I have done a great number of environmental projects associated with the military. I can tell you without hesitation that the greatest environmental
criminals on the planet is the US military. There are numerous military bases in the US that easily qualify as Superfund sites, but because they are
federal property, will never be listed as such.
You dont say what the nature of this base was (army, airforce, heavy armor, air strip, ect), or its age. However, I have think of literally hundreds
of environmental nightmares on most US bases that would require the kind of excavations that you describe.
The poles/markers you mention, are they inert (IE, just plastic poles) or do they look to have any kind of equipment attached?

