I carry small metal tent pegs to insert in the ground, they are cheap enough to leave if I can not pull them out, granted not the best but there is a path to ground with some water around the peg
Trick I learned long ago - leverage - wrap a small chain around the grounding rod - could be rebar or other length of rod - it may not work on an 8 foot length but will work on smooth rod up to 4 feet maybe - then wrap the other end of chain around some kind of stiff pry bar - 2x4 will work - things can be figured out if someone has tools - maintenance guys might have something - I have pulled some pretty serious stuff out of the ground with a couple feet of chain and a 2x4 - just takes a couple inches to get it started - keep in mind wet ground is better ground.
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