Wells are essentially free. They used to dig them by hand...you still can, in fact. They're one of the most commonly used pre-technological age way of getting water with the exception of simply living next to a freshwater source.

You don't need metal, you don't need electrical, you don't need pumps, you don't need anything except some rocks, clay, and something to dredge water up with.

It's wonderful how in most places on this earth you can simply...dig...and get water.

I'd call that about as free as something could ever be achieved, gets.