[TowerTalk] Screw Anchor Question

[Phil Camera]

Don't take this personally, but IMHO screw anchors are only to be used 
for a temporary installation.
A 70 ft. tower is a sizable structure and needs adequate anchors, 
meaning, anchors that have concrete holding them in place.
Yes, you should be concerned about the anchor in question, as well as 
the others. 
If you get Zero rain, and I mean none, then your anchors may last.  But, 
if your location gets any kind of rain, then that soil can become very 
soupy and won't hold worth squat.
I'd seriously rethink your installation.  Gd Luck and be safe, Phil  KB9CRY