Greywater is safe

Always use a professional installer with greywater experience.

An experienced greywater professional should always be used to design and install a greywater system. GWIG can provide details of qualified greywater professionals.

How to maintain pump and dripline

A reliable and effective greywater system depends on maintenance and protection of:

The pump against clogging due to debris in the greywater – typically hair and lint, but also other solids washed down the drain.

The dripline, to ensure solids don’t enter and clog the emitters (drippers) – either suspended in the stream of pumped water or sucked in from the surrounding soil.

Maintenance is most effective when undertaken in partnership between the owner and the installer. The installer can advise on the frequency of inspection and maintenance depending on the components of the specific unit.

Soil and plant health inspection

The nutrient content of greywater, primarily nitrogen and phosphorus, can benefits many garden plants growing in Western Australia’s nutrient depleted soils. Plants and soil should be regularly inspected to ensure there are no signs of deterioration from use of greywater.

Diversion to sewer

A greywater system must be able to divert to the sewerage system to ensure low quality water is not used on the garden or to avoid over-watering during winter.

Water quality and household product selection

Greywater is water from the shower and bath, basins and washing machine and may contain soap, hair, lint and household cleaning products. Despite this, it is still a suitable source of water for irrigation. It is important to ensure the greywater system is switched off and flows to the sewer, not the garden, when washing nappies, if someone is sick and when high levels of chemicals are being used.

Residents with a greywater system should always use “eco”, “garden-friendly” or “greywater friendly” products that are biodegradable and also low in salts and phosphorus. Bleaches, disinfectants and strong chemicals should not be used as they kill beneficial soil micro-organisms. Using greywater-friendly products minimises the potential negative impact that greywater can have on some plant species, in particular to some WA native species, and soil types. Periodic inspection of the health of plants and soil receiving greywater is always good practice and should be part of a maintenance regime.

Certain elements in greywater can cause problems, such as having high levels of alkalinity from soaps and detergents and using products containing Phosphorus and Nitrogen. Using the correct amount of liquid detergents containing no phosphorus, turning off the greywater system in winter and increasing soil organic matter can combat issues caused by high alkalinity and Phosphorus.

About The Author


Greywater & Wastewater Industry Group. We are a group of water industry professionals who are active in the design, research, manufacture, installation and servicing of greywater and wastewater treatment systems. GWIG is a non-profit organisation which was formed in late 2010 in order to provide a united voice for a WA industry that is largely unsupported and under-acknowledged for the important work that it does.