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Wet_Boots

Supreme Member

Posts: 5,288

Location: Metro NYC

11

Wednesday, May 6th 2015, 10:45am

the well log report helps a great deal, especially since the standalone photo of the well point doesn't immediately make it obvious that it's a 2-inch point

a 2-inch point driven 74 feet down does make sense - unfortunately not with the existing pump - to bring up water from deeper than 25 feet from a 2-inch point, you will require a Deep-well Injector Assembly in combination with a Convertible Jet Pump - this is advanced work

For small dollars, you can reconfigure the plumbing to allow you to backflush the point. It might be all you need, and it might be needed on a regular basis from here on out. Also, you can check the water table while you have the point open.

af4ex

New Member

Posts: 11

Location: Florida

12

Wednesday, May 6th 2015, 3:20pm

I'm still trying to determine if the lack of pressure is due to a clogged well or a defective pump.

To test the pump I connected it to a homemade adapter through the sediment filter, which allowed me to time how fast it could drain a bucket of water (4.5 gallons). I used a piece of 1 1/4 " pipe, which fit perfectly in the filter holder, taped to a section of garden hose.

It took 38 seconds to drain the bucket with the pump still connected to one of the sprinkler zones. That's about 7 gpm, which is a lot less than I expected.

I measured 8 gpm a month or so ago when it the system was operational (but skipping zones). But then it was also drawing the water out of the ground, which is an extra load on the pump. (It's a 1HP cast-iron Sta-Rite, which the previous owner told me was installed last year in an attempt to fix the well.)

Without having to draw from the ground I think I should be getting a lot more than 7 gpm. Right? What should the throughput be in gpm, just pumping water already at ground level?

Is this a valid test? Maybe the garden hose is restricting the flow. Should I try a larger pipe to draw the water out of the bucket?

af4ex

New Member

Posts: 11

Location: Florida

13

Wednesday, May 6th 2015, 3:36pm

@Wet_Boots
"...you will require a Deep-well Injector Assembly in combination with a Convertible Jet Pump - this is advanced work."

Are there any discussions on this forum describing how to convert an existing single-drop system like mine into deep-well injection system? The contractors I have talked with don't want to mess with the current system. They just want to cap it and drill a 200 foot well. I think that's overkill. A 70 foot well should work because the water table seems to be about 20 feet down. And it's been working as a shallow well (more or less) until last week.

Wet_Boots

Supreme Member

Posts: 5,288

Location: Metro NYC

14

Thursday, May 7th 2015, 6:17am

You should break down the existing system into numbers that can be used to match to a water supply. The common centrifugal pump is really designed for lower pressures and high flows. That 1-HP Sta-Rite can pump over 30 gpm from a shallow unrestricted groundwater source.

If your pump is drawing from a clogged point, or too deep a water table, it might be possible for cavitation to be happening, and that can do physical damage to the pump, and all by itself reducing pump output.

Convertible jet pumps are advanced work. They are, however, the very thing for feeding a sprinkler system from a well point with a low water table. I capitalized some of the relevant words, so you can do a search. (one more term - the type of injector that fits in a well point is known as a Packer)

This post has been edited 2 times, last edit by "Wet_Boots" (May 7th 2015, 6:33am)


af4ex

New Member

Posts: 11

Location: Florida

15

Thursday, May 7th 2015, 10:25am

I beefed up my home-brewed "pump tester" with all 1 1/4" pipe, which now offers little or no restriction to the flow of water from the bucket. (Be careful with the extended pipe, it can possibly break the filter holder receptacle)

If 30gpm is the 'norm' for this pump, then it should empty the bucket in less than 10 seconds. But when I switched on the power, the motor started up, but nothing happened. No water was drawn from the bucket. Yesterday I was getting 7gpm.

So, with some confidence, I finally know the direct cause of my low pressure. A burnt-out motor/pump. Still can't rule out a clogged well, because that might have been the cause of the pump failure.

At least I have a much better understanding of the problem, and hopefully others may benefit from my experience. So I suggest that everyone with this same problem first contact the city/county records clerk and locate your 'well completion' report, which will tell you how deep the well is and the water table when it was built. Also I think my home-made pump tester is a very simple way to tell if your pump is operating up to its specification.

I did some further checking and learned that most of the shallow wells in this area are 50-75 feet deep, because the 'ground' here in Florida is mostly sand down to that depth. They drill until they hit 'bedrock', which may be just calcified shells, sediment etc. But this helps to insure the screen will be encased in rock, not sand which quickly clogs the wells. Of course the water table has been less than 25 feet to permit the water to be sucked out with a simple centrifugal pump.

Also learned that the 'convertible jet pump/injectors' (which allow pumping down from 90 feet) have a big downside: greatly reduced flow. Half of the water flow is 'wasted' to operate the submerged jet.

And thanks to Wet_Boots for his prompt and useful comments.

Wet_Boots

Supreme Member

Posts: 5,288

Location: Metro NYC

16

Friday, May 8th 2015, 6:48am

While you are making bucket tests, you must be certain that the suction side connections are completely air tight. You would have an easier time if you had a couple of unions plumbed into the intake.

af4ex

New Member

Posts: 11

Location: Florida

17

Friday, May 8th 2015, 8:54am

I'm not a professional plumber, so was looking for a "simple as possible" solution (but not too simple). The 1 1/4" pipe into the filter socket is a reasonably tight fit, so does the test satisfactorily for me. It merely answers the question: "Is this pump working OK, or not?"

Plumbing onto the outer chamber won't work because it contains a second outlet to the well. The inner socket (see photo above) permits the test pipe to have an exclusive connection between pump and bucket. I think that is "simple as possible" and effective too.

Just be careful not to wiggle the pipes or you might break the inner socket. My filter holder already had some exterior cracks from old age, so I had to replace it (see photos above), which I was able to do myself. The replacement filter holder (minus filter) cost $22, not too bad.

Wet_Boots

Supreme Member

Posts: 5,288

Location: Metro NYC

18

Friday, May 8th 2015, 10:06am

You should do more investigation. If your existing pump is bad, what made it go bad, and can a replacement also go bad? What is the water level today?

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