How can a 20 ft wide power easement become a 120 ft wide easement?

Most of the folks in the direct path are wondering how a normal 20 foot wide power easement can suddenly become a 120 foot easement with no due process?  Although some people have stated this can be done under “eminent domain” – but I wonder if that holds when shorter and probably less expensive and more reliable routes not near any homes are available.  It seems like most of these routes are really just the QUICKEST to create by eliminating the effort to acquire new rights for a shorter and lower cost line.  It seems like running the lines right down Waterfall, Antioch and Thoroughfare are simply to use existing Dominion Power’s Right Of Way.   If anyone has some facts to help us understand please post under comments for this post.