Grey Water Treatment: How it works

Nature Clear provides an odour free method of filtering and cleaning grey water with no moving or electrical parts. The water from all grey water outlets flows into a polymer tank where it is progressively filtered and biologically cleaned. From the tank the treated water flows under gravity into an application area. The application area materials should be supplied and installed by your plumber. It may consist of trenches or 150mm sub surface irrigation depending on local conditions and regulations.

Because the dwell time of the water in the tank is short, there is no time for bacteria to build up as there is in anaerobic septic tanks. Consequently the system should be odour free.

Filtering of the water takes place in several layers of naturally occurring materials separated by progressively finer grades of geofabrics. A biofilm is established near the centre of the tank where aerobic bacteria clean the water. The resulting water quality is typically of secondary treatment quality.

There is no disinfection process and consequently most authorities will not allow the water to be disposed of above ground. Whilst it is unfortunate that the water cannot be disposed of above ground, no chlorination process has been used to disinfect the water. Please also note that during periods of drought some councils will permit the use of a diverter to allow discharge of the treated water at the surface.

If the application area cannot be fed by gravity, or the local authority insists on a pressurised irrigation system being installed, a pump well and submersible pump will be required.

The maintenance of the system is enhanced if a grease trap is installed on the kitchen waste outlet. Normal maintenance involves replacing the top layer of organic coarse filtration material twice a year and annual cleaning of the top two layers of geofabric. The old materials can be disposed of in your composting toilet or into a suitable area in your garden. The annual cost is less than $10. Using worms to clean the material for you can reduce the frequency of changing the top layer of material.