Modern wells for domestic use are created by drilling a hole in the ground that may be 8" to 12" in diameter and 50 to 100's of feet deep.  An auger is put on a shaft and extensions are continuously added to the shaft to mvoe the auger further into the ground.  Once water is  found a pipe, typically pvc these days, that is 6 or 8" in diameater is put down that hole to create a "casing" for the well. That prevents the rocks and dirt from collapsing into the hole drilled.  You could think of that as a "sleeve" as well. Then inside that casing pipe another pvc pipe is inserted. It might be 1" to  2" in diamater. It  hangs down to below the water line, whereever that is, with a pump attached to the bottom of the pipe and corresponding wire that runs down next to the pipe. (the pump is attached to the first segment of pipe and it goes into the casing first and then more pipe is added to the top to drop it further and further down).  When elecrtricity is applied to the pump, water is pumped up the pipe and it goes into one of several types of holding tankes, then a pressumer pump may be invlved in pumping it with pressuer into a home or other building.   It's a fairly simple system. 

Well Components:

1. Casing - A large tube  inserted into the ground to hold the dirt and rock walls of a newly drilled hole back

2. Well Pipe - the pipe that goes inside the casing to pump water up

3. Well Pump - the electrical pump at the bottom of the pipe that pumps water on demand

4. Holding tanks -  places where water is  pumped to for storage and/or pressurization. 

5. Pressure pumps - small pumps about the size of large  shoe boxes that add or create pressure needed to drdive water through pipes and into a home for use
   
   

The water from a well should first be categorized as being for 1) Domestic Use 2) Commercial use and/or 3) Agricultural use.  

Domestic use means "non commercial and non agricultural". Domestic use is thought of as residential use for cleaning, bathing and gardening.  It does NOT include the idea of drinkable(potable) by default. Domestic use is NOT EQUAL TO potable use. that is a separate designation that would supplement Domestic Use catgorization. 

Commercial use would be for use in factories and business. 

Agricultural use is for commercial farming (your private garden is not agriculatural use). 

Water quality wants and needs vary for each of these.  For domestic and commercial use, you might imagine too much lead or iron or other in the water may leave stains on toilets or corrode metal in machines. 

"Potable Water" is a designation given to water that means it meets drinking water standards. Any of the types of water use above could or could not carry an additional designation as being "potable" if the tests for potable water are "acceptable" per state and federal standard that define such a designation. . 

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