Etudes de cas
Low cost greywater treatment for households, Lilongwe, Central Region, Malawi
Draft - Case study of sustainable sanitation projects
This case study describes a first trial of a small-scale grey-water treatment box (reed bed) for urban and peri urban households in Lilongwe, the capital of Malawi. The project built a model of greywater treatment system installed in the house of a regular Malawian low-income family with four small children. It was an urban upgrading and/or low cost housing, individually- based sanitation, implemented in a pilot scale. Two treatment plants for 2 families were constructed in the Area 25, a Habitat for Humanity-neighbourhood. The project was planned by GIZ Malawi & Ministry of Lands, Housing and Urban Development, executed by GIZ Malawi & Green Water, Mombasa, Kenya with the support from Habitat for Humanity, Malawi
The project tested and demonstrated a sustainable low cost water treatment option for households to prevent standing greywater and clogging of soils. It also avoid open disposal of untreated wastewater into public space or to neighbour’s plots. The applied technology involves a simple manual collection of greywater. The resources to build this treatment system are: a defined box or impermeable area, sand, gravel, some water-loving plants, pipes, a plastic container and a sieve. A total of 80 EUR is required to construct a single unit of the greywater treatment system. No replacement is needed, except for the sieve every few years. The treatment box can be directly connected to a small scale irrigation system for domestic gardens.
The project is purposely limited to finding a cheap and effective domestic greywater treatment option applicable to both, upgrading of existing housing, and to newly built low cost housing. The system is appropriate in areas without a functioning sewer system and where septic tanks are not an option, either due to economic or environmental reasons. Besides, it helps protect the ground water because it promotes the separation of the greywater from pit latrines.
Sustainable Sanitation Alliance (SuSanA)
reed bed, grey-water, domestic gardening, irrigation, treatment box, Malawi
Ilberg, A. (2012). Low cost greywater treatment for households, Lilongwe, Central Region, Malawi - Draft - Case study of sustainable sanitation projects. Sustainable Sanitation Alliance (SuSanA).