Shallow well,low GPM

[renrag]

I'm at a loss for ideas. I have a shallow 2" sand point well adjacent to a lake in Northern Wisconsin. The well point is down 22.5 feet and water in pipe is at 7.75 feet from the surface. I have a check valve between the pump and the 2" well casing. I have a 1 hp shallow well pump. On discharge side I have 3.5 gallon bladder tank right next to pump. Inside the house I have a filter and a 10 gallon bladder tank. Pump is set to kick on at 30 and off at 52. I can only manage 1/2 gallon per minute. With the bladder tanks we can get by but I'd like to increase the gpm to 2 or 3 gpm, life would be a lot easier.
Today I took off the cap at the T between the well and the pump. When I did that the water was near the top and it slowly sunk to 7.75 foot level.
In previous years I had other sand point wells in the area, 15 feet deep and had plenty of water.
Is it possible my point is plugged? Is it possible I am too deep, went through water vein?
I'm too tight to hire a well driller so....
Any advice would be appreciated.

tomahawkpaul

 

[Valveman]

With a new point, either the point is not in the water bearing formation, the point is clogged, or screen is too small. Water falling back slowly is a key. A well that won't take water, won't make water.

 

[Sponsor]

 

[renrag]

With a new point, either the point is not in the water bearing formation, the point is clogged, or screen is too small. Water falling back slowly is a key. A well that won't take water, won't make water.

With a new point, either the point is not in the water bearing formation, the point is clogged, or screen is too small. Water falling back slowly is a key. A well that won't take water, won't make water.

 

[renrag]

Thanks valveman. Does that mean if it takes 3 or 4 minutes for the water to drain down to static level, most likely my screen is clogged? Pretty sure I'm in sand bearing water area, 20 feet puts me down to surrounding lake level.

 

[Valveman]

Something is clogged. Either the screen is clogged, too small, or it is not in a good water bearing formation.

 

[shane21]

I tend to agree with you and valveman that the problem is related to the production capabilities of the screen or formation.

A somewhat unorthodox method you could use to verify this is to set up the jet pump on like a 1/2" suction line (with a small diameter foot/check valve) down inside the 2" drive point casing and get it ready to pump. Once you get the jet pump primed you can use a throttling valve on the pressure side of the pump and start slowly opening the valve and measuring flow rate until you hear the small suction line in the 2" casing break suction. This would take maybe 2 hours of your time and cost you $30-$50 in additional material/parts or so to have a definitive answer.

If you establish the production of the well is the problem you can then try using a pump and a tank of clean sanitary/potable water to push water into the 2" casing under pressure and attempt to crudely "develop" the well by flushing water out into the formation through the drive point screen. Reverse flowing water through a screen in any well can sometimes increase production of the well.

If all else fails you can always install a larger reservoir tank in the house and use the 1/2 GPM well to slowly fill the reservoir tank. 1/2 GPM isn't a good producing well but it is equivalent 720 gallons per day, if pumped for 24 hours, and a reservoir system to hold even 25% of that 720 gallons would probably be a night and day difference for you.

 

[Reach4]

Try this search in a search engine:
"well point" unclog air compressor

I have no relevant experience.

 

[shane21]

Yes an air compressor would also work, just need to make sure you have one capable of producing enough cubic feet per minute (CFM) of air to do the job.

 

[Valveman]

Once you get the jet pump primed you can use a throttling valve on the pressure side of the pump and start slowly opening the valve and measuring flow rate until you hear the small suction line in the 2" casing break suction.

That is a good idea. And see "throttling valves" are used all the time and they do not hurt a pump.

 

[shane21]

Throttling valves never really hurt a pump, it's really only the motor cooling that you may have to be concerned about. In this case we are dealing with an air cooled motor so the cooling is taken care of by the fan arrangement on the motor itself and it is not dependent on water flow for cooling like a submersible motor.

 

[Valveman]

Throttling valves never really hurt a pump, it's really only the motor cooling that you may have to be concerned about. In this case we are dealing with an air cooled motor so the cooling is taken care of by the fan arrangement on the motor itself and it is not dependent on water flow for cooling like a submersible motor.

Not true anymore. Throttling won't hurt the pump as long as there is 1 GPM flow, but some pumps that have floating stage type impellers will drag and need more cooling than the motor.

 

[shane21]

Hmm, I will need to get out my technical specs on the Goulds JS+ line to check into that. I have never seen that referenced anywhere that I can remember but it's very possible I have overlooked it. Thanks for the heads up!

 

[Valveman]

Has nothing to do with the Goulds JS. The bad floating stage type pumps are submersibles made by Franklin and Pentair. Pentair has always been OK, but Franklin pumps have been cheapened up until they can't survive with low flow rates.

 

[shane21]

Okay so there isn't a 1 GPM minimum flow rate for the Goulds jet pump we are discussing in this thread. Sorry, your post was a bit confusing as I thought you were implying the Goulds J and JS+ series pumps had a 1 GPM minimum flow rate which would have been news to me since I had never seen such a requirement in any Goulds literature over the 25+ years we have been using them.

 

[Valveman]

Yeah strange they don't mention a minimum flow on jet pumps when we all know they will melt down if starved for water. My tests from decades ago showed 2/10s of a GPM is a safe flow with a jet pump. The water starts heating a little at 1/10th of a GPM. We had to test this on all kinds and all sizes of pumps to know how to set the minimum flow in a Cycle Stop Valve.

 

[Boycedrilling]

First pump dealer I worked for had about a dozen bulged or blown apart pvc discharge pipes mounted on the wall. John would show them to his customers as an example of what happens to a centrifugal pump discharge is the pump was left running with no flow.

 

[shane21]

Yes I have seen quite a few of those, also have seen 4' runs of PVC on the suction side of the pumps that looked like pex tubing they were sagging so badly from the heat. The best PVC warp I ever saw was in a 110' well with the pump hanging at 80'. About a 10" section of the 2" Certa-Lok just above the stainless Certa-Lok nipple was ballooned to almost 4" OD.