Dec - 2006 Grey Water

With most of Australia currently experiencing varying stages of water restrictions there is a big push to use alternative water sources for residential irrigation. The simplest and most common method to date has been the installation and connection of a rain water tank and pump. Tanks are relatively cost-effective to install but face the issue of relying on rainfall to fill up. Grey water is particularly attractive because it's water that gets used by a household regardless of external conditions.

"Grey water" is the term given to wastewater from baths, showers, basins and washing machines. Although technically "dirty" water, grey water generally contains sufficiently low levels of contaminants that it is suitable for garden or lawn irrigation via sub-surface distribution. The wastewater generated from kitchen sinks, toilets and dishwashers is normally referred to as "blackwater" and is not suitable for reuse.

Presently almost all grey water from Australian households literally goes straight down the drain. Sydney Water estimates that in an average household of 3-4 people, this represents approximately 400 litres of grey water per day that could potentially be used to irrigate the garden. So why aren't more people using it?

Different rules & regulations apply to the use of grey water right across the country. There isn't one single national set of grey water guidelines, which can make things confusing for consumers.
Different rebates apply in different states, but again there's nothing consistent in terms of who is entitled to what. Generally a licensed plumber is required to complete the installation to be eligible for the rebate, but it's a matter of contacting the local authority to find out the exact details.

Purple/Lilac products - used for non portable water

Purple/Lilac products - used for non-potable water

Nylex Greywater Diverta

Grey water generally isn't allowed to be stored for longer than 24 hours, meaning it either has to be dispersed immediately or some sort of timed discharge device needs to be fitted to any system that “stores” grey water.
There is a lack of truly cost-effective grey water products that actually work effectively. An end-user could pay over $5000 - $10,000 for a fully installed system that is computer controlled and has a treatment plant built in, but that's a lot more money than most people want to spend. The low-mid priced systems that are currently available are capable of 'diverting' grey water from the drain to the garden, but generally aren't good enough at dispersing the grey water through a drip system to adequately irrigate a garden or lawn area.

The main issue associated with the current systems is their inability to create enough pressure to effectively distribute the water via subsurface dripline. Most pumps in the current systems will only provide around 7m of pressure, where as something closer to 30m is more desirable to be able to facilitate a relatively long run of dripline while allowing for minor elevation change.

The good news is that the tighter restrictions are getting, the more seriously manufacturers are looking at coming up with effective grey water solutions. There are several exciting products that have either just been released or are anticipated to be released soon. Keep your eye out for these:

H2gro from PPI
Grey Flow from Your Water Saver
Greywater Diverta from Nylex Water Solutions

The key thing to remember when considering a grey water system is that every installation is unique. The best starting point is to contact your local water authority to find out specific rules, regulations and any possible rebates that apply in your area. The next step is to contact your local Reece Irrigation branch and provide as much information as possible about the setup of your house, the results you're hoping to achieve with your grey water system and your approximate budget. Our staff have the expertise to offer the best advice for each individual situation.