rmedgar,
Don't appologize. Your question is a good one. However, I am not a well expert, so I can only speak from my experience. For my situation I knew that water wasn't too far down because my house has a shallow well and when I dug my pond I hit water at 16ft. I used a garden hose and stuck it down the pipe (similar to an oil dip stick)to determine when I hit water. As for the nipple, the pipe sections are threaded on each end. The drive point has female threads which you thread your first section into. Normally, people will use what is called a "drive cap". It is a heavy duty cap that threads onto the pipe to protect the threads while you drive it. However, what I did is connect the "drive coupler" which connects each section the the previous section, then I add a short section of pipe (maybe 6"). This is my sacrificial nipple. The jack hammer bit slips down into the pipe and has a waited collar which causes the nipple to "mushroom" a bit. You drive the pipe down 5ft at a time, then unscrew the sacrificial nipple, thread on a new 5ft section onto the coupler and repeat the process. When I hit water I made sure it filled the bottom few feet of the pipe. Once I was down far enough I took my hose and flushed out the pipe by running it up and down to force out the muddy, sandy water. As I understand it most of these "shallow well" pumps are designed to pump from 25ft or less. You could probably talk to your local health department about where your water table would be at your place. I hope this helps.
