What is a stand pipe in the street?

I was looking at my local water comp. and found out that on my street is a stand pipe...seems that if people around here do not have running water they can prepay the water comp. and use the pipe to get water...it is like a old water pump, I guess. I am also sure, they use it for things like construction and filling water tanks to keep dust down. I live in Arizona, and it is a law to keep the dust out of the air when working on things that may kick it up.