Subject: (fwd) Re: Grey Water

From: [email-masked]
Date: Mon, 12 Feb 2001 01:16:52 -0500

On Sun, 11 Feb 2001 21:15:02 GMT, in alt.permaculture "Reedbed"
<[email-masked]> wrote:

gardenlen <[email-masked]> wrote

> the dimensions of the reed bed will all important, and as i see it you
> shouldn't need any prefiltering for shower and laundry water, kitchen
> water can be used you just need to run it through a grease trap first.

Hi Paul, Len's said pretty much all I'd say on the matter.
Greywater is low in BOD and pathogen content, and so you're not at
risk of
polluting anything by just playing around with whatever fits in the
space...
I'd use a vertical flow reed bed as the first stage - basically this
is a
liner, water tank or plastic barrel filled with different grades of
gravel
in layers - big stones at the base for drainage and sharp sand on the
surface. The effluent floods the surface, flows quickly downwards and
away
to the next stage, getting aerated in the process. (ammoniacal N is
converted to nitrite)
Next, a sub-surface flow horizontal bed would convert the nitrite to
nitrate, which is then easily taken up by plants. The HFRB is a
shallow
lagoon filled with gravel. Effluent entering at the inlet end
displaces
cleaned effluent at the other end, and the bed always contains water
to just
below the gravel surface.
I wouldn't worry too much about sizing the beds - it's more a case of
fitting them to whatever you have at hand for lining them. (This would
be a
different matter if you were submitting a design for Building
Regulations
Approval etc - but in that case you'd really need to pay someone, and
I
don't suppose the job would cover my travel expenses :-)
If anything, you run the risk of providing too little nutrient to the
plants, rather than too much, in a greywater system.

After that, your water will be crystal clear, and you can add any
ponds,
marsh areas etc. Water from a living pond is the best stuff for
watering
food crops, so I'd forget the idea of overflowing to sewers etc, and
put in
enough storage in the final pond to water the garden, as Len
suggested.

I won't go into planting, since some of the native plants we use here
in
Ireland are (according to other alt.pc'ers) noxious weeds downunder.
Just
look around for whatever grows wild in wet areas - the most useful
plants in

reed beds are all Graminae (grasses) - reeds, bulrushes etc.

Our website gives a little more background info -
http://surf.to/NaturalTechnology and there are loads of resources on
the web
covering reed bed construction - you can't get into trouble if you're
only
treating greywater - but of course blackwater would be another matter.

HTH
Mark

From: "Haig" <[email-masked]>
Newsgroups:
alt.hipcrime.engr.wastewater,alt.permaculture,alt.wastewater,aus.gardens,canb.general
Subject: Re: Grey Water
Date: Sun, 11 Feb 2001 21:22:31 GMT

Paul

Len is spot on about the size of components. I suspect you would need
a
fairly big reed bed or other nutrient removal scheme to do it. Then
there
will be the nutrient imbalance problem. Lotsa phosphates in cleaning
products but no nitrogen. So the removal bed will only clean up as
much P as
the N will allow, then you will be stuck with high P in your system
just
waiting for some nutrient input to cause an unexpected bloom...
probably of
an unacceptable type like blue-green algae. Could add N I suppose but
the
bed would need to be bigger. It really is requiring monitoring and
design
beyond just a simple DIY project.

Then there are the microbiologicals. Most local authorities ban any
sprinkling of grey water due to pathogens. I suspect they will see
cascades
as having similar tho reduced problems.

As Len says, the better option seems to be to use the grey water for
soakage
watering of plants and the water you save, augmented with stormwater
could
go into your system for make-up.  If you design as impermeable a base
as
possible for your feature, make-up will only have to cope with
evaporation.

Good luck, Jim Haig