New well advice needed

Hi all, I have owned a 40 space trailer park since 1978. My 50 foot deep well got a bad Nitrate report and the Health Department has ordered me to drill a new well. Due to the area and Health department regulations, I will have to drill between 400' and 700' to get to "good" water (the area is on top of some pre-historic lake bed and I have to get to the rock under it). A driller familiar with the area, tells me that even though we may have to go 600' the water most likely will come up the casing to within 30 feet of the surface and because of this I only need to set my pump down about 250 feet.
I am looking at a 3hp Grundfos pump to get about 30 GPM. From some of the stuff I have read, PVC drop pipe is not recommended for submersible pumps over 2hp?
My new well will be about 200 feet from my old well, where all my pressure tanks are currently hooked in.
I have read that I should have a pressure tank close to the new well head. Some of my tanks are too big to move (6500#'s empty).
My questions are:
What diameter drop pipe should I use and Galvanized or PVC? (If PVC will work, what diameter and schedule?)
IF I re-locate 1 or more pressure tanks next to the new well, what capacity in pressure tanks do I need adjacent to the well, knowing that I will have 5000 gallons in tank capacity pressure storage 200 ' away hooked to the system?
Would there be any advantage going with #8 down wire instead of #10?
From what I have read here, I do not want to ad any additional check valves.
I welcome any and all advice and recomendation's.
I want to do it right the first time.
Thanks: Bob

Your tanks are fine where they are. I don't know where you got that they need to be closer. What if your pump was set 200 feet deeper? Where would you put the tanks then?

I would set a 3HP, 30 GPM pump on 1 ¼” sch 80 or 120 threaded PVC, although some people would prefer galvanized pipe. And Galv pipe will probably be better if you let that tank waterlog, which rapid cycles the pump.

A 5000 gallon pressure tank only holds about 500 gallons of water. And that is only if you maintain the correct amount of air charge in the tank. You must have a bleeder orifice in the well, a micronizer, or an air compressor for the tank to maintain the proper air level.

The pressure tank doesn’t have to be close to the well, but the pressure switch has to stay close to the pressure tank.

I thought California made you keep a 2500 or 5000 gallon storage tank for fire protection? As I said that 5000 gallon pressure tank only holds about 500 gallons of water. Either way I would have used a Cycle Stop Valve and about an 80 gallon size bladder pressure tank instead. The only reason to use a large pressure tank is because the government agencies that regulate these systems are at least 20 years behind on the beneficial technology that is available.

Even if you set the pump at 250’, I would use 300’ of #10 wire, as that would give you a reduced voltage soft start for the motor. With an old style pressure tank system, a soft start would be helpful.