Where do you go to the toilet when you live in a floating home? Over 100,000 people live on Tonlé Sap Lake in Cambodia. Many people use the lake as a toilet, the same lake that they use to wash dishes and clothes and that children swim in. The original idea was to collect the raw sewage in a floating drum which anaerobically begins to treat the raw sewage (as in a septic tank). From there the raw sewage is directed to a floating pad of water hyacinths. Microbes around the plant roots break down harmful substances further before discharging into the lake. Putting this idea into practice threw up several challenges.
Firstly, unprecedented dry weather in 2015 meant that floating households that had never been land-bound before had no choice but to pull their dwellings onto the shoreline as tributary water levels dropped to record lows. People were reluctant to spend their dwindling incomes on sanitation systems, and the design had to be modified to be ‘amphibious’ to cope with the dry conditions, rather than being targeted for dwellings expected to be permanently afloat.
Wetlands Work! designed and constructed a new prototype, which replaced the floating section of the system with a treatment system firmly attached to the dwelling. Such a system can float with the house, or work equally well on land as required. The modifications eventually led to a more robust system with broader applicability. The new design has significantly longer life use, is stable in extreme storm events, is easier to build, requires minimal maintenance, and performs substantive wastewater treatment in both floating and dry land environments.
Systems were designed and installed in schools, and a savings scheme set up. It will be interesting to see the progress in another couple of years. More information here.