Source: Laura Kraft Date: Oct. 2009 In the picture (left to right): James Raude, Caroline Wangeci, Laura Kraft Greywater treatment system in Crater School Secondary School (Nakuru, Kenya) implemented by the ROSA project. The greywater should be reused in the agro-forestry activities. Therefore samples of inlet and outlet were taken weekly and analysed for different physicochemical, microbiological parameters and nutrient concentrations to show the performance of the system. This was achieved by single pass treatment of greywater through a horizontal sub-surface flow constructed wetland (horizontal SSF CW, or HFB for horizontal flow bed) with Vetiver grass (Chrysopogon zizanioides L) as aquatic plants.