All rubbish trucks that bring waste to the Tamala Park landfill have the opportunity to have there trucks washed before leaving. The system used to treat the run-off from the trucks is called the Vetiver Treatment System and its role is to minimise any impact of the run-off on groundwater.
- Truck wash water is collected in a concrete hardstand area and channelled towards a large steel bin that has been modified to capture solids whilst waste water flows through. Captured solids in the steel bin are removed, drained and then emptied into the landfill cells on a weekly basis.
- Waste water flows into a concrete 50kl primary settlement tank with a 2-3 day retention time where finer particles are settled out and oil and grease are floated off. This is pumped clean annually.
- The waste water flows into a 550m2 lined Vetiver System. The Vetiver Grass within this system reduces the nutrient loading of the waste water. Evapo-transpiration processes also significantly reduce the volume of water requiring discharge.
- The water is then passed into one of two parallel Ecomax beds which are designed to strip phosphorus. In winter the two beds may be run in parallel to cope with winter loadings whilst in summer one is left to dry out and rejuvenate. Sedges planted in the Ecomax help remove any remaining nutrients and remove water through evapo-transpiration.