An on-site recycled water system is a system that allows for the reuse of greywater or all wastewater (greywater and blackwater) from a site; this includes sewer mining. This alternative water option is only available for multi-unit developments within the BASIX tool.
BASIX assesses central on-site recycled water based on:
- Supply volume of the central recycled water system
- Uses of the recycled water, which need to be nominated separately under central systems and as well as under the individual dwellings, if applicable
- Areas of common landscape supplied by the central on-site recycled water system
Note: On-site recycled water systems require approval from the appropriate consent authorities.
Depending on the level of treatment, recycled water can be used for garden irrigation and some internal uses. The treatment of wastewater must meet relevant treatment standards. All forms of greywater/wastewater are capable of transmitting disease.
The potential uses of the recycled water produced by the central on-site recycling system is determined by the type of wastewater being collected and by the treatment system being operated. Recycled water should not be used for filling swimming pools and spas or for watering edible plants.
On-site recycled water systems should not be used for garden irrigation in areas identified as having major limitations to on-site disposal. Such areas include locations with shallow water tables, highly porous soils (such as sand beds) or with visible signs of surface dampness (such as seeps, soaks or springs).
Some other limitations that must be assessed before adopting greywater/wastewater reuse include soil characteristics, salinity and contaminant loads of wastewater, and the appropriate scheduling of application.
It is necessary to maintain sewer connections to provide an alternative disposal option in the case of on site system failure.
Further information and guidelines on wastewater reuse systems is available from the NSW Department of Health.