That’s about 5000 sqfeet, assuming a 4” depth.
70’x70’
I think your math is too optimistic.
14,000 barrels would be a square of 118 barrels by 118 barrels.
A 42 gallon barrel is more than one foot in diameter, and at least 3 feet high.
That would be at least a quarter acre - and three feet deep.
Shakespeare - Macbeth Act 5, scene 1