When the Ozzies invaded Alaska.

Well I see no one else has any misgivings for making a mockery of the History lesson so I take back any comments of mine inferring I'm sorry.

As for the septic tank; you know there just might be a few old coins worth untold cents buried within. I've read there are actual real people who excavate those things. Although if it was a cistern, it'd just be a bunch of dirty water.