From page 36
SEWERAGE
and detergents in the water
are made up largely of
phosphates and nitrates which
constitute a major part of
chemical fertilizers.
Or, thirdly, one can use it to
feed a marshy wetland which
will attract insects and bird life
to one's garden.
One can't, of course, use it as
drinking water for livestock,
and one can't (legally, at least)
discharge it in any way that it
will run into an existing
watercourse or river.
To make use of grey water
requires a bit of ingenious replumbing of the house. First,
one will need a vessel into
which to store the grey water,
typically an underground tank
fitted with a sump pump.
While shower and bath water
can be discharged directly into
the holding tank, kitchen
waste water should pass
through a grease trap first.
To use the grey water in one's
toilets will require a booster
pump fitted with either a
conventional bladder and
pressure switch or one of the
newer electronic controllers.
This should be fitted between
the holding tank and the toilet
cisterns and the float switch
on the sump pump in the
holding tank should be
adjusted to ensure that there is
always sufficient water in the
tank to allow for full toilet
cisterns.
The excess water from the
holding tank should be
pumped out by the sump
pump into a simple gravel,
sand and anaerobic filter
which, while it will not
remove the phosphates and
nitrates, will remove any
remaining fats, oils and
greases, and other solids such
as hair, skin and small food
particles etc that will have
escaped collection in the
grease trap. For it is these
small solids that, as they rot
and putrefy, make the water
smelly.
If you store the resultant water
in a dam or pond it will
quickly turn bright green as
the phosphates and nitrates it
contains provide nutrients for
algae to thrive.
This fluid can be used, not so
much as irrigation water for
the garden, as for liquid
fertilizer, be