A boring thread

[Gingermick]

There is a bore in my back yard and I am having trouble getting water out of it. Standing water level is about 3m down and the bottom of well is about 4m farther. So there's 4m of water down there.
Get the new pump primed and the water pours out goodly, like a healthy person after 6 beers, then after about 30 seconds or so, it turns into an old fella with prostate problems.
I'm guessing that it's taking the 4m of water from the sleeve and the waater from the surrounding aquifer is not flowing back in near fast enough.
There is iron oxide in the water and my first look at the foot valve yeilded a big rum ball sized lump of brown crap.
I think this is blocking the screen.
So, does anyone know how I may fix this?

[JohnM]

may be worth trying blowing it - big compressor, hose down the hole, sharp bursts of air. Even if it doesn't work it's lots of fun, and messy!!

There are commercial compounds available, but I never had much success with them.

Sad to say, inmy case I had to have another hole dug.

There, aren't you pleased I was so helpful :confused:

[Ashore]

As the char lady said to the bishop
not deep enough
Or are you sucking more than the sub surface water flow provide.
Don't stop at the first water, the best is found in white sand
Perhaps Though you are saying you have a well 7 meters deep or are sucking from 3m
One of the best I saw was a bore 4" diam, plastic pipe with the bottom length
1m drilled with 1/2 " holes and the bore 2 1/2" lowered into the the 4" tube
Could be easily pulled up and cleaned
Bore is 14' and works like a charm




Useless infomation for the day


Man who run in front of car get tyred.

[journeyman Mick]

Mick what size is the outlet and how long is your discharge line? If your inlet and outlet are close to the same size (popular size is 1 1/2" in, 1 1/4" out) then the outlet can only be run full open against a fair head. The higher you are lifting with the suction side the less discharge you will be able to get.

I have a bore pick up at 26M. At this depth I need a venturi pick up, some of the outlet side water is pumped back down a second tube in the shaft to the venturi at the bottom to force the water up the inlet. My inlet is 1 1/2" and the pump will run two sprinklers out of 1/2" hoses for about 2 hours before the water level in the bore starts to drop and outlet decreases. When this happens it's neccesary to throttle back the outlet otherwise you draw air into the pump and it will cavitate (your old fella with prostrate problems). The line that feeds my tank is 1" which has about twice the capacity of two 1/2" hoses. When I fill my tank it's neccesary to throttle the outlet right back otherwise there's not enough back pressure.

So to sum up, there's two factors here:
your bore's draw down capacity (how much water it can consistently deliver) and:
the output capacity of your pump relative to how much water it can deliver from the depth it's lifting it from and the head it's pumping against.

The pump manufacturers have tables for each model pump which give all the figures of water delivered against head X and drawing from Y depth (head is not just height, it also includes friction a canvas hose will have more friction than poly pipe). There's also tables (I've got some somewhere) which give you figures for calculating head for different heights/pipe diameters/lengths/diameters. However the easiest fix is to prime your pump and throttle back the outlet almost completely before starting the pump. Run the pump and slowly open up the outlet. Experiment (you'll probably need to reprime the pump a few times) until you find a setting that will allow you to pump for a few hours or however long you want without the pump losing prime. Once you've found the setting that works close the outlet right down whist counting how many turns is required. Make a note of this setting for future reference - just in case some helpful soul decides to "help" you by opening that tap[ so you can get more water.

Mick

[Gingermick]

Thanks fella,
Mick I did try blocking off the outlet (32mm in 25mm out reduced to 3/4") Just using a valve requiring a 90° turn to completely shut off as opposed to a tap. It ran for about 2 minutes at about 80% off and as there was only a trickle I watched the pressure guage. It went from 30kpa to 0 after 2 minutes then I guess it was getting air.
I figure (hope) that its drawing dowm to the bottom (foot valve 7m deep) then sucking air as the screen around the well is clogged. I live in a very sandy area (and have cleaned the sand from the well.)
The time it runs well would be about the time it takes to fill 4m of 4 inch pipe. just guessing

The pump is 1hp and came with a tank my father bought so he gave it to me, maybe I need to put those savings into sinking another well?

[outback]

Lots of info already given to you, some good, some well meant but a little misleading in my opinion.

I'm guessing that your pump is an ordinary garden variety pressure pump.

None the less from your description your guess that you are pumping the hole dry is probably correct.

The fact that you have found iron oxide in the hole is bad, really, really bad. You can spend anything from about $500.00 to about $5.00 to try and remove it. It may help in the short term, but it won't give a full time cure. If you wish to try and have a go, what you need is basically an organic acid. For a hole your size, I'd reckon 1L of pool acid could be considered. BE CAREFUL. It's acid, and it will produce fumes. There are safer options which I would reccomend in preference.

Has the hole been in production for long?
In continuous use, or fired up after a break?

As others have said, a new hole may be the go. I was forced to do this late last year when iron oxide beat me in my old bore. The new one was sterilised immediately on completion of drilling to prevent a re-occurence.

Ask around to see if anyone else has a bore near you, and how deep it is. In my case I drilled to 112 metres to find water, worked out a little expensive.

[Auld Bassoon]

There is a bore in my back yard and I am having trouble getting water out of it. Standing water level is about 3m down and the bottom of well is about 4m farther. So there's 4m of water down there.
Get the new pump primed and the water pours out goodly, like a healthy person after 6 beers, then after about 30 seconds or so, it turns into an old fella with prostate problems.
I'm guessing that it's taking the 4m of water from the sleeve and the waater from the surrounding aquifer is not flowing back in near fast enough.
There is iron oxide in the water and my first look at the foot valve yeilded a big rum ball sized lump of brown crap.
I think this is blocking the screen.
So, does anyone know how I may fix this?

It's called a big red thingy with a fuse in it. You light the fuse thingy and drop in the hole (fishing, Dundee-style)

Cheers!

[journeyman Mick]

Mick,
if there's enough room down the bore piping drop a wooden float on a string down and mark the string. Fire up the pump and see if the water level drops. It certainly sounds like the bore simply can't supply the required volume to keep the pump going. (exceeding the bore's draw down capacity)

Mick

[Gingermick]

Has the hole been in production for long?
In continuous use, or fired up after a break?

We bought the house end of 2003 and it had been a rental for a while before that with the bore not being used. It probably sat idle for 5 or more years.
I'll check the draw down
Thanks fellas,