New more powerful borehole pump severe quality degredation

[yinmeout]

I read with interest other Borehole threads on here and so I am wondering if any of you might be able to shed any light or advice on my problem.

On sand where we are, I had a borehole pump producing crystal clear water for the last 2 years (since I took the place) over at 24lmp. I recently installed a sand trap which needed cleaning out every 18m³.

I have recently had to replace the 15yr old pump with another pump. The new Pedrollo unit (they are exceptionally sand tolerant) produces 60lmp, its a combination of slightly more power (pulls 6A and the old one pulled 5A single phase), newer tech and a larger bore delivery pipe. The side effect of this is that the water is extremely bright yellow now and my sand filter gets blocked after about 2m³. You read that right.

The old guy who originally drilled it is 86 now and frankly I was amazed that we manged to pull out the old pump together and replace it. If I am going as well as he is at that age I shall be delighted. However, he left with a cheery wave after we dropped it into the hole and here I am.

What might I do to get the hole running clearer is the question?

I assume I am pulling silt and sediment from new regions underground and this is the cause.
About the only thing I can think of is to run the pump continuously for some time, to drag all the loose material out of the hole and eject it?

 

[Roger Perry]

I read with interest other Borehole threads on here and so I am wondering if any of you might be able to shed any light or advice on my problem.

On sand where we are, I had a borehole pump producing crystal clear water for the last 2 years (since I took the place) over at 24lmp. I recently installed a sand trap which needed cleaning out every 18m³.

I have recently had to replace the 15yr old pump with another pump. The new Pedrollo unit (they are exceptionally sand tolerant) produces 60lmp, its a combination of slightly more power (pulls 6A and the old one pulled 5A single phase), newer tech and a larger bore delivery pipe. The side effect of this is that the water is extremely bright yellow now and my sand filter gets blocked after about 2m³. You read that right.

The old guy who originally drilled it is 86 now and frankly I was amazed that we manged to pull out the old pump together and replace it. If I am going as well as he is at that age I shall be delighted. However, he left with a cheery wave after we dropped it into the hole and here I am.

What might I do to get the hole running clearer is the question?

I assume I am pulling silt and sediment from new regions underground and this is the cause.
About the only thing I can think of is to run the pump continuously for some time, to drag all the loose material out of the hole and eject it?

Here in Colorado when we drill a new well it is test pumped hard for several days on and off to clear all the sediment.'

 

[davidroberts30]

I read with interest other Borehole threads on here and so I am wondering if any of you might be able to shed any light or advice on my problem.

On sand where we are, I had a borehole pump producing crystal clear water for the last 2 years (since I took the place) over at 24lmp. I recently installed a sand trap which needed cleaning out every 18m³.

I have recently had to replace the 15yr old pump with another pump. The new Pedrollo unit (they are exceptionally sand tolerant) produces 60lmp, its a combination of slightly more power (pulls 6A and the old one pulled 5A single phase), newer tech and a larger bore delivery pipe. The side effect of this is that the water is extremely bright yellow now and my sand filter gets blocked after about 2m³. You read that right.

The old guy who originally drilled it is 86 now and frankly I was amazed that we manged to pull out the old pump together and replace it. If I am going as well as he is at that age I shall be delighted. However, he left with a cheery wave after we dropped it into the hole and here I am.

What might I do to get the hole running clearer is the question?

I assume I am pulling silt and sediment from new regions underground and this is the cause.
About the only thing I can think of is to run the pump continuously for some time, to drag all the loose material out of the hole and eject it?

Lift the pump up a couple of ft?

 

[yinmeout]

Lift the pump up a couple of ft?

I wondered about that - the pump is currently above the well screen which is from 32-35m (bottom 3m) at 30m in 10m of water. If I raise it I will have to cut various wires and pipes - and then replace the lot at around £200 if I want to lower it a couple of feet again. So this would have to be a last resort.

 

[davidroberts30]

I wondered about that - the pump is currently above the well screen which is from 32-35m (bottom 3m) at 30m in 10m of water. If I raise it I will have to cut various wires and pipes - and then replace the lot at around £200 if I want to lower it a couple of feet again. So this would have to be a last resort.

