Hi everyone,

I would like to invite you to see a 4-minute video that a friend and I just did concerning the management of feces from UDDTs in woven, polypropylene sacks. All of the info is in Spanish and English subtitles, so you can either turn the lively Australian didgeridoo sound track up or down according to your preference.



We did this video to show that the option of storing feces in these sacks is very simple, practical and scalable (and not so terrible as people may imagine), plus to demonstrate the feasibility of reusing the cover material after a prudent detention time, especially in the context of the recent discussion of GIZ's new Technology Review of UDDTs. The video also shows the rain-filled TippyTaps we make from rescued plastic bottles.

I would also like to take this moment to announce a 2-part interview with me about the problems with water-based sanitation and the benefits of UDDTs:
www.chekhovskalashnikov.com/water-sanitation/
www.chekhovskalashnikov.com/human-waste-disposal/

This includes links to numerous relevant webpages and videos, while avoiding technical jargon, thus we hope it will be useful for EcoSan consciousness-raising.

As always, please let me know if there are things to be corrected or polished in this video or in this interview.

Best wishes,
Chris Canaday

very nice video, Chris!

I like how clean and simple you show the emptying to be- so much different than what many people imagine.

Liz

Great video Chris and nice interviews as well

I am inspired by the work you do - heading for Cambodia soon and intend to see what communities know of, and think about, UDDT's.

And if hearts and minds can be won away from flush and sewer systems to the new cool UDDT (it's aspirational marketing that will win out at the end of the day:)

Dear Dennis,

Thanks for the encouragement. Please let us know how things go in Cambodia ... and if we can be of any help. Dry toilets are the toilets of the future, if people want to be civilized with their neighbors, with future generations, and with nature. It is also key if we want to eat in the future, as it allows us to safely recycle nutrients back to our crop plants, especially after the non-renewable chemical fertilizers have run out. Please tell us more about you and your organization.

Best wishes,
Chris Canaday

Hi Chris

any comments / experience on the use of your uddt system in high water table / flood prone locations?

your bin arrangement seems like would be high enough to accommodate reasonable water incursion and the stored bags too - and if major flooding, well god and allah's will be done:)

cambodia particularly around mekong river and tonle sap lake is high water table and flood prone so am bound to get these questions

thoughts or mods to suit?

my background

very briefly, i am a marketer / entrepreneur looking for problems to solve (ex Australia). have been living in malaysia now for 6 years

seems like asia developing countries can fit that need of mine:)

development experience limited but now contracted to develop mobile vocational training in cambodia from january for about 4 years

believe there is a need for developed country project managers and funders to pass on development capacity skills and knowledge to locals - and then get out of the way:)

currently building out a training programme "The JigSaw Puzzle Workshop" and related business programmes to do just that

if interested, email me at This email address is being protected from spambots. You need JavaScript enabled to view it. and i will send flier, could be useful for south america and africa as well

Hi Chris (and any other readers, particularly Christoph who has been active in UDDT's for some time)

Questions on UDDT Systems

Have been working through the sanitation issues and challenges in my mind and have some questions which I hope others can help me with, (as I think about incorporating an overview of sanitation and UDDT's into training with with low resource, remote and rural communities soon) - and rather than belabour everybody over multiple posts, I thought I would simply lay them all out here.

Please feel free to comment as you see fit

Chris Canady, some relate directly to UDDT's and your system (as I have seen it from the blog and videos); others are of a more general nature

I have broken the entire sanitation system into components so I don't forget any parts (I hope:) - please view this as if you were tutoring a slow learner:)

Generally, my enquiries from this post are

a) did I get the system correct - nothing missed out, nothing I have misunderstood?

and b) answers to the specific questions in the components below

• 
  Toilet style - squat vs sit

Q1. I personally am agreed on squat rather than sit for health reasons - is there any discussion needed on this point?

Q2. For those who need physical support while squatting (older / ill / disabled people), particularly when cleaning afterwards, what have people seen used that is effective - or do we need to design some for low resource communities?

Are there useful designs (handles, grips, rails etc) for squatting support - during, at cleaning and getting up after?

