Dear Christoph,

Thank you very much for sharing your working situation...I feel sorry to focus on environmental aspect while it is probably unappropriate. I appologize to be out of the theme and hope the collection will work. Thanks again for sharing.

Geoffroy

DEAR ALL

THE IDEA OF POUR FLUSH TOILETS TO ME IT SOUNDS LIKE WE WANT TO BRING BACK WATER IN THE TOILETS , I HAVE A STRONG BELIEVE THAT A WATERLESS TOILET WILL BE THE BEST SOLUTION AT THE CURRENT MOMENT , LIKE IN SA WATER PROBLEM IS LONGER AN ISSUE BUT A MATTER OF LIFE AND DEATH, PEOPLE GLORIFY A HALF GLASS OF WATER SO IT WILL BE VERY MUCH IMPOSSIBLE FOR THE POOR COMMUNITY TO PUT 2L OF WATER IN THE TOILET, ABOUT THE GRAY WATER IT MEANS ONE HAS TO WAIT FOR ONE TO USE WATER TO BE GREY BEFORE HE/SHE CAN GO TO TOILET, WHAT ABOUT IF I HAVE A RUNING STOMACH IT MEANS I WILL HAVE TO COMPROMISE CLEAN WATER IF I DO NOT HAVE GREY WATER.
GOOD PEOPLE WATER IS LIFE WE TRY TO SAVE EVERY SINGLE DROP OF IT.LETS TRY TO SOLUTION WERE WE WILL ONLY USE AND HAVE DRY PIT IN A WATERLESS TOILET.

ROCKY


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Note by moderator (EvM) to Rocky: Please do not use all capital letters in your post as it looks like you are shouting! Also please still follow my request to introduce yourself, even if it is only a brief introduction. Thanks

Hi Sjoerdnienhuys

My understanding is that the sanitation system used in Zambia in the '60s was the Aqua Privy, a kind of latrine directly above the septic tank which did not use a P-trap of gooseneck type seal. At least I have seen drawings of this kind of design attributed to Zambia, and I have also seen a few in the field here in SA. What I do not like about that design is that if the pit is not water tight then the water seal is lost and then odours and insects become a problem.

Rocky

There may well still be places in SA where water is very scarce, but in my experience in KwaZulu Natal that is not the case. We are after all the country that came up with the concept of 6000 litres free water per month.

Okay , i will formaly like to introduce my self to the forum.
My Name is Masilu Rocky Malebogo ,stay in South Afrca in Pretoria,in working in a sunitation instutution as a project manager for sunitation project around africa at large.
MY appology for bagging in to the forum without introduction.

Dear Geoffroy,
Thanks for the understanding:
1) I am glad that you understood –and share - the point why urine diversion is not the first issue in these cases.

2) I think it is totally right to question the pollution aspect. We have always to think about this aspect and we have to question us again and again. And difficult situations do not justify hazardous contamination – and it is clear that the word hazardous describes a subjective view.

For me again the eThekwini people are getting it right.

[/ul]When there is no possibility for individual toilets – communal blocks

When there is room for individual toilets (without sewer) – UDDT

Now they are thinking about a collection service for the UDDT for feces and if there is commercial value, as well for urine. They consider the feces (potentially) hazardous (when not well buried) and the urine a potential revenue source (in future).

Christoph

Let me start by wishing everyone a great 2013 and beyond.

In my experience in South Asia there is a strong preference of pour-flush over dry toilets. My feeling is that this has something to do with a very strongly held concept that water has a purifying and (ritually) cleansing effect. For this reason the "wet ecosan" or urine diverting twin pit (UDTP) toilet has been developed in Nepal. This is a traditional twin pit(or Sulabh) toilet with a urine diverting squatting pan.

In Nepal this toilet is readily excepted and appears to be more popular then the UDDT, however in communities where insufficient water for even a pour flush is available (year round!) it is much more difficult to sustain operation.

I have not worked in an African context, but would suggest the following thought process to be included in a discussion on which toilets are more suitable:

1.) Is there enough water available for year round operation of a minimal flush toilet option (squatting or pedestal, based on local preference)? This is not purely yes/no but more on a scale of 1 to 5.

2.) How strong is the "cultural" preference for a water based solution?

After asking these 2 questions I think the community and the project can come to a conclusion about what is best by balancing the wish for flushing (which often exists) against the possible added burden of having to get more water for the household.

Off course other factors, like soil condition, also play a role and should also be discussed.

In short, deciding on which toilet has the best chance of sustained use is likely to be influenced by very local factors and therefore we should start with an open mind and help the community decide between the options available.

Kind regards

Marijn Zandee

Moving forward with this discussion, please see link to pour flush toilet video from Partners in Development:



The toilet was modified to have low flushing cistern and was piloted in South African schools. The lessons learnt are available on Susana to download:

www.susana.org/lang-en/library/library?v...eitem&type=2&id=2000

New video from Partners in Development:



Through partnership with the Dept of Science & Technology, over 250 units have been installed in Eastern Cape Province, South Africa.

Hi Sudhir
Thanks for this new video about the developing popularity of pour flush systems in SA. If the leach pits are kept free from solid waste it would be useful to know what the rate of sludge build up is and whether they ever need to be emptied. A concern is the content of the leachate and the size and depth of the leaching zone. The latter will depend on the soil characteristics and rainfall plus ground water depth. How much microbiological degradation can take place in a stagnant leach pit? Can we use some of the experience with septic tank technology and dewats systems to improve the design of the leach pit in order to improve leachate quality?

I have seen leach pits in urban areas designed to never be emptied and rightly so the pits never fill up. One might ask are these systems sustainable in high density urban areas where leachate volumes per unit area would be considerable? For rural I think there is a good future as long as ground water wells are kept some distance away.
Regards

Hi Arno

Attached is the sludge characterisation study lesson. This was performed by UKZN. Some of your questions are covered in that lesson series. Although it does not have anaerobic / aerobic degrad. tests per se, there are parameters that can be used to determine the degradation and you find it inside the short doc. Enjoy the read.

Simon Lorentz and co also did the leaching study "Investigation into Pollution from On-Site Dry Sanitation Systems". I have also added that in attachment.

Dave Still has done the Sludge Accumulation Rates (SAR) for the toilets - its obviously much longer than VIP latrines. We have some of this data for homes and schools (institutions).

Hi All,

I've just read through this topic, had a thought, and am now looking for some input. One of the early postings states that 392 liters of waste and flush water accumulate (worst case) in the storage tank of a closed, pour-flush toilet. I've been working on a manual pump that can pump 400 liters of sludge in less than 6 minutes (depending on shear strength and debris loading). Is the following concept feasible: Pour-flush toilet feeding a 400 liter, sealed tank that needs to be emptied annually. If the tank is properly designed, the pump could be attached, tank emptied, and pump detached, in 10 minutes. The real effort would be getting the extracted waste to an appropriate dump/treatment site. From an economic perspective, is there a realistic business model here?

Cheers,

AW

Hi Andrew

We observed a median of about 23 litres of sludge accumulation per user per year with the pour flush toilets we were monitoring. Interestingly that is the same number (give or take) that Kitty Foxon came up with for VIPs once you take out the trash fraction.

But the leach pits were not sealed. If they were sealed then the accumulation rate would be several litres per user per day, so the 400 litres would not last long at all for a normal sized household.

Regards

Dave