking place, most of the waste water is sent to Ohio for disposal. Citing an Akron Beacon Journal article, it says that in 2011, 35 percent of the waste water — about 7 million barrels — from Pennsylvania was sent to Ohio to be disposed of in underground injection wells.

New York's proposed regulations stipulate that any driller who wants to use high-volume hydraulic fracturing in a shale formation would have to have a DEC-approved waste water disposal plan. But the acceptable disposal options are unclear. (This ProPublica article on injection wells says that large disposal wells have been "deemed unsafe" in New York and Pennsylvania.)