Am new to the forum and life living with a well.

Am about to pull the trigger on buying a 5 acre bit of land out in Arizona. Its out in the desert but has a house and other bits from a previous owner, but no one has really lived in the place for a long time. We believe that the last time the pump and well was really used was a minimum of 4 years ago, and could be as long as 6-8 years.

Someone put a well on the property a while back and am guessing that its about 10 years old. The seller is related to the person who had the well done and tells us that its about 900 feet deep and that they have water in the aquifier from the 400 foot level on down. We have talked with the next door neighbor and their well is at 890 feet, so this sounds correct. The pump is at the bottom of the well and its a 220v version hooked up to a Pumptec Plus controller, then to the generator. No idea on the make of pump, pressure or GPM rating.

There is no power out in this area so we brought a big diesel generator out and did some preventative maintenance on the wiring and switches (all the connections were not real tight and so on) before giving the pump a try. The pump worked fine right off and started at 8.5 GPM, pumping water into a 2500 gallon cylindrical water tank that is situated about 30 feet above us on a nearby hill. We pumped for 90 minutes and then realized that it had stopped pumping, and are assuming that the Pumptec shut the unit off.

Let it sit during lunch plus a bit (about two hours in total) then fired it back up to check things out. The pump worked fine right off but flow was not up to what it was at first, pumping only about 6 GPM. We let it run for about an hour then shut things down. The water tank was about 45% full, or 1200 gallons. Not bad for 2.5 hours of pumping. Water is clean, smells fine and may be ok to drink but we are planning on getting a sample checked just in case.

My question is, does anyone have any idea why it would pump at 8.5 GPM upon start-up, then go back down to 6 GPM after sitting for a while? Talking with the neighbor, he has not had any issues like this and has let his pump run for hours, while another neighbor across the road had had this happen but after several hours of pumping.

Just got a call today from a friend who is out there on the land and this morning he fired the generator up and the pump started right off at 9.5 GPM and after an hours pumping the tank is 3/4's full.

Couple of concerns here are that out in the middle of no-where, water in the desert is life and costly. If we have to drill a new well its going to cost around $15k, and simply replacing a pump is not cheap either as I believe its on the bottom of the 900 foot well. I say "I believe" as I work on airplanes and know anything about wells! If the pump and or well is having problems then the purchase price on the place will do down quite a bit, so trying to troubleshoot things before everything is a done deal. Would appreciate anyone's ideas and suggestions on this.