Grey water treatment in sand and gravel filters. Manual for design, construction, operation and maintenance. Low tech solutions for sustainable wastewater management

Only 20% of global wastewater is currently being treated which is not only a risk to public health but results in a serious damage for ecosystems and water resources. Greywater is a major part of domestic wastewater and as it excludes toilet wastewater, greywater causes less hygienic risks and is easier to manage. Greywater can be a valuable resource for water reuse, for example in agriculture.

Grey water management is complementing sustainable onsite sanitation solutions such as an ecosan toilet. This manual explains how grey water can be treated in a sand or gravel filter before being re-used. Different grey water filter designs have been demonstrated in Georgia in two villages close to the Black Sea by the Georgian NGO RCDA with guidance from Lukas Huhn from Hamburg University of Technology. The technology is efficient, relatively simple, low-cost and can be realised by practitioners in rural and peri-urban areas of most settings.