Wells are naturally occuring and have natural spring water in them. In most wells the makers have dug deep into the ground and struck water. The water, in turn wells up (hence the term well) and...
If anything contaminates the water, it would really not be good to use. It would best if you boiled water you got out of a well you aren't certain about drinking from.
The above contributor...
There are only a couple ways to get air in the water line, coming from the well. The most common is a hole, or leak in a fitting, or the suction line if it is an above ground pump. if it is a...