WHAT TO DO WITH
Following is general information on Greywater
. For a design and quote for a Greywater
RE-USE System for your situation please
e-mail me so that we may discuss your System further.
A Greywater Re-Use System is a grey water
system designed to treat domestic wastewater excluding toilet waste.
Councils are increasingly reluctant to allow homeowners to dispose of
grey water without basic treatment. The days of being allowed to spray
wastewater untreated onto the garden are over. Each State and Council
have their own regulations and you will need to contact your local
council to establish what they will permit alongside a waterless toilet.
The following explains the situation primarily in NSW. Please note
however that there are variations from State to State & from Council to
Primary treated wastewater must be disposed of in sub-surface trenches,
or evapo-transpiration (ETA) beds. Septic tanks are the main example of
systems that treat only to the primary level. Secondary treated water
can be disposed of below ground, for example, by drip irrigation lines
under mulch. Disinfected secondary treated water can be disposed of at
ground level and in some cases by spraying in pre-designated areas.
Aerated Water Treatment Systems (AWTS) treat to secondary level. Such
systems include a disinfection unit, most commonly using chlorine. These
systems typically cost around $8,000 plus in ground installation. There
are then annual inspection and maintenance fees plus wear and tear on
the pumps and aerators and electricity costs totalling some $800-1,000
or more per year.
In order to satisfy the Australian Standards (AS1547) requirements a
grey water re-use system which cleans waste-water via a grease trap and
gravity fed primary treatment can be used. You can use the Greywater
Re-Use System for disposal of the water via trenches, shallow
sub-surface irrigation, or ETA beds.
Suggest the Greywater Re-Use System to your geo-tech engineer and/or
Your council will probably ask you for a site plan. You may need to
engage a Greywater Re-use Design consultant or geotechnical engineer to
test your soil and produce a plan for distribution of the treated water.
Make sure the consultant or engineer allows for the lower volume of
water associated with a waterless toilet. This should result in an EDA
(Effluent Dispersal Area)
only 65% of the EDA for septic systems or AWTS handling both
black (toilet) and grey water.
We have found that some consultants & engineers have not had experience
with composting toilets and so may not want to design a system around a
waterless toilet. You should check before engaging anybody that they are
happy to work with you in designing a system which is based on waterless
The Greywater Re-Use System is explained below.
The Greywater Re-Use System provides a simple and low cost effective
means of treating grey water. Not only is the equipment low cost, but
also, if your site is suitable, the only excavation work required to
install the system will be the trenching. The ongoing costs will be less
than those of a standard septic system.
The filtration tank, which is less than 1 cubic meter in size, consists
of a pine bark coarse filter on top of a Bio-Mass filter. The coarse
Pine Bark filter removes large particles & fats from the kitchen, and lint from
the washing machine normally caught in a grease trap. Compost worms can
be used in this layer. The filtered material and bark will compost over
time and should be removed every 6-12 months and replaced with fresh
bark, available form your local garden nursery. The pine bark is
separated from the Bio-Mass by filter cloth. The Bio-Mass filter treats still
finer materials, converting the organic content of
the water into water soluble nutrients that can be used by your trees
and plants. The final stage of primary treatment to is flowing over the
bio-film on the 20mm aggregate at the base of the Greywater Re-Use
System tank. If your distribution area is down hill from the filtration
tank your engineer/consultant should be able to design a distribution
system without the use of a pump. If this is not the case you will need
a pump well.
Adobe Loos & Worms can prepare a Greywater
Re-use Design that is suitable to submit to
Council. The Design will include a Specification and Schematic Plan of
the System, a Water Balance and Components listing. If you require
us to do this please contact us for a quote on design costs starting
given above is offered only as a guide. We recommend that you seek
advice from your council plumbing inspector, but do not be deterred from
your decision to use a composting toilet unless the inspector can
identify in writing why it is unsuitable for a particular location.
In NSW you
can submit for Council approval your own greywater
system using a Greywater Re-use Treatment System for use in connection with
subsurface irrigation. See
NCG System &
NCP System for
Q: Your Waterless Composting Toilet will keep
polluting & wasting precious water by flushing it away. But what about
the rest of the water you use? How can you make the most of it, rather
than just using it once to wash your dishes, or your clothes, or
A: Clean your greywater
and use it again to quench your garden's thirst.
Q: How do I clean my greywater
Read on to:
Greywater Re-use Treatment System
Greywater Diverter System