Wow -- if that's true, that's not good! Hope they can figure out a way to keep the GC accessible and safe without restricting access or encroaching on that incredible view. Perhaps limiting exposure to a certain amount of time, not more than once a year or so (similar to when you need to get x-rays taken) might solve the problem.
An alternative: Try visiting Sedona, AZ instead. It's about an hour south of Flagstaff, it's radiation-free (as far as we know), and the red rocks are absolutely incredible!
EDIT: Whoops... didn't read all the way through so I missed the 5-gallon container part. Those particular containers / buckets are not on my list!