Left-Field Wp&Y Thread

After reading the snow battle summary, it brought to mind something I posted previously, but never got an answer to: That of the facilities....
It was stated several times that the temperature was 30 below.
At those temperatures, how do you keep tanks and pipelines from freezing? How deep do you have to dig trenches for feeder lines, do tanks have an overflow where water can basically come in, fill the tank and if not used, just be allowed to run out?
In a previous post several months ago, I had asked something similar to this about the C&TS just as a question aobut maintainence...is there any regular tank maintainence, pipeline replacement, box cleanout....that kind of thing...Most pipes were cast iron at that time... they should be at about the end of their useful life shouldn't they?
Just a couple of weird questions from left field.
Thanks