There is support for conservation of quality drinking water resources, whilst disposal of society's wastewater requires the provision of wastewater treatment and disposal systems, the size and cost of which to construct, maintain and operate is affected by a number of factors including the volume of wastewater to be treated and disposed of.
Graywater (spelt greywater in Australia) is generally considered to be those components of domestic wastewater that have originated from the laundry, bath, shower and hand wash basins. Whilst these streams of wastewater contribute significantly to the total wastewater volume, they contribute little to the organic content of wastewater and thus need only minimal treatment for garden irrigation. However, as untreated graywater is wastewater which contains suspended organic material and the same micro-organisms as found in toilet waste, albeit in lower concentration and numbers, the regulators of plumbing and health standards ensure graywater reuse and the associated plumbing works must occur only in an acceptable manner.
A number of graywater reuse systems and products have previously been developed and promoted, but these have not been particularly successful or accepted because they either:                could not satisfy the established standards demanded by the regulators of plumbing and health law and codes to be approved, and were typically illegitimate ad-hock plumbing type configurations consisting of a variety of components including valves connected to flexible hoses, rubber funnels, cloth/stocking filter bags, modified water barrels, and other temporary type components and most provided little or no contingency against failure and human exposure to the graywater or sewer gases, or;        are acceptable to regulators but are too expensive for domestic users to purchase, operate and maintain compared to the value of water savings, and are typically large below ground treatment tank systems consisting of septic tanks, aerobic treatment systems, sand filtration systems or other treatment type systems that incorporate disinfection, pumps to lift the water back to the surface, failure alarms, sewer anti-backflow fittings and other components which generally add significantly to the overall cost and such systems generally require ongoing maintenance contracts to be entered into by users with licensed contractors.        