Gray water in the garden

I've used gray water for some years now, last summer's rather bountiful
maize crop being entirely irrigated thus. I only bother with the effluent
from the automatic clothes washing machine. At another location I was using
the shower water but since the bathroom was on the ground floor in a slab
construction house is was pretty impracticle and I gave up.

What I do is simple I run the outlet of the machine into a large plastic
garbage can, it's important that the very end of the outlet be at roughly
the height of
the highest water level in the washing machine, else evertime the machine
takes
a rest to soak the clothes, the water will siphon out. In the garbage can
I've
put an automatic level-sensing electric pump. From there I run the hose to
wherever
I want to irrigate.

I'm surprized by the
nearly unanimous agreement that the soap doesn't bother the plants. I guess
the stuff that one can use on one's skin can't be so caustic as to harm the
roots.
But on the other hand, so to speak, our powdered
commerical laundry detergents have lots of sodium carbonate which will kill
just about anything except bermuda grass (Cynodon). Also if somebody decides
to use some hypochlorite bleach, that will also leave a nice big patch of
dying plants,
not too surprizingly.

I've found that that for washing, for example, bath towels,
you really need no soap at all. Sometimes I add say 200 ml of household
ammonia in the load
in lieu of detergent
and then put an equal volumn of Epsom salts (Magnesium sulfate) in the
garbage
can to neutralize it, especially if the effluent is going over to some
acid-loving
plants such as blueberries (Vaccinium) Else I sometimes use a small amount
of
liquid laundry detergent and again some Epsom salts into the garbage can
collector.
The most expensive solution are the 'bio-compatible' laundry detergents
which are
based on Potassium salts rather than Sodium salts. My wife hates the stuff
because
it doesn't clean very well. The brand 'Oasis' used to be available in both
phosphate
free and phosphated forms, but currently I can only find the phosphate-free
type,
which is very unfortunate. Also for laundry which is merely dusty or muddy
rather
than oily, a couple of cups of vinegar in lieu of any other cleaner works
nicely
in warm water and leaves them smelling pretty good. For rust and other metal
oxides
stains, oxalic acid, while quite toxic to mammals, is harmless to plants.

I guess all this indicates a not-so-simple solution...

Another simple gray water trick is to simply hand wash big nasty items such
as woks,
and those disgusting trays in the bottom of your refrigerator outdoors in
the garden
with a reasonably mild (hand) dishwashing liquid.

Now mind you, all this is highly illegal in the local jurisdictions in which
I've lived so I'm only giving this information hypothetically.  ;)
We really live in a cacocracy here....

Karl Hoover
(somewhere in a dry summer region of North America)



-----Original Message-----
From: owner-medit-plants@ucdavis.edu
[o*@ucdavis.edu]On Behalf Of Shelley Harvey
Sent: Monday, February 26, 2001 4:54 PM
To: medit-plants@ucdavis.edu
Subject: using "grey" water in the garden



I don't know whether this is appropriate for the medit-plant list, but I
would really appreciate comments/advice from people who use or have used
household "grey" water (unfiltered) in the garden.  This water would only
be used on the general garden, definitely not on the vegetable garden.

I live in the bush and the only water I have for the general garden is from
one of the farm dams.  The water I am considering collecting and using is
from the household bathrooms (showers and basins) and the washing machine
because currently it goes to waste, and it would be relatively simple to
collect in a tank and gravity feed to various parts of the garden.  I
realise it would be necessary to use the most environmentally friendly soap
and washing powder I can find.  In previous droughts I have collected this
water and carted it by bucket, but it is very time consuming.  My concerns
relate to whether plants (or which plants?) could tolerate this type of
water on a regular basis?

Any experience people have had would be most welcome.

Shelley


Shelley Harvey
New England Tablelands
Northern New South Wales
Australia
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