DURHAM -- A new Duke University study on fracking blames the water contamination around drilling sites on leaky well shafts, rather than the actual fracking process.

Luis Martinez, with the Natural Resources Defense Council, says, even after reviewing the study, hydraulic fracturing cannot be considered safe.

No, I mean the concerns are not lifted. If you happen to have one of those rails which was contaminated, you are not particularly concerned with whether it happened when they fracked them or when they were producing gas, it's just the fact that you can't use your water anymore."

The deadline for public comment regarding fracking regulations is Monday, September 30th. Comments can be submitted online at NorthCarolinaEnvironmentalPartnership.org.