Gauteng Smallholder December 2015-January 2016 | Page 42
WATER CRISIS
fine delivery you may wish to
From page 39
it take into account fluids that
end up in the drain as a result
of agricultural pursuits on a
smallholding such as dairy,
abattoir or stable-yard washdown water.
Not surprisingly, the resultant
liquid containing these
substances, if allowed to
stand for a short time soon
starts to smell as the solids
and organic components
putrefy, giving off the familiar
sulphurous odour of a
blocked drain.
And also, not surprisingly, if
the water is not filtered the
solids contained in this stew
will soon clog up any form of
use, including sprinklers, drip
irrigators and the like.
Plus, the combination of soap
residue, human hair and the
fats, oils and greases,
combine in the cool water to
form a white, semi-hard solid
which will build up on the
sides of storage tanks and
pipework in much the same
way that cholesterol clogs
your arteries.
Just from what it contains, it is
not difficult to see that using
this liquid as-is on one's
garden will soon result in
smelly patches, an increase in
flies and other insects and,
soon enough, illness among
workers, children and animals
using the garden.
Not to mention that the
“fogs” will eventually clog the
soil, coating soil particles and
making it impossible for the
soil to absorb moisture and
release nutrients.
So before using grey water on
the garden it is necessary, at
the bare minimum, to pass it
Examples of
simple grease
traps
through a couple of rudimentary filters to take out the
worst of the contaminants.
To remove the solid food
particles, hair and much of
the fats, oils and greases, at
the very least the fluid should
flow through a conventional
grease trap, which should be
regularly emptied (you'll be
surprised how quickly the
grease trap fills with gunk).
You can buy a simple grease
trap from any good plumber's
merchant and installing one is
a simple case of digging a
hole and plumbing it into
your drain line.
Next, a combination of a
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gravel-and-sand filter, with an
anaerobic digestion chamber
will, hopefully, rid the water
of remaining organic matter,
with the anaerobic digestion
taking care of much of the
bacterial load as well.
The dimensions of such a
filter will be dictated by to the
daily volume of water it is to
process but, basically it
should comprise a tank at the
bottom with an outlet high
enough up so that the tank
never empties fully. The tank
should be partially filled with
a honeycomb of bricks (even
better if the bricks are of the
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