Im at a Loss as to What Is Wrong!

TVL · Aug 5, 2008

A few weeks back I posted a thread with some well concerns and got some very good responses. Armed with the information, I pulled the submersible pump and discovered the galvanized connector located just above the pump was badly corroded and was leaking. This is the connector which attaches the pump to the 1 inch poly pipe. I thought to myself, great ................. this is my problem and it should be an easy fix. Well, it certainly was "A" problem, but not the complete problem.

I replaced the entire 132 feet of 1 inch drop pipe with new pipe and new fittings and dropped the pump once again. The pump now runs for approximately 3 hours with a completely steady 36 PSI. After approx. 3 hours the pressure will begin to drop a small amount and begin fluctuating. After about 5 hours of continuous operation, the presuure gauge will indicate about 31 PSI and every 5 or 10 seconds the pressure will drop to approx. 26 PSI and then quickly return to 31 PSI.

1- Can a submersible pump that is possibly on its last leg cause this type problem? (the pump is 13 years old)
2- If so, how? I really do not want to replace it unless there is good evidence the pump is failing.

This pump and well is used for irrigation purposes only .............. so, I do not have to do anything right away. But, all responses are appreciated!

Bob NH · Aug 5, 2008

When the pump is delivering 36 psi, what is the flow in GPM? Are you using any water during that time?

A leak could cause the symptoms you are describing.

You could diagnose it by measuring the current to the pump. If the current is much lower than the normal for that motor then the problem is probably a worn pump or lack of water in the well. If the current is higher than normal then it is pumping more water than normal and there is probably a leak.

Sponsor · 2022-01-29T12:20:58-0800

TVL · Aug 6, 2008

Bob NH said:
When the pump is delivering 36 psi, what is the flow in GPM? Are you using any water during that time?
QUOTE]

This well is used primarily for our sprinkler system and pumps approximately 12 gallons per minute at 36 PSI. The well was dug in 1978 and is 145 feet deep. From past experience, the pressure gauge normally reads a STEADY 36 PSI no matter how long the system has been run and we have run it continuously for 12 hours or more on many occasions.

What we have experienced the past several days is this:

1- After sitting idle overnight, we cut the sprinklers on and check the pressure gauge about every hour.

2- The pressure gauge reads a STEADY 36 PSI until approximately the 3rd or 4th hour after which we begin to see a small decrease in pressure.

3- On or about the 3rd or 4th hour, as the pressure decrease to about 33 PSI, we will also see the pressure reading drop 2 or 3 PSI very briefly and then return to 33 PSI.

4- After about 5 or more hours of continuous operation, the pressure reading will be down to approximately 30 PSI and the gauge shows a drop in pressure of approximately 4 PSI every 5 to 8 seconds. The drop in pressure last only a split second and the gauge quickly returns to 30 PSI. This continues until the system is cut off for the day.

5- The following day, its back to item #1 above and the sequence begins again.

Yesterday, I did check the current draw with the motor running. At a steady 36 PSI the pump was pulling 9 amps. After several hours of continuous operation, the gauge was reading 30 PSI with momentary pressure drops of about 4 PSI. The current draw at this time was 9 amps with very brief current drops of approximately 1/2 amp. The current draw actually flutuates as does the pressure fluctuaions.

So, is this possibly the pump or somethinng else???

Thanks!

Valveman · Aug 6, 2008

It sounds like you are using slightly more water than the well can produce. The bobbing amp draw and pressure are the clue. If it was a pump problem, it would happen in the first few minutes. Sprinkler nozzles wear out and get bigger over time. So your sprinkler system is putting out more water than it used too. Decrease the size of the zones by one sprinkler or install smaller nozzles in all the worn out sprinklers and you should be good to go.

TVL · Aug 6, 2008

Thanks ValveMan!

I have another question for you or anyone else out there willing to respond:

Is it reasonable to expect a well to dry up after many years of use??

The reason I ask is the individual which dug our well in 1978 informed me that we had an excellent supply of water and the well was capable of producing approximately 30 gpm with absolutely no problem. That may not be the case today, if what you have stated about not having enough supply is true.

I do know lots of families around our part of the country are putting in wells for sprinkler systems. And I do realize that here in central Souh Carolina, we are probably still considered to be in a drought area. We have gotten rain this year, but not all that much ............... but last lear was really dry.

So, do wells generally dry up "naturally" OR is it a combination of the drought and everyone putting in a well? I do believe I already know the answer, but just want to hear it from an expert.

And last, if I were required to put in another well, about how much deeper should I expect to go to get a bountiful supply. I am currently at 145 feet and it is a sand well. I do realize the answer would be speculation on your part, but your experience may help provide an answer.

Thanks so much!

Valveman · Aug 6, 2008

It depends on the area. Some wells are affected by drought, some by other wells in the area, and some by both. Your well is not dry, it just can't produce as much water as it used too. It may have been able to produce 30 GPM in the past but, with neighbors drilling wells and the drought, it may now only make 20 GPM or so. You can't pump 30 GPM if your well only make 29 GPM but, if you readjust your sprinkler system for 29 or 28 GPM, it may never give another problem.

You probably have a combination of problems. Your well is not making as much as before, and the sprinkler are letting out more than before. Reduce the number of sprinklers or decrease the nozzle size and try again.

You will have to ask a local well driller about the water table in your area.

Im at a Loss as to What Is Wrong!

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