I just got a lot on the Alabama river that has two drilled artesian wells on it. They are about 10 feet apart. One, the older of the two is a 4" PVC cased well that goes down 450 feet. This well hasn't been used in about five years. The other is another 4 inch casing that goes down 650 feet and flows a lot more water, there is a one hp suction pump on this well that is pretty ragged, but it does work.

I want to change over to submersible pumps on both of the wells, one for a primary and one for a backup. I have a used 1hp Sta rite 3 wire pump for the first installation. I plan on putting the 450 foot well back into service first, before I mess with the deeper well that is working and providing water to the house and to a live bait pond (overflow goes to a pond about 100 feet away). The 450 foot well free flows about 5 GPM at 6" above the ground, the 650 foot well free flows about 8 GPM at 3 feet above the ground.

My questions:
1. If I drop the pump down 40 feet into the artesian well will that be plenty deep to keep the pump wet? The Sta rite pump is a 20 GPM model. This all depends on the capability of the well. Just because it flows doesn't necessarily mean it will pump more water than it flows.

2. I plan on the water pumping through the well seal with 1.25" schedule 80 drop pipe. Is a coupling placed above the seal enough to hold up the pump? The seal is a 4" PVC one-piece seal with a 1.25 line hole in it. Yes a coupling should work fine for holding the pump up. That is if the Sch 80 is threaded. I wouldn't want to trust PVC glue for this job.

3. With the schedule 80 drop pipe, should I do anything special when making the connection between pipes to keep them from coming loose with the pump twisting? I plan on putting a torque arrestor above the pump but am not sure that is enough. Also I plan on using a 1/8 inch stainless steel safety wire to pull (and sink) the pump. I don't put much faith in torque arrestors or safety cable. This is done by amateurs in my opinion. If you can't trust the pipe the pump is hanging on, why would you trust a little 1/4" cable? Just tape the wire at the top of the pump and every ten feet there after and you'll be fine. The torque arrestor is mostly to center the pipe to protect the wire. Black electrical tape does the same thing.

4. The guy who sold me the wire sold me 10-3 pump wire without a ground saying that I didn't need the ground to the pump, it was a waste of copper (this was a culligan manager). Is there any danger in this? The Culligan manager is a moron! The green wire is national code and will help protect your motor in the occurrence of a lightning strike or spike voltage. He also sold you heavier wire than you needed. You can go 250 foot with #14 wire.

5. What is the most efficient type of pressure switch for the pump? There was a "made in china" pressure switch on the shelf in the pump house that looks new and is a 20on 40off switch, there is a 75 gallon bladder tank there too. Recommendations? I sell a made in China pressure switch in place of the Square D FSG-2 and love it. Since Square D has cheapened their switch so much over the years, I find the Chinese one is just as good or better. On the Bladder tank, I recommend Flexcon tanks. If your looking at one in a big box store or hardware, you are likely to be buying a substandard tank.

6. I am trying to figure out if there is iron or just silt in the water, I tested it and it came up blank for just about everything. The pipes have a reddish color material on the walls, but if you rub your finger on it, it comes right off. I thought rust would actually discolor the pipe and not come right off. Is this just red clay silt?
Only a trusty water test will tell the truth on that one. You should be able to get it tested for Iron, Hardness, PH, Manganese and tannon pretty easily. I wouldn't have the Culligan man do it however!
Last one:

The 650 foot well has a overflow pipe about 8" above the ground that free flows water to a small live bait pond. If I install a submersible pump into the casing where there is just a suction pipe now, will enough water still get by the pump to feed this overflow pipe to the pond? Yes

I really appreciate your help with this, I have to do this myself as the nearest (sober) plumber is about 40 miles away.