Low yield water well

I have a well on my site that has been performing well for 10 years.

During this year, the pressure dropped significantly. Its now down to approx. 1 gpm.

The local water company came out to take a look. The guy told me the issue was with my pressure tank and replaced it. That didn't solve the problem.

He then told me it was the well pump, and set about replacing that. That didn't solve the problem either.

His new theory is that the yield in the well has dropped, possibly due to fissures in the rock getting filled up with sediment. He is now proposing to get a guy in to drop dynamite into the well to open up the fissures.

This all sounds fine, but to my logic, if there was less water getting into the well from the aquifer, I should experience occasions where the water in the well drops to levels where the pump can no longer extract water eg during peak usage times.

Also, if this were the issue, I would expect that after times when we have been away from the house for a number of days, that the well would refill, and pressure would be restored.

Neither is true. The pressure from the well is a constant 1 gpm, regardless of over-usage or lack of usage.

Does anyone have any other suggestions re. why the pressure would have dropped? I'm not confident that the issue is the supply of water to the well, and don't really want to have someone dynamite it unless I am 100% sure that is the problem.

Also, wouldn't some sort of intermediate storage tank solution be a better option? My cistern refills no problem. We always have sufficient pressurised water in our bathroom sinks, showers, appliances etc. The only issue is the direct feed from the well to the kitchen cold tap.

Hi, I need to clarify some details to help you move forward.

*I can tell you that he should have known if it was the pressure tank was bad before replacing it. By measuring the air pressure on the bladder, and seeing that no water came out of the air valve.
*You are correct that there doesn't sound to be anything wrong with the well itself or you would have 'ran it dry' and the water would have stopped completely for a period of time while it refilled (and depending on the kind of pump it would have needed manual intervention to prime it and get rid of the airlock)

Questions:
1) Is this pump underground or above the ground in a little shed / garage?
2) Is there a pressure guage near the pressure vessel and if so what is that reading?
3) If that pressure guage remains quite high with the taps on, you may have a restriction on the pipe from the pressure vessel (tank) to your house
4) When you say "pressure from the well is a constant 1 gpm", do you mean the flow from your kitchen tap is 4.5 L/min? Is that so bad?
5) If you have high pressure when you turn on the tap but after 20 seconds or so it drops and the pressure guage on the pressure tank remains like that you may have an issue with the footvalve (if your pump is above ground) down the well... it may have dirt in it.

Come back with more details, it should be relatively easy to help you isolate the problem.

TTI said:

1) Is this pump underground or above the ground in a little shed / garage?

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Pump is submerged in bore hole approx 170 feet

TTI said:

2) Is there a pressure guage near the pressure vessel and if so what is that reading?

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Yes, reads between 32-35psi

TTI said:

3) If that pressure guage remains quite high with the taps on, you may have a restriction on the pipe from the pressure vessel (tank) to your house

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I have an outside tap on the shed where the pressure vessel is, which is connected to the system. When I run at (at about 1 gpm when on full) the pressure remain at 35psi for 1-2 mins. The pump then kicks in, and the pressure goes up to 50psi, and then stops.

TTI said:

4) When you say "pressure from the well is a constant 1 gpm", do you mean the flow from your kitchen tap is 4.5 L/min? Is that so bad?

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It takes 18 secs to fill a 1 litre jug. I don't know. Is that bad? It used to be better.

TTI said:

5) If you have high pressure when you turn on the tap but after 20 seconds or so it drops and the pressure guage on the pressure tank remains like that you may have an issue with the footvalve (if your pump is above ground) down the well... it may have dirt in it.

Come back with more details, it should be relatively easy to help you isolate the problem.

Click to expand...

Pressure doesn't drop when taps run. The pump just kicks in.

Also, I measured the air pressure in the vessel, and its approx. 30psi.

Doing a bit of research, it seems the normal that the cut off for the pump should 60psi. If I adjust my cut off, and increase the pressure in my vessel, would that give me a bit more pressure?

