How to make a DIY Nonolet
At the beginning of Water Year 2008 (also International Sanitation Year, UN) the BBC-World Service is broadcasting a 23 minute long item, taken at our location in Breskens, mainly about the Nonolet. This is why we felt the need to add a revised version of our DIY article on 'Beter 1x zien dan 100 x horen' on our site. The original article "Zelfbouw gft-toilet" was published in 2001 the year Sietz Leeflang invented the compost toilet which became known as the Nonolet ®.
The working principle of the Nonolet is based on the henceforth unknown fact that faeces covered with a high fiber paper which is pressed down is odorless within seconds. A plunger is used for this 'pressing down' made of a stainless steel disc which is slightly curved inwards. Not only does the pressing down diminish the smell it also reduces the volume. Any moist residue is absorbed by the tissue. This way a papier-maché heap develops which is impenetrable for urine. The fluid is drained away through the perforated biodegradable plastic bag which lines the container. A household consisting of four people will take two to three weeks to fill this bag, the contents of which can become a wonderful fertilizer after compostation. Whether you compost it on your own compost heap or add it to your garden waste bin for collection all depends on your local situation.
Emptying your Nonolet is a clean, hygienic and odorless activity; fluids are drained away through an opening in the container.
Not only is the functioning principle of the Nonolet simple, building your own is also quite easy.
The toilet should have a height of approximately 45cm and can be made of a wooden casing. The seat needs to be about 23 to 25cm wide and 28 to 30cm long, oval shaped.
The container (bucket) inside the casing has to join the seating seamlessly but not airtight (this is very important) and should be approximately 40cm wide.
The bag lining this bucket should be 70cm wide and 65cm long with perforations in the bottom 8-10mm in diameter. It is possible to order these bags from us but since shipping costs do add up it may be easier to find a supplier in your country of residence or create your own. To do this you simply fold a piece of plastic to above mentioned size, fold the sides tightly and staple. Perforate 20 small holes just above the fold. Obviously none degradable bags must be thrown away separately after emptying the contents onto the compost heap or garden waste bin.
In the bottom of the bucket (either made from plastic (polyethylene) or zinc) a hole has to be made with a diameter of about 15mm. This hole needs to be worked on with a tapered tool from the inside of the bucket so that a smooth outlet is created. If you are using a metal tool on a plastic bucket you can preheat the tool to 120-130 degrees Celsius and gently press it down.
To ensure the drainage of the fluid a shallow plastic bowl with a scalloped-edged rime is put face down to cover the hole (see above picture). For this purpose anything can be used from a dish used for plants to the sawn of bottom of a small bucket just ensure that fluid is able to get underneath.
The bucket is then placed on a wooden, plastic or rubber platform with an opening in it. The opening in the bucket should fit comfortably in this opening. The opening is then fitted with a metal/ plastic duct or a flexible plastic/rubber hose. With a diameter of 20 to 25mm this hose needs to be fitted airtight to the opening. This will be the urine drainage.
The toilet can and should work odorless, even when in use if you fit the toilet casing with an air duct which has a small ventilator at the end (where the duct passes through the wall or roof).
To prevent odor from the urine drainage it is important to use only metal or plastic. A rubber hose is not able to prevent a slight smell developing.
When using the toilet it is important to frequently throw a glass of water onto the heap. This will prevent urine sedimentation in the drainage system. The Asian way of washing instead of using toilet paper after using the toilet is a good option.