[driftdiver]

I don’t think I can build one here in Florida. The water table is about 2 feet down but thats not too cold. The aquifer certain has a lot of cold water, 72 degrees but I’m pretty sure the state frowns on a bunch of people drilling into it.

[Eric in the Ozarks]

As posted earlier, your loops don't have to be vertical. They can be in a trench or even a pond.