Are there civil engineers that specialize in drug tunnels? ‘Yeah, this baby will be okay for marijuana, but you can’t smuggle cocaine in it. No. No. No.’
I think it’s a zoning thing.
Different approval authority means the inspection for a marijuana smuggling tunnel doesn't grant approval for smuggling cocaine.
I’m a civil (structural) engineer. Cocaine would be easy. With say a 4 inch pipe I’d think you could introduce water and pump the cocaine over 900 feet as a slurry. Dewater it and repackage it on the far side.
Pumping cash back, significantly more challenging though.