Green’s Dictionary of Slang

sano n.

1. (Aus.) a drinking fountain [? SE sanitary or Lat. sanos, sound].

[Aus]Advertiser (Adelaide) 27 Feb. 11/5: From ‘SANOS’: Several months ago attention was drawn, through ‘The Advertiser,’ to the insanitary public drinking fountains provided in Adelaide and suburbs, under the name of ‘sanitary’ faucets.

2. (Aus., also san(n)o man) a sanitary carter or inspector; a sewage disposal worker [abbr. + -o sfx (3)].

[Aus]Sun (Sydney) 20 Dec. 5/6: The Season’s Greetings from The Sanno Man: When sewers come I know my fate; / No more I’ll come and crash the gate.
[Aus]Kings Cross Whisper (Sydney) lxvi 5/5: Fifty Sydney dunny carts, manned by sano men carrying dozens of cut lunches.
[Aus]F.J. Hardy Outcasts of Foolgarah (1975) 151: The garbage collectors [...] unofficially called Garbos for short; the sanitary carters, officially termed night-soil labourers, unofficially called Sanos for short or less reverently shitties.
[Aus] (ref. to late 19C+) G. Seal Lingo 78: One term whose diminutive has definitely been affectionate, if not downright essential, has been sanitary man, in use since at least the end of the 19th century. Widely lingoised as the sanny or sano man, this fast-disappearing trade is also known as the night man or simply the dunny man who comes to take the nightsoil away.