SuSanA - Forum Kunena Site Syndication Thu, 23 Oct 2014 17:52:41 +0000 Kunena 1.6 SuSanA - Forum en-gb Re: latrine technology question about the use of two chamber rural latrine septic tanks - by: Emilio
The use of a second chamber or a direct conection to a soak away and the pollution of water table depends on the population density (how many toilets per hectare and how many people use one toilet), available space for infiltration, soil caracteristics and the depth of the water table. There is also in function of the aforementioned conditions a minimum distance from the pit to the water well

By design it is admited than this type of latrines use 2-3 liters water at the most per flush then the water volume to dispose is small compared to a home septic tank where other waste water is recieved. For more details see Wagner and Lannoix Excreta disposal for rural areas and small comunities WHO 1958 (
downloadable from this link]]>
Sanitation systems for special conditions, resiliant risk reduction Thu, 23 Oct 2014 17:19:09 +0000
Re: latrine technology question about the use of two chamber rural latrine septic tanks - by: rhockkh
Thanks for your response - very interesting.

Essentially, I'm wondering if the additional piping (see red pipe in attachment 2) will ensure that 'safer' water will drain into the second soakaway tank than the original piping set up in attachment 1?

Sanitation systems for special conditions, resiliant risk reduction Thu, 23 Oct 2014 01:48:42 +0000
Re: latrine technology question about the use of two chamber rural latrine septic tanks - by: Florian
The baffle separates the tank in two compartments (some design have even 3 compartments), which helps retaining solids, either sludge sinking to the bottom or floating scum. The clarified liquid can be further treated or infiltrated. After a certain period, accumulated solids need to be pumped out, as otherwise volume for accumulation would become too small and solids start to be carried over to the next chamber or the soak pit.

Single chamber systems are less efficient for retaining solids, so more solids start entering earlier in the soak pit, where over time they lead to clogging.

The main difference between a well designed two-chamber septic tank and a single chamber tank is the life time: if the 2-chamber tank is properly maintained (desludged according to design intervalls) its lifetime is basically unlimited. A single chamber system will becomed clogged at some time (how fast depends on soil characteristics) and need to be replaced.

As for the contamination of groundwater, there is no difference between a one or a two chamber system. In a one chamber system, the solids will also be retained, just in the soil matrix around the soak pit rather in the tank itself. In both system, clarified wastewater (containing up to 50 % of the total BOD and still an important load of pathogens) will infiltrate and may contaminate the groundwater. If contamination of groundwater is really a problem depends of densitiy of the septic tanks, of soil properties, and of the type of use of the groundwater.

It's a bit different if the tanks do not drain into a soak pit but into suface water or a drainage ditch. Then pollution from single chamber systems (or badly maintained two-chamber systems) is definitely worse than from well maintained two-chamber septic tanks.

This is all generally speaking. I'm not so sure what exactly is the situation you are dealing with. Your attachment 2 shows the same as 1, also a 2 chamber system, just with some difference in the placement of the pipe connecting the two chamber.

I know that in Cambodia (and elsewhere) single chamber systems, soak pits are common in rural pour flush latrines. These fill up after some time and need to be replaced (often designes foresee two of such pits, to be used alternatively.

Regards, Florian]]>
Sanitation systems for special conditions, resiliant risk reduction Wed, 22 Oct 2014 10:08:32 +0000
latrine technology question about the use of two chamber rural latrine septic tanks - by: rhockkh
I have a latrine technology question about the use of two chamber rural latrine septic tanks (see attachment 1).

It has been suggested to me that it is very important to include a ‘baffle’ (see attachment 2) inside the first sealed tank to drain blackwater from the middle of the tank into the second soakaway tank.

This ‘baffle’ needs to drain water from the middle of the tank. It is very important for the connecting pipe not to drain blackwater from the top of the first tank as this will drain scum floating on and slightly below the water surface. The water that is then drained into the second soakaway tank from the middle of the first tank will be much safer to be then allowed to discharge into the local water table – approximately 70% harmless was quoted to me.

My question is why this ‘baffle’ is not a prominent feature of all septic tank designs used in Cambodia (where I currently work) – as in attachment 1 above where it is present but not to the specifications in attachment 2 (or as detailed in the literature)?

