In using a Rota-Loo Composting Toilet, the toilet wastes are kept separate from the grey water (sullage) which is the water which comes from the bath, the shower, the laundry, the kitchen and hand basins. It is easier to treat this greywater as it has fewer disease organisms, it contains less nutrients and solids and is considerably lower in volume than septic or aerated systems.
Both the Rota-Loo and grey water systems are self-contained, and have been approved by the E.P.A. as appropriate on-site systems of disposal. Therefore you will not need to deal with less efficient, water borne and polluting system.
In average soil conditions, we would expect the need for two 10-12 metre trenches to be used alternately. These could vary in length depending on the type of soils, and the maximum number living in the home. This is covered in more details with the Trench Drawings. These detailed Trench Drawings are included with each tank sold.
These trenches reduce the concentration of nutrients and pollutants in the grey water to negligible quantities. The principle of operation of these designed trenches is to keep the waste water in an aerobic state near surface of the soil where there is a high population of soil microbes and other soil animals such as worms. This soil fauna is very efficient in digesting the nutrients and pollutants in domestic wastewater to reduce the concentrations to negligible and often to undetectable levels.
The Niimi Absorption Trench and Rock Plant Filter systems are approved by the Environment Protection Authority, pursuant to Section 53M (7) Environment Protection Act 1970. Certificate of Approval CA 041/94.
In Western Australia the Rock Plant Filter systems are not approved and should not be used. However the Niimi trench is, with slightly different conditions to the rest of Australia.