Drive point well question

[sucker dave]

I’m having a problem with my deep well jet pump on a driven 2” well.
My setup.
Well depth 31’
Driven point gauze size 80
Pump: Goulds j+7. ¾ hp deep well jet with 2” packer.
20 gallon holding tank

Here’s my problem. When I first installed the pump on my system, I had great water pressure. After a couple of weeks I noticed that while pumping, the water would start and stop flowing. Almost as if I was running out of water. I have a second driven well close by allowing me to check the water level. The level appears ok. Is it possible that I’m over driving my drive point? Pumping water faster that It’s returning to the stand pipe?

Thanks!

[speedbump]

You can't pull the water from the well any faster than the screen will let it in. It's all under a vacuum. So if it's surging like that, I would guess the well is barely making water at all.

You could have driven the screen too far. How do you test for water as you are driving the well? You should be checking it every 5 feet with a pitcher pump if the water level is less than 25 feet which I would think it is with a 31' deep well.

What made you go with a deep well jet pump and ejector anyway?

bob...

[sucker dave]

Yea, I did check it as I drove it down. ( however It was my first time doing it)

The reason I went with a deep well pump is, I have a 1.5 dia well about 3 feet away that with a 1/2 hp pump only produces around 2-3 gallons/min. ( although I never ran short of water or had any surging problems). In researching wells, I found that 25' is the max recommended depth for a shallow well pump. Anything deeper requires a packer and a jet pump to get any amount of gpm.

Is there a better way for me to go?

Can you relate the Gauze size to GPM for me? I thought I read somewhere that an 80 gauze equated to around 15 GPM. In which case my ¾ hp pump would be pretty much maxing out the screen.

Because of my other pump not having any surging issues, do you think a smaller pump would work better? Something pulling around 9-10 gpm?

Sorry for all the questions, I really do appreciate any help I can get!

[speedbump]

Replies are in Red!

Yea, I did check it as I drove it down. ( however It was my first time doing it) Ok, if you checked it, you must have used a Pitcher Pump. If so, the water level had to be less than 25 feet. A shallow well jet pump would have worked much better than a packer jet.

The reason I went with a deep well pump is, I have a 1.5 dia well about 3 feet away that with a 1/2 hp pump only produces around 2-3 gallons/min. ( although I never ran short of water or had any surging problems). In researching wells, I found that 25' is the max recommended depth for a shallow well pump. Anything deeper requires a packer and a jet pump to get any amount of gpm. The 25 feet is the depth to water. The depth of the well has nothing whatsoever to do with deep or shallow well pumps.

Is there a better way for me to go? Yes, put a shallow well ejector on that pump and see what it will do. If you have another well close by, the water level in it will be the same as the other well.

Can you relate the Gauze size to GPM for me? I thought I read somewhere that an 80 gauze equated to around 15 GPM. In which case my ¾ hp pump would be pretty much maxing out the screen. An 80 gauze screen is a very fine mesh. It is used to stop sand a little larger in size than powder. The flow through it and the surrounding sand is quiet slow. I would be surprised if you were to get 5 gpm through it. Since you drove this well, you will never be able to see what the water bearing formation is like or it's size. The screen could be in Pea Gravel which could use a 25 slot screen which would yield a lot of water compared to the 80 gauze in fine sand.

Because of my other pump not having any surging issues, do you think a smaller pump would work better? Something pulling around 9-10 gpm? The pump size has nothing to do with the flow. A 1/2hp pump can produce aroung 10 gpm. So your reduced flow is on account of the well and screen not the pump.

Sorry for all the questions, I really do appreciate any help I can get!
I'm sorry for the bad news, but I think you need to go back to the drawing board. The way to drill a two inch well; is to first knock the casing in the ground (no screen) then drill it out using a 1" pipe with a chisel shaped bit that water can be forced through with a good sized centrifugal pump. Once you go out the end of the pipe, you will get samples of the formation flowing up the 2" pipe. When you get into clean sand/gravel, that is where the water will come from. Not clay, or dirt. The well will also start drinking the circulated water you are drilling with, this is a good indication the formation will make water. Once you get there, you can drive an 1-1/4" screen through the end of the pipe that is consistant with the formations size, with a K-Packer on the end or with the use of a Bremer Check and the well is done.

bob...

[Rancher]

Bob, do you need lessons on how to quote also? I do like your color change.

[speedbump]

I have to do that Rancher so I won't forget the questions. With my old brain failing like it is, I have to take every advantage.

bob...

[sucker dave]

If I switch to a shallow jet pump, do I need to run a 1.25 dia pipe with a foot valve down my 2" well so I don't have to draw the water all the way up each time?

Outstanding information. thanks!!!

[speedbump]

It makes for a much better installation. No loss of prime and you don't have to worry about air leaks in the casing.

[sucker dave]

would you go with PVC or steel?

[speedbump]

If it were a submersible I might be leaning toward the galvanized. It all dependant on the water quality.

In a shallow well install, with you only needing 30 feet and a footvalve, go with the PVC. In fact we use 160 psi. PVC all the time for that and have 0 problems.

A lot of people recommend SCH 40 PVC. We don't use it at all. Just the thinwall. It bends instead of breaking, has a larger inside diameter to carry more water (less friction loss) and can be bent into a U and inserted into the bed of a pickup. Don't try that with SCH 40.

bob...

[sucker dave]

thanks!!! I appreciate the help. I'm going to try the shallow well jet. I'll let you know what happens.

[sucker dave]

I've now installed the shallow well jet pump.

Because of the low level of water in the well, I hammerd down another 5' section of pipe. I'm now down 33' to the well point and have 5' of standing water in the bottom of my well. I wasn't able to use a picture pump to pump out the dirty water so I dropped a hose down to the bottom of the well and flushed out the silty water.

I have 32' of 1 1/4" galvanized pipe with a foot valve at the end.
With a 3/4 hp convertable jet pump, I'm only getting 2 gallons a min with no pressure out of the well now.Far from what I'd like have.

Am I just too deep for the pump?

Any suggestions???

Thanks and Merry christmas!

[Rancher]

I'm now down 33' to the well point and have 5' of standing water in the bottom of my well. Am I just too deep for the pump?

I you're trying to suck water out of a well where the water level is 28" below the pump, yes you're too deep for a shallow well jet pump.

Rancher

[sammyhydro11]

Dave,
what happened with that other well? How deep is it in relation to your newly driven 2" well and what is the static water level in it? How long is your well screen and at what depth did you install that jet assembly? You have to keep that jet assembly out of the screen or the packers wont seal.

Whenever someone drives a screen into unknown material,its a safe bet to go with a 10 slot(10 thousands of an inch) screen and try to get a good 5 to 10' past the water table. sometimes these wells need to be developed depnding on the size material you drove the screen into. I advise you to use sch40 pvc w/thin wall steel or brass couplings on your dop pipe. this will make it much easier to remove the jet assembly and will keep corrosion down.

i would get some more info on that other well. if at one point it was producing a good amount of water,try to duplicate it the best you can.

OR GET AN AUGER RIG IN THERE, HAVE SOMEONE PUT IN A 4" WELL,AND FORGET ABOUT It.

SAM

[sammyhydro11]

Dave,
a little typo on my part. Make suer you have a minumum of 5' of water above that screen.

SAM