(Even I, as relatively young - well 48 - and fit guy, can find squatting a challenge - but that's probably lack of practice:)

• 
  Anal Cleaning Options

Q3a. What is used in low resource communities now where anal washing is the norm - and how is the water supplied (simple bucket, tank with hose)?

I have seen and used spray hose (when you have piped water), small bucket (both from tap and from bucket or reservoir in toilet area) and bidet style (inbuilt into both squat and seated toilet)

Q3b. What impact does anal washing (due to the extra water in the faeces) have on the sludge in a UDDT scenario (ie the drying time, the smell, the attraction to flies etc) - is it minimal or is it significant?

Q3c. And if significant, do you need to add an anal wash diversion into the system? (which seems like a complexity I wouldn't want to get into)

Q4a. For wiping cleaning - what wiping materials are being used in low resource settings (newspaper, other paper, toilet paper, leaves, etc?)

Q4b. What impacts do the various wiping materials have on the sludge breakdown / processing?

Q4c. What wiping material have people found is most suitable for the purpose that is usually readily available in rural settings, is biodegradable and won't detract from the sludge processing / breakdown and is also non-damaging / painful to the user (based on personal experience, after a case of extended diarrhea from street food, using rough wiping paper is NOT recommended if you need to mind the house and kids (wife), go to the paddy field and work all day (husband) or concentrate in school (kids) - or just get through your day

• 
  Faecal cover materials

Q5a. For faecal cover materials - what cover materials are being used in low resource settings (leaves, soil, saw dust, etc?)

Q5b. What impacts do the various cover materials have on the sludge breakdown / processing?

Q5c. What cover material have people found is most suitable for the purpose that is readily available, is biodegradable and won't detract from the sludge processing / breakdown?

• 
  Impact of Urine in Faecal sludge

This component goes to the core of UDDT's - while I am a believer in onsite faecal drying and processing, to prevent the high cost and maintenance of sewered and septic tank systems and to retain the nutrients locally for agri use, I feel I need to ask the following questions:

Q6a. How detrimental to the overall process of drying the faeces is the urine really? is it make or break whether the urine is diverted or not?

Q6b. Or is it just that, if urine is not diverted or the anal washing water volumes are high, the faecal sludge drying process needs to be enhanced (via more cover material and / or improved solar or air drying systems) so that the faeces and urine mix is dried out quicker to prevent fly infestation and odour?

• 
  System Design

Chris, I see that you mentioned running a perforated urine pipe from the toilet to an area outside, so people didn't need to empty the urine bottle;

Q7a. Does the urine pipe need cleaning and if so, how often and with what? (Stale urine is a fairly bad smell to have around - not quite as bad as uncovered faeces but still ... so I guess you need to wash the hose / bottle occasionally)

Q7b. Does the addition of the urine pipe add to the complexity of the either design and / or installation to the point where it could be a turn off to users (or potential users)?

I assume you need to make sure you have enough pipe drop from the toilet to the dispersal point (with no flat / level parts) so you don't get pooling in the pipe anywhere

Q7c. Does the pipe get blocked at all at the perforations? (which could mean stale urine sitting in the pipe) - irrigation pipes do, so I guess this would too

Q8. Any comments / experience on the use of uddt system in high water table / flood prone locations?

Chris, your bin arrangement seems like would be high enough to accommodate reasonable water incursion and the stored bags too - and if major flooding, well god and allah's will be done:)

Cambodia (where I am heading but this relates to may countries) particularly around mekong river and tonle sap lake is high water table and flood prone so am bound to get these questions

• 
  Toilet Structures

Many of the sanitation projects I have read about failed because people paid for the toilet, but then had to wait for the structure to be installed (or wait until they could afford the structure, which often cost more than the toilet)

Q9. What low cost toilet structures have people seen that could be easily built by low resource communities?

I believe there needs to be more than just a wrap around cloth structure (people don't see that as sufficient I believe) but a design that is very low cost must be available - or could be designed

• 
  Collection and disposal

From Chris's video, the collection and disposal process for your system (all on site and managed by the household ) is workable but

Q10. can anybody advise whether, in either a community or peri-urban setting, they have seen the processing be centralised at a community level, so that for example, larger solar driers could be built and the community (either separately or via a collection service) could centralise the processing at one point?

