Pennyroyal Blue Springs Resort is in Hopkinsville, a town of roughly around 33,000. A lot of regional training takes place there; instructors bring students from a large drawing area.
I suspect the private quarry Bert Stevens mentioned is leased by a private PADI instructor, Marcos Tramell, and
here's a ScubaNashville Facebook Page Link - I have no idea whether that's of any use to you, but if you're curious, there it is.
Bert Stevens, since your listed location is Lebanon, TN, let me ask you about an option in that area I've never been to; Martha's Quarry. Any idea what the status on that it at present? Do people train there these days? Judging from the comments under
the DiveBuddy.com entry, looks like it may no longer be an option?
Some Googling turned up
Loch Low-Minn Diving Resort in Athens, TN. Looks farther from you than Pennyroyal Blue Springs Resort, but might be of interest.
Another long distance place, still in TN, is
Philadelphia Quarry in Philadelphia, TN. Only 3 acres in size. If you teach any students from that area, might be worth knowing it's there.
If you do much Googling and find old references to Dive Cerulean in Cadiz, KY, that one closed years ago.
Richard.