Have to pump flat out to waste for a few days

 

[yinmeout]

Here in Colorado when we drill a new well it is test pumped hard for several days on and off to clear all the sediment.'

That makes sense to me.
Can you say what the on off frequency is that is used?
12h on 1hr off / something else?

+I phoned the guy (borehole guy today) and the summary of his output is that he thinks it will "always be like that" and assumes that the problem is caused by the large intake of water when the pump starts. With the benefit of being here though, it looks very much to me like there is a constant draw of material (sediment and some sand) all the time into the tank.

So I feel a good long pump would pull allot of that out of the ground.

 

[yinmeout]

I just went up and took a sample in a glass and its almost clear - so I think I need to empty the tank and wipe it out (takes an hour). Then fill again as my view is clouded, no pun intended. I realise looing through 2.5m to the bottom (10m³) looks very different than a glass.

I just found out that the way my mate was told to do it was run the pump 15 mins in every hour.
So if it's crap again once I fill it up - i'll do that for a week and see where I am.

Thanks for all the replies.

 

[Roger Perry]

That makes sense to me.
Can you say what the on off frequency is that is used?
12h on 1hr off / something else?

+I phoned the guy (borehole guy today) and the summary of his output is that he thinks it will "always be like that" and assumes that the problem is caused by the large intake of water when the pump starts. With the benefit of being here though, it looks very much to me like there is a constant draw of material (sediment and some sand) all the time into the tank.

So I feel a good long pump would pull allot of that out of the ground.

When drilling an irrigation well of lets say 200ft as an example, usually this will be around 18 inch diameter. The first say 100 ft will be solid casing then perforated casing to the bottom of the hole.......lets say the static water level is at 120ft (from surface) you want to set you pump as far off the bottom as possible but below the draw down level.
Its' not good to be pumping from the bottom.
When you test pump it needs to be done with a pump of greater capacity than the one you will finally install...........the test pump will stress out all the debris.
We have free flowing wells around here 1200-1800ft deep installed 80 plus yrs ago.....still going strong.

 

[davidroberts30]

That makes sense to me.
Can you say what the on off frequency is that is used?
12h on 1hr off / something else?

+I phoned the guy (borehole guy today) and the summary of his output is that he thinks it will "always be like that" and assumes that the problem is caused by the large intake of water when the pump starts. With the benefit of being here though, it looks very much to me like there is a constant draw of material (sediment and some sand) all the time into the tank.

So I feel a good long pump would pull allot of that out of the ground.

When ours was installed a 100lpm pump was running 24 hour a day for weeks to waste
Then a 50lpm pump was installed for working

 

[yinmeout]

I just went up and took a sample in a glass and its almost clear - so I think I need to empty the tank and wipe it out (takes an hour). Then fill again as my view is clouded, no pun intended. I realise looing through 2.5m to the bottom (10m³) looks very different than a glass.

I just found out that the way my mate was told to do it was run the pump 15 mins in every hour.
So if it's crap again once I fill it up - i'll do that for a week and see where I am.

Thanks for all the replies.

I sump pumped out and cleaned out the tank just now, (getting that operation down to a fine art). The tank is now half full again and it all looks as clear as the pint glass sample did. I can't see the bottom but it is absolutely NOT yellow at all. Just a touch cloudy, probably 3ft visibility. Considering it's only had around 25m³ through it since it was last cleaned it out there was much more fine sand in the bottom than I could have imagined. A bit surprising considering every drop has passed through 130 micron screen.

I guess the entire problem was not pumping to waste enough (at all really) when the new pump went in. Wasn't told to, didn't know. Can't know what you don't know.

Therefore, it looks like the debris is coming out, and it will eventually clear itself as the old one did before. I'll check the sand trap in an hour once the tank has filled again in preparation for the morning irrigation run of 14m³ but I based on what I can see, I think we are definitely heading in the right direction and my sand filter run time is going to get to an acceptable level which was my main concern.

Getting up in the night because the borehole pump is unable to discharge isn't my idea of fun or a sensible way of making Pedrollo wealthy. But hey it's still allot better than buying the water from the utility company !