ModelGuidelines for Domestic Greywater Reuse for Australia

ReportNo WSAA 107

March 1996

SYNOPSIS

Thisreport is the third in a three part research project. Its purpose is to achievethe project’s final goal of formulating model guidelines for the regulation ofgreywater re-use systems in Australia; that is, those systems which re-usedomestic greywater from sewered premises. Domestic greywater is defined as thatwhich is derived from a non-industrial source.

Thefirst part, “Domestic Greywater Re-use: ThePreliminary Evaluation (UWRAA Research Report No 60, 1993)”, was completedin 1993. It included:

·        Overseas correspondence

·        a literature search

·        chemical and microbial analysis of some sullage systems

The report concluded that:

·        the western states of the USAand Japan are the world leaders in this type of onsite re-use

·        greywater re-use posesenvironmental and health concerns but, with adequate guidelines, could achievesubstantial water savings.

The second part, “Domestic Greywater Re-use: Overseas Practiceand its Applicability to Australia (UWRAA Research Report No 73, March 1994)”,was completed in 1994. This report investigated overseas practices in greywaterre-use and how this could be applied to Australia.

It is intended that this report,“Domestic Greywater Re-use: ModelGuidelines”, will assist Australian water and regulating authorities inmeeting the challenge to fully utilise this valuable resource without:

·        Compromising public health,

·        causing detrimental impact tothe environment or

·        down grading the livability ofour residential areas.

The report covers:

·        Surface Reuse

·        Sub-surface reuse

·        Storage of greywater

·        Chemical content

·        Hand Basin Toilets

·        Toilet Flushing

Conclusions

The report proposes modelguidelines should the re-use of domestic greywater become legal.

However, caution must beexercised when introducing greywater re-use because of the undefined increasein risk to public health and the environment.

We live in a society that has arelatively healthy population with little natural resistance to most water,mosquito and vermin borne diseases. The sanitary sewer has been one of thefundamental measures which has improved health in the developed world and anychange from the current status must be such as not to compromise the gains inpopulation health which have been achieved.

Infectious disease epidemics canoccur once disease is introduced to the non-resistant population and has a modeof transmission. Any decision to change the present sanitary practices needs tobe seriously considered .

Copiesof the Report are available from WSAA, price $A40. Orders may be placed throughthe Bookshop at www.wsaa.asn.au or by email to info@wsaa.asn.au.