Green’s Dictionary of Slang

(Aus.) municipal sewage disposal workers.

1971

F.J. Hardy Outcasts of Foolgarah (1975) 145: Use tactics, offer to go back to work again, the shitties go back if the Garbos can’t. [Ibid.] 151: the sanitary carters, officially termed night-soil labourers, unofficially called Sanos for short or less reverently shitties.