The aforementioned editorial in the Philadelphia Inquirer on hydrofracking mentions that

An EPA study in 2004 deemed the process safe …

But this is not true. One reason why the  EPA concluded the practice could be done safely was that individual states would be monitoring the process using the Underground Injection Control provisions of the Safe Drinking Water Act. But guess what? The Energy Policy Act of 2005 gutted this oversight! I’ve explained this failing of the logic behind passage of this provision of the Energy Policy Act of 2005 in a previous post. I hope this point is kept in mind as these matters unfold.