All the waste water from the house drains to a septic tank and from there into a 2m x 11m x 600mm reed bed. This is sealed with a plastic liner, and filled with coarse gravel to 150mm above water level, and planted with about 100 reeds of two species (Baumea articulata and Leperonia articulata). However there are a wide variety of wetland species that are effective.
As the reed bed slopes very slightly down towards the outlet, the sewerage takes about 11 days to migrate from inlet to outlet, during which it is broken down by the bacteria living in the root zone of the reeds.
The water then collects in a sump and is pumped underground to a grid of perforated pipes under the orchard area.
In Queensland it is completely legal to pump the outlet of a reedbed system directly onto vegetables, but in NSW it must be discharged underground.
We find the system never smells, and is very low maintenance, with the only chore being to cut down the reeds every few years. If you have a sloping block it can be set up so no pumps are used, though that was not possible in our situation.
Apparently reedbeds also cope rather better with variations in input (for example a long holiday or multiple guests) than the worm farm based systems. However any of these are in my opinion better than the Envirocycle type aerated systems.
Our system was designed by Geoffrey Love of Domaine Environmental (domaine@midcoast.com.au) and the reeds were bought from Bluedale in Wauchope (http://www.bluedale.com.au/)
