The Greywater Guide Resource Pack

Greywater is wastewater from baths, showers, spas, bathroom basins, washing machines, laundry tubs. Greywater is a resource that can be used to irrigate gardens and lawn, and for internal household use such as toilet flushing and laundry use when treated adequately. This alternative water source is important given the increasing demands on potable water supply from decreased rainfall and population growth. The benefits of using greywater as an alternative water source for both new and existing homes include reducing potable water demand, reducing wastewater discharge, reducing household bills and supporting a healthier garden particularly during the drier months.

This guide provides advice for the application of greywater reuse within households of the Swan Coastal Plain, however information is provided on the application within the heavier soils of the Perth Hills and regional areas in Western Australia (WA). The target audience is broad and includes developers, planners, architects, builders and the general public.

Included in the guide is information on: greywater and its benefits; regulatory guidance (in particular the ‘Code of Practice for the Reuse of Greywater in Western Australia’ (Department of Health, 2010); types of greywater systems and technology; application, landscape and irrigation considerations for implementation; design and technical considerations; indicative costs; installation and maintenance advice; water quality; greywater use in regional areas of WA; and including greywater in planning and design.

Case studies and working examples are interspersed within the guide, to provide direction on greywater reuse considering the prevailing residential building market, retrofit, location and regulatory constraints.

Purpose of the West Australian Greywater Guide

The West Australian Greywater Guide is a source of practical information on how to best reuse domestic greywater in Western Australia. The principle focus is sewered urban areas in the Swan Coastal Plain as this represents the majority of applications. Some information is provided on the application within the heavier soils of the Perth Hills and regional areas in Western Australia (WA). The information contained in this Guide is relevant to a broad audience including developers, planners, designers (consultants, architects and landscape designers/architects), builders and plumbers, homeowners, state and local government agencies.

Stakeholder benefits

Developers

Developers who incorporate greywater reuse into their project will be contributing towards Water Sensitive Urban Design (WSUD) outcomes through a reduced reliance on scheme water for garden irrigation. In addition, projects may be eligible for credit towards certain sustainability rating schemes such as the Waterwise Development Program.

Consultants, Architects, Landscape Designer/Architects

Greywater reuse can attract credits towards a development’s sustainability rating as it promotes best practice water efficiency and can enhance urban greening and cooling. It reduces the amount of scheme or groundwater required for landscape irrigation, demonstrating a commitment to current best practice environmental design for both the client and local community.

Builders and Plumbers

Builders and plumbers can play an important role in the uptake of greywater reuse
when interacting with clients as their recommendations can impact on decisions to install a greywater system. Greywater reuse is likely to increase in popularity due to climate change and provide a commercial opportunity for industry.

Homeowners

Homeowners who choose to install a greywater reuse system will have an alternative water source for their gardens that can be used outside of restrictions and will reduce their water bill. As with rainwater tanks, a greywater system can increase the resale value of a property and will also appeal to those wishing to make a commitment to saving water without sacrificing the health of their garden.

Acknowledgments

The West Australian Greywater Guide has been developed by the Greywater and Wastewater Industry Group Inc. (GWIG) and Josh Byrne & Associates (JBA) with financial support from Water Corporation, Department of Communities, Department of Water and Environmental Regulation, and LandCorp.

THIS DOCUMENT WAS PREPARED FOR WATER CORPORATION BY JOSH BYRNE & ASSOCIATES
Images, graphics and designs provided by Water Corporation, GWIG and Josh Byrne & Associates.