Congratulations to Greg in Australia on what he calls the, "Oz Well." He
began with a more or less conventional auger. It worked well
through clay but kept coming up empty once he got into sand.
Greg then fabricated an ingenious and unique auger with a built in
valve. The valve allowed the auger to capture sand as it was
twisted down into the earth. Greg periodically emptied sand from
the auger, permitting him to continue augering down. He explained
that prior to fabricating rubber valves for the auger, the sand simply
fell back down in the hole.
He augered a hole large enough to install a well screen with a
submersible pump. Very impressive, Greg!
Conventional Auger Greg used in
Next, Greg made this auger with a valve so the sand could not fall out.
Bottom view of Greg's Auger showing rubber valve
Top view of Greg's Auger showing rubber valve
Greg provided the following information regarding his drilling project:
Hi Mike, Thanks for a lot of useful info on your site, I have attached
a few pics to show my bore. Dug with a home made 115mm auger using
1.2m lengths of 20mm gal pipe and sockets, then sand pump with rubber
valve when it got to the sand, I only get 2L/min or more for shorter
periods but it is much more than I can use. (@3000l/Day) 4"
submersible pump and a bore cap made from a 100mm gal steel fence post
cap works just fine.
The thing I call a sand pump is very simple
and I am sure it has been made before is to remove the wet sand.
I used a hand made auger to dig the well in the firm ground but once I
hit sandy clay the auger kept coming up empty (and clean), all the sand
was just falling out, I could keep digging but eventually it cot too
hard with all the sand on the auger.
I first came up with the
brainwave to use a 90mm pvc storm water pipe for the sand pump.
Abour 500mm long with a threaded cap on each end, the bottom end had 6
20mm holes in the cap and a 2mm thick rubber disk on the inside to close
the holes on the upstroke, a small bolt in the centre kept it in place.
In the top cap I installed a 3/4" nipple to attach the end of my
auger shaft once the auger was unscrewed, this kind of worked and filled
with sand on the down stroke but it was too weak to last long and so I
had to make a stronger version.
I made the new pump from 100mm
dia steel pipe, on the bottom I had to fit a centre to hold the rubber
disk so I used a piece of 12mm dia steel bar on which I welded 4 blades,
I them spun the assembly in a lathe so it would fit in the end of the
pipe, machined a point on the bar and ground the blades so they would
cut if required.
I tapped a thread in the top of the bar to hold
the rubber disk, (Countersunk washer & screw) the disk had 4 cuts in it
but I think it may work better without the cuts as it lost a lot of its
rigidity and sometimes leaked.
I would basically cut about 300mm
with the normal auger than remove it and fit the pump which I could
lower into the hole and as it neared the bottom I would force it down
and it would fill with slush.
Gently lift it out again and it
would be full of sand & water.
Slow process but it worked well
and cleaned the bore to the bottom.
It was especially useful
when I decided to enlarge the diameter of the hole from 114mm to 145mm,
I welded extra blades on the auger and cut my way down the hole.
I did this as I decided to follow the standard bore installation
guidelines (including disinfection) and use Schedule 9 pipe which of
course has a larger outside diameter
As you would expect it
filled the hole with slush and the pump enabled me to remove it all, it
took about 6 hours to cut the hole bigger and clean it out (9.3m).
I didn't want to go any deeper as I hit clay again and thought it was a
good enough supply, I didn't need much water.
The whole thing
was really only an experiment anyway.
I have fitted a 3/4 hp
submersible, it was the smallest I could get for a reasonable price,
it pumped the bore out far too quickly but if I closed the gate valve to
restrict the flow the pressure increased to 100psi and obviously loaded
the pump (And power usage) which I was not happy about.
I did was a little experimentation, I put a "T" in the outlet at the top
so some of the water pumped out went back into the bore thus reducing
the overall extraction rate.
I used a plastic cap on the end of
the pipe going back down the bore and drilled a bleed in it, I increased
the bleed hole diameter until I had a compromise between pressure and
Once I got the right bleed size I installed
it just above the pump pointing upwards, its just a "T" in the outlet
line at the pump with a 90deg pointing upwards and the bleed cap.
It prevents me pumping the bore dry as well as giving a audible warning
(If I listen at the top of the bore) of when the level is low, also
instead of running dry I get bubbles in the water flow as the pump takes
in air but does not run completely dry.
This also means the pump
runs without any real load so lower power use etc.
actually do is run the pump at about 12l/m for 5 minutes every 15
minutes during the day as I have solar power on the house, this means I
get the most water with the least pump run time.
This is enough
to water the garden and general yard watering.
I am installing a
5000l tank and pump next week so I can fill it and keep it full so I can
get all the water I want when I want it.
Hope this all makes
An interesting and satisfying experiment. The hard
work digging was good for me.
The whole thing started when we
had a really heavy rain storm (200mm in @ 2 hrs) and I decided to put in
additional drainage, when I went to install a storm water pit the hole
kept filling with water because of the high groundwater level so I
thought I would dig a bore to make use of it.
The level has
settled at about 2 m when it is dry.
I asked him about his pump.
The pictures attached are of
the pump, I suppose it is not really a typical pump, its just what I
It is attached to the long length of pipe I use to
drill the hole with the auger once the auger is removed.
of the pipe has a "T" handle like a normal post hole auger and you push
it down into the mud at the bottom of the bore, the slush is forced up
past the rubber valve and stays there as you lift it out to empty it.
It can bring up about 250mm of slush each time.
I was using
the "Pump' twice to each 500mm of hole digging with the auger.
Painful swapping from auger to pump each time but it works fine.
The timber across the hole with the pieces of angle allowed me to bring
the pipe about 3m at a time so I could remove it in pieces without it
dropping down the hole, the joiner (3/4" union) where I unscrewed the
tube sat behind the angles so the tube could not fall into the hole.
Once you get longer than about 6m the pipe and handle is a bit long
to lift out safely so I would take it apart each time.
to explain all this in writing.
Here are pictures of his installation as well as
a sample picture of a pump like his.
Many thanks to Greg for sharing his story with