And why are single tank designs promoted in Cambodia that seem to take no account of the potential to contaminate local water tables?

Looking forward to any insight on this.

Best regards

Richard Hocking
Development Professional
Siem Reap
Sanitation systems for special conditions, resiliant risk reduction Wed, 22 Oct 2014 09:33:18 +0000
Re: Sanitation risk assessment - by: muench [Start of Page 2 of the discussion]

Dear Jonathan and team,

I am just wondering if you can already give some feedback on what came out from the questionnaire work that you carried out in May or an update on this research project in Maputo?

I was prompted to ask because of this post about a project by TU Delft which deals with wastewater reuse in Maputo:

Their project is described here:

I will also ask over in the other thread if there is any overlap or common interest with your project. Just wondering as they both deal with wastewater/sanitation in the same city.

Sanitation systems for special conditions, resiliant risk reduction Fri, 10 Oct 2014 07:23:31 +0000
37th WEDC Oxfam Peepoo presentation - by: asaangelino

For more details on Peepoo please contact
Åsa Angelino ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )
Erik Josephsson ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )

* Typhoon Haiyan in the Philippes, see also (note added by moderator EvM)]]>
Sanitation systems for special conditions, resiliant risk reduction Mon, 22 Sep 2014 15:40:35 +0000
Re: 3D printing: what does it mean for sanitation and shelter? - by: Angus
I've written a little bit more about it here:]]>
Sanitation systems for special conditions, resiliant risk reduction Fri, 15 Aug 2014 13:46:38 +0000
Re: 3D printing: what does it mean for sanitation and shelter? - by: JKMakowka
Could be a cool tool to do some piloting closer to the actual users and then have a blueprint for larger scale production. But for the most part, there needs to be less piloting and more scale-up...

But as mentioned in the article, anything that needs a low volume of custom-made parts, like a leg prosthesis, could really benefit from this.]]>
Sanitation systems for special conditions, resiliant risk reduction Thu, 14 Aug 2014 18:03:53 +0000
3D printing: what does it mean for sanitation and shelter? - by: rahulingle
Just came across this interesting article and it is amazing what 3D printing technology can do. It would be interesting to explore its possible applications in the sanitation sector.

"Oxfam is already trialling 3D printing in its Lebanon office as part of efforts to improve sanitation across the country. The charity was donated a 3D printer by the company iMakr, and has used it to build parts of taps and faucets, as well as replacing missing parts of British sanitation kits imported to the region."

"Oxfam is also considering how 3D printing might help it develop emergency shelters. Gilles Retsin, co-founder of Softkill Design, is one of the first designers working on 3D printed housing in the UK. "There is quite a lot of interest in it from people involved in emergency housing and crisis housing. They come from the view that it might be possible to print something very quickly in an unexpected site without the need for shipping anything. We would transport a printer and then we would use the materials on the site, such as sand," he says."

Link to article:


Sanitation systems for special conditions, resiliant risk reduction Thu, 14 Aug 2014 16:00:11 +0000
Survey on product development in emergency sanitation - by: yokepean
I writing to request your support in completing a questionnaire on product development in the emergency sanitation sector. Some of you may have already received this via email.

The purpose of this study is to examine support for product development in the emergency sanitation sector. This is an area which has not been fully researched in the context of emergency sanitation. Specifically, the study is part of a doctoral research project to identify ways to support innovation in the emergency sanitation sector. The thread on my overall research may be found here:

If you have even been involved or intended to become involved in developing new products or technologies for emergency sanitation, either directly or indirectly as a customer / aid agency, supplier, product developer / designer, funder, researcher, consultant, etc., your views on support for product development will be beneficial to the research and we would greatly appreciate your participation in our study.

If you participate in our study we will be pleased to send you the results of the survey. We would also like to seek your assistance in forwarding this questionnaire to relevant persons.

The questionnaire is attached in the thread and may be completed by filling in the document in your word processor or printing it out and filling it by hand:

This is a strictly confidential survey. No individual response or organization will be identified in our research. Only aggregate results will be reported.