I think that is it

Hope those with experience including Chris and Christoph (and even my new post colleague Kevin:0 can help me here

Hi Dennis,

Wow, that's a lot of questions (made me realise that more details are still needed for the Wikipedia page on UDDTs ).

Just three quick answers or links to make you aware of previous discussions here on the forum (so that we don't re-discuss this from scratch):

Discussion on squatting versus sitting, please see here:
forum.susana.org/forum/categories/141-ot...squatting-vs-sitting

Discussion on UDDTs for people who use water for washing, please see here:
forum.susana.org/forum/categories/141-ot...nique-situation#6668

or here the discussion on UDDTs for Muslim users:
forum.susana.org/forum/categories/34-uri...-in-muslim-countries

As for the covering materials - as the UDDT Technology Review and the Wikipedia article state - you can use basically anything that's dry and that is available. It doesn't even need to be biodegradable, e.g. you could also use sand (or lime). Just anything that doesn't harm the soil later if the dried faeces are buried or applied to the soil. I think people just use whatever is easily available.

Chris Canaday has written in several places on the forum about the use of compost as a cover material and Christoph Platzer has written several times on the forum that he is not in favour of that (due to safety aspects). I tried to find Christoph's post about it with the search function but couldn't locate it yet. But one of Chris Canaday's posts about it from 3 years ago is here: forum.susana.org/forum/categories/34-uri...terial-in-uddts#2866

Hope this helps a little bit even though it is only a partial answer to your long list of questions. I am sure other people will also chip in to help answer them.
And afterwards, I am going to improve the Wikipedia page about UDDTs to "capture" these questions and answers.

Regards,
Elisabeth

Hi Dennis and everyone,

Sorry for the delay. I have been a bit tied up.

It is a pleasure to help answer your Questions on UDDT Systems.

Q1. I personally am agreed on squat rather than sit for health reasons - is there
any discussion needed on this point?

Squatting is certainly the best position, in terms of health and hygiene. It is
also simpler and less expensive to build, plus we get better separation of the
urine. See
http://www.toilet-related-ailments.com%2Fbenefits-of-squatting.html
----This is very much a cultural matter. People who have grown up with sit-down
toilets will want to sit ... until they want to improve their colon health, have
better hygiene, and build their UDDTs less expensively.
----Convincing westernized people to even think about toilets for squatting in the
Western Hemisphere is an up-hill battle, since they have never previously seen a
presentable toilet for squatting, only funky, fly-filled latrines. People aspire to
having sit-down toilets, since that is what they see in fancy homes.

Q2. For those who need physical support while squatting (older / ill / disabled
people), particularly when cleaning afterwards, what have people seen and used that
is effective - or do we need to design some for low resource communities?

I have not done one yet, but I think it would be feasible to make a lightweight,
portable seat that can be placed on the squat toilet to allow people to sit. when
not needed, it can be placed out of the way.

Q2a. Are there useful designs (handles, grips, rails etc) for squatting support -
during, at cleaning and getting up after?

Yes, it is very good to put a handle for holding on to, especially if some of the
users are Westerners who are not accustomed to squatting. Sometimes, I cut the
handle from a plastic jug and nail or screw it onto the wall to hold on to. (The
rest of the 20- or 40-liter jug can hold the sack, see
inodoroseco.blogspot.com/2012/04/aumentamos-un-tacho.html )

Q3a. What is used in low resource communities now where anal washing is the norm -
and how is the water supplied (simple bucket, tank with hose)?

Everyone seems to be wipers here, but from what I understand washers tend to use a
bucket. This seems very unhygienic, and I would like to develop something along the
lines of a TippyTap ( www.tippytap.org ) for this washing.

Q3b. What impact does anal washing (due to the extra water in the faeces) have on
the sludge in a UDDT scenario (i.e., the drying time, the smell, the attraction to
flies etc) - is it minimal or is it significant?

Anal wash water should be kept separate, maybe via a separate basin/funnel behind
the fecal drop hole (as some squat pans are made in India). This water should go to
soak pit or some sort of artificial wetland, for treatment. The amount of smell and
flies generated by mixing water into the feces would be variable, depending on
climate, cover material, intestinal health of the users, etc.

