Yes, the obvious issue is metal equipment that is not adequately (locally) grounded.
The cause of the voltage could be various things, but a faulty mains earthing system
is one possibility that is life-threatening so get an electrician to check that first.
Humans typically live in a dry environment and wear shoes/boots, so we wouldn't
notice a few volts between local ground and mains earth wire.
You want to eliminate the issue, not just measure it? A multimeter on AC-volts
can measure it if you ground one probe, that's easy.
You need an closeby earthing spike driven into the ground (keep it watered in dry weather),
connect external metalwork and metal water pipes to the spikes (lookup local wiring
regulations or talk to an electrician first though).
Also avoid any equipment that isn't properly earthed. In a harsh environment
regular electrical safety checks are obviously necessary...