Get a used sea-land cargo container. Standard size is like 10 feet wide by7 feet high, by 40 or 45 feet long. All steel, wooden floor, dirt tight. Cost about $2000.00 to $3000.00, they will deliver them. Rent a good sized track hoe. (they will deliver that too) about $400.00 a day. Dig big hole. Lower container into hole. (with chains and track hoe) Cover with dirt. spread left over dirt around, call to have track hoe picked up, light a fat one.
Of course there would be some prep work before covering with dirt. What with an access hatch and vents and elect. wires and water lines and propane lines and such. Put most of the grow op stuff in before you bury it, easier than bringing it down the hatch later. You could even set most of it up inside while it's sitting on top of the ground. (just a suggestion)
This is my dream, this will happen, someday.