Q3c. And if significant, do you need to add an anal wash diversion into the system?
(which seems like a complexity I wouldn't want to get into)

As I said, yes. And it does not seem so complex. It would be more of a problem if
the unit produces smell and flies.

Q4a. For wiping cleaning - what wiping materials are being used in low resource
settings (newspaper, other paper, toilet paper, leaves, etc?)

Yes, all of the above. Here in the Amazon there are excellent, soft, perfumed
leaves. Some indigenous people use corn cobs or carefully prepared sticks.

Q4b. What impacts do the various wiping materials have on the sludge breakdown / processing?

No problem, as it all breaks down (even though the mentioned sticks take longer).
We almost never see toilet paper the next year, although this may show up more in drier climates.

Q4c. What wiping material have people found is most suitable for the purpose that is usually readily available in rural settings, is biodegradable and won't detract from the sludge processing / breakdown and is also non-damaging / painful to the user.

Carefully selected leaves, like Piper auritum
( en.wikipedia.org/wiki/Piper_auritum ), are great, as are other selected Piperaceae and Melastomataceae.

(to be continued ...)

Best wishes,
Chris

fascinating, Chris - what a wealth of useful practical detail!

Squatting is good unless, in my experience, you are wearing tight-fitting pants (I mean underwear, but trousers might have the same effect). Thus shackled, or hobbled, you can end up tipping over and/or trailing underwear unhygienically on the floor.

I am interested in the implications because the majority of menstrual hygiene management practices advocated at present require tight-fitting pants. I wonder what the women you work with find to be their experience? Do they have strategies for managing tight-fitting pants? Or do they avoid them, with the attendant implications for menstrual management?

Thanks, Susannah

(here is the second part)

Faecal cover materials

Q5a. For faecal cover materials - what cover materials are being used in low resource settings (leaves, soil, saw dust, etc.?)

Wood ash works well, but many times there is not enough, even in communities where all the cooking is done on wood fires. Leaves are good, but intact they are too coarse to cover the feces properly to keep flies from getting in and smells from getting out. Sawdust works and can smell nice, depending on the species. Rice hulls are great, where rice is grown. Soil is excellent, abundant and nearly universally available. (Richer people sometimes buy mineral lime, but this causes unnecessary environmental impact in its mining, processing and transporting, plus, in my opinion, it is overkill, being stronger than needed.)

Q5b. What impacts do the various cover materials have on the sludge breakdown / processing?

This is key and many people do not give it much thought and just use that which is easiest or prettiest. I suggest that we should not want to just cover the feces, but also inoculate them with beneficial decomposer soil microbes and assure that enough air can flow through the pile. For this latter function, we can add bulky or fibrous materials that decompose slowly, like rice hulls and egg shells.

Q5c. What cover material have people found is most suitable for the purpose that is readily available, is biodegradable and won't detract from the sludge processing / breakdown?

As Elisabeth mentioned, I recommend recycling cover material, in other words, covering new feces with that which is left of decomposed old feces (and mostly the cover material from the previous cycle). Obviously, this is a radical idea that many are not able accept (like our friend Christoph), but this just a theoretical prejudice, since in practice there is nothing disgusting or dangerous about it, as long as treatment has been done properly. This is a matter of trusting our treatment via long storage, heat, solarization, themophilic composting, etc. and realizing that pathogens die off over time and that normal soil microbes predominate over time. Some would say that we cannot trust people to do the treatment right, but any system can be used wrong (including centralized sewage systems that suffer numerous sanitary accidents).
---- Food comes from the soil, so if we give it the right conditions and enough time, why can’t it become soil again? If treated ex-feces are always still considered feces, this means that we are gradually converting the entire planet into feces, which I do not believe is the case.
---- One of the most surprising aspects of this recycling is that we have roughly the same volume of material year after year. Feces are mostly water that evaporates and bacteria that finish eating each other, so with time and decomposition they take up very little space. One time we used straight rice hulls as cover material and when digging it out the next year, it was nearly the same unchanged rice hulls, with little difference noticeable.
---- This recycling allows us to provide new users with all the cover material they will ever need (until the family grows). This is especially important in the middle of the city, in the middle of the forest, or on an island in the middle of the ocean, where there is not easy and constant access to new cover material.
---- If we are worried about pathogens still lingering in the ex-feces, which should be minimal or non-existent if our processing is adequate, the worst thing would be to spread them in the open environment, where anyone could have contact and the wind and the rain could carry them to others. When scooping this recycled cover material, users have some contact with them, but their hands were already dirty from anal cleansing, and this contact can help remind them to wash their hands, which we wanted them to do anyway. An optimal system might add cover material mechanically, without the user having any contact, and various such mechanisms exist or are on the drawing board.
---- This recycling would be worthwhile in terms of the microbiology, even if it is in such a small percentage that it is not visible … but why not just recycle it all of it and not have to get and transport so much new cover material all the time. I sift all the cover material through a 1x1 cm steel mesh to make it uniform and presentable, and sometimes I find 5-cent coins, which I suspect children dare each other to swallow.
---- To get started, I would recommend mixing 50% rice hulls with 50% dried human or animal feces, compost and/or rich soil. Maybe include some biochar, too.
---- I have mentioned this a number of times on this forum and here are three of the posts:
forum.susana.org/forum/categories/34-uri...mit=12&start=12#9499

