Where can I dispose of used coolant?

Changed my coolant, but can't figure out how to get rid of the used coolant. Advance Auto Parts wouldn't take it. They suggested Firestone, but when I called, Firestone said they don't take coolant. Still need to check with AutoZone and O'Reilly, but I'm assuming they won't take it either AutoZone told me they don't take coolant, and O'Reilly didn't/never picks up the phone