A presentation prepared in 2010 for then-EPA Administrator Lisa P. Jackson made clear that a pre-emptive veto "had never been done before in the history" of the Clean Water Act and could risk litigation. (Associated Press)

Photo by: Alex Brandon

A presentation prepared in 2010 for then-EPA Administrator Lisa P. Jackson made clear that a pre-emptive veto "had never been done before in the history" of the Clean Water Act and could risk litigation. (Associated Press)