I found some on craigslist at a place located on Harry Hines. They were used to store liquid fragrances for incense and such. Washed them out with water and bleach and now use them to store my water for the camper, but I don't drink the water. He advertises $20 a barrel, but I talked him down to $15 since I bought 3. I'm not sure if that was cheap, but it worked for me.
Walk the night, travel light, cross the Rio Grande
Someone strums a mandolin, soft gulf breezes blow
My new life is waiting in old Mexico
-Robert Earl Keen