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
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
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