Most food manufacturers I have spoken with so far in Nashville already have a service that helps them out with this and I am beginning to think that folks around here don't typically set up rain barrel watering systems for their gardens...
Since I hate paying for water AND taxes, I aim to get most of my yard water from the skies for free.
One source I have found, where you can find them used for $10 each is:
They are currently out of stock. Sigh.
LATE BREAKING NEWS
Coca Cola has them:
Ana is at extension 486 and they are only available Thursday mornings. She recommends that you call Wednesday to verify that they have barrels for sale that week.