If you require further information please do not hesitate to contact me. A good response rate is critical. Therefore, your time and effort will be greatly appreciated.

Thank you very much and I look forward to hearing from you.

Sanitation systems for special conditions, resiliant risk reduction Fri, 01 Aug 2014 06:19:50 +0000
Integrating Climate Resilience in (national) Sanitation and Hygiene Strategy and Plans - looking for resources and experience - by: pjbury
This is one of my first questions to the forum since I joined in 2012.
I'm working on Climate Resilient Development in the WASH sector, more in particular on providing principles based but practical guidance at national strategy and planning level (also there where this level guides decentralized levels).

I'm not sure I have categorized my question in the best possible way, as yes this is about building resilience and risk assessment based vulnerability reduction. I would have expected a category about national sector management including strategy and planning, but it seems that category is not available.


I'd like to get in touch with those of you working in the same field and be pointed to relevant resources, experiences, documentation and conversations.

Look forward to read reactions.

Greetings from near Bologna, Peter J. Bury (former IRC International Water and Sanitation)]]>
Sanitation systems for special conditions, resiliant risk reduction Wed, 16 Jul 2014 19:49:07 +0000
Reports from the Emergency Sanitation Project (Malawi) and invitation to seminar at Stockholm World Water Week on September 4th - by: jspit
Within the framework of S(P)EEDKITS and the ESP project, WASTE, in close cooperation with Unesco-IHE and Technical University Delft worked the past two years on simple concepts for faecal sludge treatment in emergency situations. On a pilot scale in Malawi, we sanitised faecal sludge using lime, urea and lactic acid and all worked well!

In addition we developed a methodology to empty ‘difficult’ pit latrines by a combination of fluidisation, fishing and vacuum emptying.

I kindly invite you to our seminar in Stockholm, so that we can discuss our findings and future plans. Please find the program and invitation below.

In the meantime, have a look at our progress report and a summary of our faecal sludge treatment findings and future work.




Dear friends,

We are excited to invite you to a seminar at this year’s Stockholm World Water Week, where we will discuss the work and future of the Emergency Sanitation Project (ESP). We value the opportunity that Water Week provides us to reach a different audience (as well as add some much needed sanitation and emergency response focus to the proceedings).

More information is available at the Stockholm International Water Institute website:

Members of the ESP consortium will discuss the work carried out to date and the road forward. We want to work with new partners and do more to address the challenge of sanitation in emergencies.

Date and time: September 4th, 2014 14:00 – 17:30
Place: Stockholm World Water Week, Room K24

14:00 Welcome and Opening Remarks

Theme 1 of the session: Progress to date of the Emergency Sanitation Project
14:10 Lime and Yoghurt: WASTE’s efforts to find innovative solutions in emergency sanitation.
14:25 Higher toilets and firmer foundations: Oxfam’s new sanitation products
14:40 The Limits of Worms: Setting the boundaries for sanitation in emergencies
14:55 State of the Toilet Address: Are we ready for the next big one?
15:30 Coffee break

Theme 2 of the session: Expanding the Emergency Sanitation Project
16:00 Brief Remarks and Summary of First Theme
16:05 Panel Discussion – Addressing new challenges and broadening partnership
17:15 Conclusions and wrap up
17:30 Close of Seminar

We hope you can join us for the event. In the meantime, please see attached our most recent project update and learn more about our work at

See you in Stockholm!

William Carter
Senior Officer, Water, Sanitation and Emergency Health Unit (WatSan/EH)

International Federation of Red Cross and Red Crescent Societies
Chemin des Crêts, 17 | 1209 Petit Saconnex | Geneva | Switzerland
Saving lives, changing minds.
Find out more on]]>
Sanitation systems for special conditions, resiliant risk reduction Sun, 13 Jul 2014 12:53:22 +0000
Re: Sharing lessons from human centered design process in a refugee camp - by: AFoote
I work with Hana on this project and I love the discussion it has spurred. These discussions are are how we continue to improve our methods (and sustainability) in sanitation.

I couldn't agree more that sample size is very important particularly when looking at effectiveness of interventions and I too believe WaSH in general can continue to better by making sure data is statistically valid. I think part of this discussion highlights the difference between qualitative and quantitative research. Typically quantitative research's goal is to have empirical generalization to many verse qualitative research is to gain an in-depth understanding.

