I have used this system since I moved to East Texas. I live in a rural area and a well is necessary. When I first bought this property and saw this setup I didn't believe it. After asking around I found it very popular in this area. I have been a maintenance supervisor for many years and thought I had seen every thing.
The original system used a holding made out of concrete. This tank had small cracks in it which allowed roots to grow inside the tank. So I purchased a plastic 85 gal tank designed for water well storage. Then I installed a float switch like that used on a sump pump, only this one comes on on low water, which in turn starts my compressor. When the holding tank is full it shuts off and my water pump takes over from there, pumping water to the house on demand as a normal well pump would.
With this system there isn't any sand etc. in the water, it's clear as a bell and tests like bottled water!! (I said TESTS!!) No oder either.
I built an interface relay and switch to enable me to use 220V motors on my pump and compressor.
Want more info go on google.com and enter "Air Lift Pumping"..