I have a situation where the electrical service is coming into the Main Panel of a facility where the Neutral, Safety Ground, and Earth Ground are all bonded together. So far so good... However, there is a branch circuit feeding out from the main approximately 100 yards to an outbuilding. While the Neutral and Grounds are not bonded there, the power user has established a separate Earth Ground reference at the outbuilding where he has connected the Ground conductors from Surge Suppressors to the separate Earth Ground. The two Earth Grounds are not bonded together. I know that I have a potentially serious Ground Loop issue here. So, while it is obvious this is not a true single point Grounding configuration, My question is; Does this particular Earth Ground configuration violate NEC?