File:Vertiva grass used for constructed wetlands (3449814014).jpg

English: SITE CONDITIONS: The existing UDDT on the plot was constructed by the NGO Practical Action in the end of the 1990ies. It is not in use anymore, since the person responsible for maintenance of this UDDT (emptying chambers and composting in the adjoining garden) had passed away. Additional pit latrines were installed instead. The plot has also shower facilities for a total of 100 persons (25 households each 4 persons). Water is constantly available through a house connection with tenants receiving about 4 jerry cans per family each day from the landlord. The grey water runs openly, undirected and un-used in the on-plot garden. INTERVENTION: The ROSA project has proposed and agreed upon the set-up of a grey water recycling unit for production of irrigation water for the plot-garden. The grey water from old and newly constructed showers (added with rain water harvesting) as well as a hand-washing facility is discharged in a twin-chamber settling tank and overflow into a horizontal-flow wetland system with Vertiva grass, which is water-tight to the underground. The system is designed for 10 liter grey water per person and day. Retention time in the settling tanks is about two days and in the wetland three days. Floor slope of the wetland is 2 percent. Local available material is preferred in terms of pricing and accessibility such as local sand. The Vertiva grass can be used as fodder grass and is a decorating component. The complete system (including material, supervision, and transport) costs about 85.000 KSH.