BUR #20600 has been approved by @nonamethanks.
create alias landfill -> junkyard
create alias scrapyard -> junkyard
create alias wrecking_yard -> junkyard
As the title states. Although there is a real-world difference between a junkyard/scrapyard and a landfill, the former being used for breaking down and recycling old vehicles and the latter being used as a general dumping ground for garbage, it seems that for tagging purposes, nobody cares about that distinction. There are plenty of images tagged junkyard which are landfills, no vehicles to be found. It's probably not a distinction most artists care about either, and so there are plenty of vague images where vehicles are present alongside lots of miscellaneous trash (see images like post #4547679).
All that to say that aliasing the two together would probably be fine. I also threw in the non-American English term (edit: terms) as a utility alias. This BUR is in part a test to see if anyone cares enough about the distinction. If it fails, I'll garden the two tags properly.
Updated