Rental Property – Greywater retrofit in White Gum Valley

In this case study a greywater reuse system was installed at an existing single story,
 three bedroom, one bathroom family home. The building was a brick-on-concrete slab construction on a 600m² block in White Gum Valley, Fremantle.

The owner gave consent for the tenant (2 adults and 1 child) to retrofit a greywater diversion system to provide irrigation for a renovated backyard garden. The system was configured to collect greywater from the bathroom and laundry.

The greywater system forms part of
a larger comprehensive water efficient design approach to the house and garden which includes hydro-zoning and a plumbed 2,500L rainwater tank (to toilets and washing machine). The garden won the Sustainable Residential Category at the 2011 WA Landscape Industry Awards. The system was monitored in order to quantify the volume of greywater dispersed to the garden over a period of nine months.

System make and model

GreyFlow PS Plug’n’Play by Advanced Wastewater Systems. This unit includes an automated filter backflush system to minimise routine maintenance, whereby air is regularly blown through the filter pads to dislodge hair, lint and other debris that may clog the filters over time. The submersible pump stops whilst the blower is operating so that incoming greywater flowing across the filter pads washes away the dislodged debris into the sewer. During this process some greywater capture is lost but the need for manual filter cleaning is all but eliminated.

Irrigation area

Greywater dripline was laid out over an area
 of 40m². The garden irrigation was automated by a multi-station programmable controller, which also operated a dedicated greywater
‘top up’ line to supply water to the greywater hydro-zone for periods when the house was unoccupied and irrigation was required, or when greywater volumes were inadequate to meet plant water demand.

Cost of installation

Approximately $2,150 which included the plumber’s charges and excludes excluded power point installation. The City of Fremantle refunded the standard local government fee ($200) upon a final satisfactory inspection.

Approvals process

Approximately six weeks for all local government approval processes, half a day to install greywater unit with all plumbing and electrics and one day to install the irrigation system.

 

3 person Household used 100,000 Litres less than suburb average

GW – Greywater
RW – Rainwater
MW – Mains water

Outcome/Water savings

The system was monitored for nine months and the water savings achieved by the integrated approach to water efficiency, rainwater and greywater when compared to the local suburb and Perth average is shown in the graph above.

I love using Grey water in my garden because it allows me to minimise the use of scheme water in our garden watering regime with only small changes to the type of cleaning products we use in our laundry and bathroom. It also allows me peace of mind every time I take a shower knowing the water isn’t just going down the drain but directly into my beloved garden. 

Andrew Beck
Sustainable Garden Design Perth

Having Greywater go to my garden means my plants get watered every day of the year when I’m home. The water savings in summer are huge. Installing a greywater system at my own new build was a must, along with a Rainwater tank. Putting these systems in during the build process is easy compared to retrofitting, and generally cheaper. ‘Water Capture’ sell, install and service Greywater systems in Perth. 

Mark Harland
Water Capture

WaterCraft service a lot of greywater systems across the metro area and see many gardens thriving on the use of greywater. Frequent watering with traces of soap and nutrients works really well for plants on poor sandy soils. But just as you wouldn’t expect your mains water retic system to run for years without any attention, don’t expect your greywater system to keep running without a service!

Gareth Almond
WaterCraft

About The Author

Josh Byrne & Assoc.

JBA is a Fremantle-based consultancy providing integrated services across landscape architecture, environmental engineering and sustainability, community engagement and communications. We are recognised for being at the forefront of urban design innovation and are highly regarded for our commitment to projects that champion positive environmental and community outcomes.