Equipment needed to pump 1000 vertical feet at 15 gpm

[Chris Karnaze]

I have a well and need a pumping system. I am not getting much attention from the professionals that I have talked to, so I would like to learn a few things before they do come around. The only thing I know for sure is that I will be using a commerical single phase 10 KW diesel generator to power the pump. The elevation of the well site is about 1400 feet. The well is 850 feet deep (static level is much less, but I want to go the full depth), and I need to go another 100 feet vertically to reach the tank. The hole diameter is 6 inches, the well is rated at 50 GPM, and I need 15 GPM from the well.

What size submersible pump is needed? How is that calculated.
Who makes the best pumps?
Would using a 3 phase pump with a phase converter be better (e.g. wire cost and longevity)?
How is wire size calculated?

Thanks

 

[Valveman]

Even if you set the pump at 850' it is only lifting from the actual water level. And if this is a 50 GPM well and you only need 15 GPM, the water level may not pull down very far. It is important to have the correct head for the pump. So, it is not good to set a pump capable of lifting 800-900 feet when the water level is only 100-200 feet deep. We need the static level of the well and a pumping level at 15 GPM would be great, or we can make a guess.

You have been reading the wrong stuff if you are considering a 3 phase pump and inverter, as those are marketing gimmicks. An inverter might allow for a smaller size wire, but decrease longevity and causes many other problems in the process.

Size is calculated by adding the pumping level to the 100' of lift and the 40/60 pressure needed at the top.

 

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[VAWellDriller]

Ditto for everything said above. Pay someone to do a pump test....even if it costs you 2 or 3k........you will save THOUSANDS and have a longer lasting system with the right information and installing the right equipment for the job.

 

[Chris Karnaze]

Even if you set the pump at 850' it is only lifting from the actual water level. And if this is a 50 GPM well and you only need 15 GPM, the water level may not pull down very far. It is important to have the correct head for the pump. So, it is not good to set a pump capable of lifting 800-900 feet when the water level is only 100-200 feet deep. We need the static level of the well and a pumping level at 15 GPM would be great, or we can make a guess.

You have been reading the wrong stuff if you are considering a 3 phase pump and inverter, as those are marketing gimmicks. An inverter might allow for a smaller size wire, but decrease longevity and causes many other problems in the process.

Size is calculated by adding the pumping level to the 100' of lift and the 40/60 pressure needed at the top.

The static level is 230 feet. A neighbor told me he sets his pumps much deeper than the original static level, because in California we have a lot of drought seasons, and it is a real pain to lower the pump. How does one determine how deep to set the pump based on the static level and the level water was first found.

 

[Chris Karnaze]

Ditto for everything said above. Pay someone to do a pump test....even if it costs you 2 or 3k........you will save THOUSANDS and have a longer lasting system with the right information and installing the right equipment for the job.

Given that there is a 600 foot difference between the static level and the level water was found, and I only want to draw 1/3 of what the well was rated in GPM, what will a pump test reveal?

 

[Valveman]

A pump test would tell you the max pumping level when using 15 GPM. Done in the drought season this would tell you how deep the pump needs to be set. Done in the wet season you will have to guess at the pumping level during a drought.

 

[Chris Karnaze]

A pump test would tell you the max pumping level when using 15 GPM. Done in the drought season this would tell you how deep the pump needs to be set. Done in the wet season you will have to guess at the pumping level during a drought.

Thanks. The static level of 230 feet was determined about 15 months ago when the well was dug, and there has not been much rain since. When the pump is installed, can they determine the new static level (using some other pump perhaps) and use that to determine optimal depth? Or when the pump is being installed, can they do some kind of test (or are the pump testing people different from the pump installing people). I don't understand what 40/60 pressure is and why it is bad to install a bigger pump that is deeper and not ever have to reset the pump (until the well goes dry).

 

[Valveman]

If you buy a large enough pump, plenty of pipe and wire, you can test the well with that pump. But then you have purchased a pump that is probably too large, and more pipe and wire than you needed. So, after you test the well you will need to install a restrictor like a Dole valve, sized to the rate figured in the test, to keep the pump from running the well dry. It is also not good for a pump that is made to lift from 850' to work in a well with a water level of only 230'. It causes the impellers to rise up and wear on the top. The restrictor valve is to put artificial head on the pump, making it think the water level is 850', so the impellers are floating in the right position.

If you pay someone to use their test pump and do this for you, there will be some expense. But then you will be able to set the correct pump at the correct depth. If the pumping level at 15 GPM never gets below say 350' in the dry season, then setting a much smaller pump at 400' would be much less expensive, use less energy, last longer, be easier to work on, etc.

Most people don't do the test. They just set a big pump at the deepest depth and live with the consequences.

40/60 means the pressure switch starts the pump at 40 and off at 60 PSI. 60 PSI is the same as another 138' of depth to the pump. So, to get a pump that can produce from 800' water level, it would also need to produce from 938' to reach the pressure switch shut off point of 60 PSI. If the pumping level is 800' then that is what you need. But you would have to put 200-300 PSI back pressure on the pump with a valve if the pumping level is only 300-500 feet.

 

[Reach4]

The well is 850 feet deep (static level is much less, but I want to go the full depth), and I need to go another 100 feet vertically to reach the tank.

Is this pump's only job to fill that tank? If so, no pressure switch is needed. You control the pump with a float switch.

 

[Chris Karnaze]

Is this pump's only job to fill that tank? If so, no pressure switch is needed. You control the pump with a float switch.

Yes, it will only fill the tank. I'm hoping a float can turn on the generator which will power the pump.

 

[Reach4]

For your investigation and study, read up on "upthrust" on pumps. Sometimes a flow regulator (Dole valve) is used to prevent the pump from pumping too many gpm.

 

[Valveman]

Yes, it will only fill the tank. I'm hoping a float can turn on the generator which will power the pump.

Then set the pump close to the bottom and get a pump that can do 850' of head, install the proper Dole valve to limit upthrust, and crank up the generator when you need it.

 

[VAWellDriller]

You might google USGS Water Science Center....they maintain a network of observation wells to monitor water levels. I drill a lot of these around here...they get a pressure transducer and satellite link and broadcast water levels every day. Information is public and on the internet. If they have any near you, you will get some info on the seasonal water level fluctuation your neighbor spoke of.

What does the local driller recommend?

Where did you come up with the 15GPM requirement? For most residential use, that's a lot of water in a days time, given that you are using storage tank, is that set in stone?

 

[Chris Karnaze]

You might google USGS Water Science Center....they maintain a network of observation wells to monitor water levels. I drill a lot of these around here...they get a pressure transducer and satellite link and broadcast water levels every day. Information is public and on the internet. If they have any near you, you will get some info on the seasonal water level fluctuation your neighbor spoke of.

What does the local driller recommend?

Where did you come up with the 15GPM requirement? For most residential use, that's a lot of water in a days time, given that you are using storage tank, is that set in stone?[/QUOTE

I have asked the driller for a pumping estimate but haven't got it yet. I picked 15 GPM because before I get a tank, I have some framing and irrigation to do and can't k wait a long time for water. Even after getting the tank and after the grading, I'd rather replenish the tank in big gulps. Unless the cost of a bigger pump to get 15 GPM is significant. I have about 20k in the well and maybe another 20k for tank and pumping, so as a percentage of total cost I favor a large pump. We have a lot of fires out here as well.

 

[Chris Karnaze]

Oops. Grading not framing