Greywater FAQs

Why is an irrigation system better than just using a hose from the washing machine, or buckets from the shower?

An irrigation system ensures the greywater is evenly distributed across the entire garden area.  This is much better for the garden as any contaminants in the water are spread across a wide area.

Using buckets and / or hose typically cause the following problems:

• Over watering in selected areas, while other garden areas remain dry
• Contaminants (salt / phosperous) building up in a small area near the laundry, resulting in poor plant performance
• Washing machine pumps failing because the are not designed to push water through long lengths of corrugated hose. Cheap greywater hoses available at hardware stores really are false economy. The hose is ridged on the inside as well as the utside, so any undissolved detergent catches in the ridges, and over time will build up and reduce the capacity of the house - similar to blocked arteries.
• While excercise is good, manually bucketing water from showers is likely too cause skeletal and muscular issues over time. From a water saving perspective, catching water by buckets is very inefficient - more water goes down the drain than in the bucket!

Can I use my existing garden drip system?

It is possible to re-use your existing drip system, so long as it does not use sprinkler or misting outlets. It will not work anywhere near as well as a proper greywater drip line.

Potable water irrigation and greywater irrigation are  entirely different concepts:

• Potable water (from the mains water supply or tank) is limited in supply - therefore watering is limited to perhaps twice per week. In most cases, particular plants are targetted to receive more water. Over summer significant amounts of water are used to keep the garden alive between watering sessions. 
• Potable water drip systems irrigate at the rate of 3 L / Hour per dripper. Drip lines / drippers are placed alongside plants, or generally every 30cm along the garden bed. 100 Metres of standard drip line will only irrigate at  14 litres per minute.  The drip lines are sensitive to contaminants in the water, and require an additional filter be fitted to the EcoBowser. This filter will require cleaning every week (very fine filter). 
• Greywater from showers is used to irrigate the garden every day. Instead of targetting specific plants, the goal is to acheive moist soil across the entire garden bed. So long as the garden bed is not over watered, plants will soak up the water based on individual needs.
• Greywater drip systems irrigate at the rate of 8 L / Hour per dripper. Drip lines are placed every 1.5 metres. Each dripper has its own mini filter. After passing through the primary EcoBowser filter, small particles remain in the greywater. These particles try to exit through the dripper, are rejected by the dripper filter, and pushed back into the drip line. The particles remain in the tubing until the whole system is flushed by operning the end of the drip system and flsuhing with either potable or greywater.

Greywater drip systems can be used for potable water as well as greywater. As potable drip and grey drip is approximately the same cost per metre, greywater dripline is much cheaper, as only 1/3 meterage is required.

For peace of mind, and minimal maintenance requirements, greywater dripline is strongly recommended.

Is there a way to store greywater?

Yes, if the water is treated. The cost of treatment systems ranges from approximately $10,000 to over $15,000. In addition maintenance of these systems is required, typically $1,000 per year.

Most households generate sufficient greywater for the garden every day, as a result there is no practical need for storing greywater.

Can I re-use greywater in the toilet cistern?

Regulations do not permit re-using greywater anywhere within the house without treatment (again $10,000—$15,000)

If you want to reduce your potable water consumption as much as possible, we recommend installing a greywater diversion system for the garden (such as the EcoBowser) and a 2,000+ litre rainwater tank connected by a plumber to the toilet cistern / clothes washing machine.

What about the new desalination plant for Melbourne?

The desalination plant will not be producing water until 2012/2013.

• Water will cost at least twice as much than now (if not more).
• Re-using greywater on the garden will save the average gardening household $450 per year now in reduced water consumption. This saving will rise to $650 upwards (or more) per year by 2013/2014.
• Desalination plants are energy intensive, and have massive carbon footprints. If we are serious about sustainability, potable water should only be used where it is absolutley required for hygiene reasons - not wasted on gardens when greywater is an acceptable alternative.