Maintenance is not high on the list of things to do with Thai's, the chances of them street machines getting clean are slim to none, along my usual route around my area there is a few, I have never seen a one of them being cleaned, plus they are connected to the city water from what I can see, if not then they would be connected to a well pump, god forbid if they are some of the ground water here is terrible,
We now have 2 Makro's in the area I buy their brand of bottle water, I don't even know how much is it's that cheap,