Thx

Couple of things:

1) Sounds like pump and pressure vessel are fine, and also the pipe from the pump to the pressure vessel as the pressure in the tank is maintained with the taps on.
2) Checked with the plumber in the family to ascertain the nominal pressure ranges. 50 psi for the upper is fine and often it is set to maintain between 20-40psi, and "should take the jug out of your hands at 50"... I can think of the experience at their outside tap. You could raise it to 40-60psi, the small screw is to adjust the "Switch on", the larger screw is to adjust the "Switch off". Clockwise (tighten the screws), but only 1/2 a turn at a time I was advised.
3) At the outside tap you mention again about the 1 gpm. i.e. 4.5 L/minute,
and then you mention 18 seconds to fill 1 Litre jug, which is 3.3 L/minute? At the outside tap is should be maybe twice that or more.

Essentially, if your outside tap is not performing as you would expect and it is so close to the pressure tank at the 30-50 psi you observed, then there is a blockage between the pressure gauge and your outside tap. Check the outlet valve on your pressure tank, is it fully open? Is it internally blocked? Turn off the pump and let the pressure drop down... open the valve with a spanner and have a look, get a piece of pipe, etc. or garden hose and put it out the door and see what the flow is then.

TTI said:

Couple of things:

1) Sounds like pump and pressure vessel are fine, and also the pipe from the pump to the pressure vessel as the pressure in the tank is maintained with the taps on.
2) Checked with the plumber in the family to ascertain the nominal pressure ranges. 50 psi for the upper is fine and often it is set to maintain between 20-40psi, and "should take the jug out of your hands at 50"... I can think of the experience at their outside tap. You could raise it to 40-60psi, the small screw is to adjust the "Switch on", the larger screw is to adjust the "Switch off". Clockwise (tighten the screws), but only 1/2 a turn at a time I was advised.
3) At the outside tap you mention again about the 1 gpm. i.e. 4.5 L/minute,
and then you mention 18 seconds to fill 1 Litre jug, which is 3.3 L/minute? At the outside tap is should be maybe twice that or more.

Essentially, if your outside tap is not performing as you would expect and it is so close to the pressure tank at the 30-50 psi you observed, then there is a blockage between the pressure gauge and your outside tap. Check the outlet valve on your pressure tank, is it fully open? Is it internally blocked? Turn off the pump and let the pressure drop down... open the valve with a spanner and have a look, get a piece of pipe, etc. or garden hose and put it out the door and see what the flow is then.

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Thanks again.

There is a hygiene system between the pressure vessel and the outside tap. It removes minerals, smell and has UV lamp pass through.

The guy from the water company checked all this stuff and said it was fine. I'm beginning to have doubts.

If the valve is showing 50 psi, I think you're right that the tap a couple of feet down the pipe should be gushing.

Going to disconnect a few things and see what I can find out.

Re. the 1 gpm, I think I was converting to US gallons rather than Imperial (or vice versa). Anyway, its about 3 litres per minute at the outside tap and inside.

Yes, it sounds like your filter system is causing a large pressure drop due to some restriction.... There may be a coarse inlet filter that needs cleaning, etc.

goosebump said:

Thanks again.

There is a hygiene system between the pressure vessel and the outside tap. It removes minerals, smell and has UV lamp pass through.

The guy from the water company checked all this stuff and said it was fine.

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what is the "hygiene system"? When you say "water company" what do you mean? In rural Ireland you have plumbers who know a little bit about water treatment and some water treatment specialists and a very few who are good at both. What company do local farmers in your area use?

ajapale said:

what is the "hygiene system"? When you say "water company" what do you mean? In rural Ireland you have plumbers who know a little bit about water treatment and some water treatment specialists and a very few who are good at both. What company do local farmers in your area use?

Click to expand...

Its a system that removes minerals, polishes the water and passes the water over a UV light to kill bacteria.

Still don't understand, what "minerals"? What does "polishing" mean? I'm surprised that a reputable "water company" would use such vague terms. have you sought a second opinion from a reputable water treatment company?

You should have your well water tested at least once a year for bacteria, water chemistry (hardness ect) and metals (iron, manganese ect). It is a good idea to test the raw untreated water and the treated water at the tap to check how effective the treatment is.

Has your pump guy done a yield test on well?