Paul and Nicholas Truong of Veticon, Australia have come up with a relatively simple and fully tested model for calculating the number of vetiver plants required for treating waste water and sewage effluent. The model will be particularly useful for individual domestic waste water treatment and small scale community needs. The model was initially designed for small Colombian farmers who need to treat the effluent from their coffee processing plants. The paper https://www.vetiver.org/LAICV2F/2%20Environmental%20Protection/E1Truong_TE.pdf describing the model, and the presentation https://www.vetiver.org/LAICV2F/2%20Environmental%20Protection/E1Truong_PpE.pdf that goes with it also contains images of various layouts that might be used. For further background on waste water management using the Vetiver System see this paper https://www.vetiver.org/LAICV2F/0%20Plenary/P3Truong_TE.pdf and presentation https://www.vetiver.org/LAICV2F/0%20Plenary/P3Truong_PpE.pdf. Thank you Paul and Nick!! This work of the Truong’s should be widely shared, and should be particularly useful to communities throughout the tropics or where vetiver can be grown.