Seems to be in better condition than in the recent past — there are older pictures here, here and here that show a rusty radiator grill surround. This was probably one of the GGs auctioned off (like this one).
From the Wikipedia article: 'The Green Goddess machines were not primarily fire engines (AFS members referred to them as 'appliances'); they are more correctly titled "self propelled pumps", some two-wheel drive (2x4), and others in four-wheel drive (4x4) form. Their main role was to pump huge quantities of water, from lakes, rivers, canals and other sources, into cities hit by a nuclear attack. [...] Fire fighting was a secondary role.'