Our goal of the focus groups was not to empirically generalize sanitation across all of Kakuma (or even measure impact) but rather gain an in-depth understanding of people's experiences to make improvements.

From the social scientist realm, a focus group can be a great tool for this and the advice for sample sizes fall under a different rule of thumb than surveys for confidence levels. You'll also see the same for key-informant interviews. For example you wouldn't expect someone to conduct 300+ key informant interviews to have an in-depth understanding of sanitation for a particular demographic. The reason for this is the concept of redundancy where after a period of time you start to hear the same thing from subjects of a particular category. For example you'll see in a very widely cited paper titled Focus Groups, Morgan notes the concept of saturation, where each following focus group is not providing new information. For refined participant categories and topics, three-four groups per category can be sufficient.

I hope that clarifies some things and happy to continue this discussion as it's an important one. The biggest thing is when looking to gain an in-depth understanding of behaviors and preferences sample sizes differ from quantitative research. I think as we all know quantitative research often lacks this important in-depth understanding and is one reasons we selected a human-centered design approach, as it excels at getting to the root of human experience.

Also, as Hana alludes to this is not our only measurement tool. Since we are doing sanitation as as service it is very important for us to constantly monitor people's us a and satisfaction. We have instituted many small feedback loops to quickly asses and react to strengths and weaknesses. If the system were to scale to other parts of the camp we would continue to use these measurement and feedback loops to asses the service and make real-time changes. I hope that helps in explaining our approach.

I'd love to continue to hear people's thoughts on the advantages and disadvantages of using a qualitative verse a quantitative approach. My previous role was an analyst at a metrics firm for nonprofits so I really enjoy talking about these things.]]>
Sanitation systems for special conditions, resiliant risk reduction Fri, 27 Jun 2014 16:51:09 +0000
Re: CuveWaters: Sanitation & Water Reuse in Namibia - by: CuveWaters
Thank you for your questions.
Concerning your question on direct costs: as stated in our brochure, the figures that you are referring to are preliminary and only represent an estimation. We are currently in a compre-hensive cost-benefit analysis and will share the results when they are ready.

In general we follow a systematic approach. Currently scientific methods are being used to find out what the optimal combination of sanitation and water reuse in formal and informal settlements can look like.
•One element here is the productivity of the reuse water (hygienically safe and with nutrients N+P) which is used for crop production (irrigation site). The revenues of the production should reduce fees and create jobs at the same time.
•The sanitation and reuse project has 3-4 target groups (end user)
o Shack Dwellers (Shack Dweller Federation initiative)
o Two current informal settlements with a.) dwellers of cluster units as shown in the film (very heterogeneous building structure) and b.) dwellers of a maximum two year old tin shack settlement, which has also established to an expected development site (communal washhouse).
o Temporary visitors (open market etc.) of the washhouses.
•We see the implemented infrastructure as a modular and variable service, which allows improvements in the dynamic urbanization process. This way the informal settlements are set up to become formal houses – already now there are regulations on how many buildings can be registered per plot and even other gradual services (electricity, waste etc.) are being established partially. Even if there are big changes above-ground, the underground infrastructure remains (adaptivity, changing environmental conditions).
•From principle cost-benefit considerations the washhouse seems to be a cost-effective and affordable version for temporary visitors and dwellers of informal settlements, compared to the cluster solution. The demand we could observe at the washhouse currently confirms the affordability.
•Otherwise it basically seems inconvenient to divide upcoming fees by spatially segregated target groups. It is much more common, as it is in Europe, to aim at tariff uniformity in an area and to tariff single facilities like toilets, showers etc. in freshwater-use-units. This would have the effect, that those that are better equipped in sanitary terms can help support those that are not provided with (subsidise).

Best regards,
Sanitation systems for special conditions, resiliant risk reduction Fri, 27 Jun 2014 08:02:45 +0000
Re: Sharing lessons from human centered design process in a refugee camp - by: bracken all the best,
Sanitation systems for special conditions, resiliant risk reduction Wed, 18 Jun 2014 15:20:37 +0000