I don't think you actually need ground water, although I think if you DO have ground-water, the heat exchange efficiency is a little better. Also, as I recall, you don't need to get that deep, I think 2-3 feet is sufficient. There are two styles---straight down (i.e. drill a well and drop a loop of pipe down and fill in), or dig a serpentine trench 2-3 feet deep and of a length to hold the suggested loop size. Obviously, the one you choose will depend on your sub-soil conditions.
I'm sure you have found out that there is LOTS of info available on the subject.