Any details, information or experiences on low water volume flush toilets?
In water stressed area using a lot of water for flushing may not be possible or practical. Ecological dry solutions lack the necessary aspirational qualities. Low volume flush may be the answer.
Ceramic pans(Goose necks) are surely providing one of the much needed solutions in upgrading latrines in peri-urban or low income areas(LIAs) of Blantyre. To get a customer-feedback on ceramic pans, recently we visited one customer who bought a ceramic pan from an entrepreneur in Bangwe township (one of the low income areas of Blantyre) and this is what Mrs Matola had to say, "due to inadequate space, we have our latrine close to our house(about 3 meters). With the white ceramic pan on our latrine, there is no bad smell, no flies and i can leave the latrine door open without being ashamed when visitors are around". The customer sentiments above provide an insight to the desires of a huge number of households owners/tenants with latrines requiring this upgrade in the densely populated low income areas of Blantyre. Supporting entrepreneurs with intensified promotions/marketing on upgrading latrines in LIAs will be ideal.
There was a pilot project carried out by the BRE in Botswana which was reported by Swaffield and Wakelin in Low Cost Sewerage Ed DD Mara, Wiley, 1996, now out of print. This involved installation and monitoring of ceramic pans manufactured by Twyfords and were designed for a 3 or 4 litre flush I think. Interestingly Twyfords now market a similar 'rimless' design in the UK with a dual 4/2.6 l flush.
Ifo Sanitar developed in the 80's a 1.5 l flush pan which was marketed in Sweden for on-site systems, but not licensed for connection to a public sewer, but their website no longer mentions anything of the sort. However they do have an 4/2.6 l pan marketed by the Green Building Store in the UK.
There was a firm in South Africa that were manufacturing rotation moulded LDPE WCs I think they were called Watergate, but unfortunately they seem to have disappeared. I met the founder when he was trying to sell plastic pit latrine thrones to a project I was working on in Swaziland. I suggested that he modified his WCs, which were very robust and quite cheap, by reducing the diameter of the outlet and the volume of the trap. He went back to South Africa and phoned the next morning to say he had mocked up a low volume pan overnight and was terribly excited about how he could flush newspapers away with a couple of litres of water. I think that this shows that it is probably quite easy to design a pan that will work adequately, if not optimally, without huge amounts of development and testing. The problem is more in the manufacture and marketing.
I subsequently imported a container load to Zimbabwe which were installed in Bulawayo. I have no idea what has happened since then, which was more than 15 years ago.
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