forum.susana.org/forum/categories/17-fer...rt-of-processing#505
forum.susana.org/forum/categories/17-fer...imit=12&start=12#531

Impact of Urine in Faecal sludge

This component goes to the core of UDDT's - while I am a believer in on-site faecal drying and processing, to prevent the high cost and maintenance of sewered and septic tank systems and to retain the nutrients locally for agri use, I feel I need to ask the following questions:

Q6a. How detrimental to the overall process of drying the faeces is the urine really? Is it make or break whether the urine is diverted or not?

I have not done trials mixing in the urine, but it is logical that keeping the urine separate helps to control smell and efficiently give nitrogen back to the plants that we want to grow. The amount of smell generated with the urine mixed in would vary according to climate, cover material, and number and health of the users.

Q6b. Or is it just that, if urine is not diverted or the anal washing water volumes are high, the faecal sludge drying process needs to be enhanced (via more cover material and / or improved solar or air drying systems) so that the faeces and urine mix is dried out quicker to prevent fly infestation and odour?

We should generally always strive to keep the feces pile as dry as possible, preferably via passive methods.

System Design

Chris, I see that you mentioned running a perforated urine pipe from the toilet to an area outside, so people didn't need to empty the urine bottle;

Q7a. Does the urine pipe need cleaning and if so, how often and with what?

We have not had any trouble with the perforated hoses plugging, if they are done right (no Ts, no joints, plastic mesh in the funnels to keep junk out, etc.). In fact, we have had trouble with the hoses unplugging too much: rainforest mammals biting into the hose to get to the salt and other nutrients present in the urine, if the hose is not buried (usually 10 cm under the surface).

Q7b. Does the addition of the urine pipe add to the complexity of the either design and / or installation to the point where it could be a turn off to users (or potential users)?

It is a bit more work during the installation, but then it is just there working and no one has to deal with it. No fuss, no muss, no smell.

Q7b1. I assume you need to make sure you have enough pipe drop from the toilet to the dispersal point (with no flat / level parts) so you don't get pooling in the pipe anywhere

We do try to keep the hose sloping gently downhill. Sometimes I use a bubble level to assure this. We had such a system on DIY waterless urinals at a local high school for over a month with no smell problems or any other problem (until a mischievous student messed it up and the janitor finished messing it up).

Q7c. Does the pipe get blocked at all at the perforations? (which could mean stale urine sitting in the pipe) - irrigation pipes do, so I guess this would too
We have not had trouble. There are many perforations (usually one every 50 cm) and I presume that if one hole plugs, the urine flows out of another until bacteria, ants or whoever unplugs the plugged holes. Note that this is not drip irrigation (which would plug). I like to make the holes with pieces cut from lollypop sticks, which are tiny pipes with internal holes of about 2 mm. These get inserted into the cheapest half-inch black hose (for electrical connections).

Q8. Any comments / experience on the use of uddt systems in high water table / flood prone locations?

Yes. It is just a matter of keeping the containers for the feces above the floodwaters, although sometimes we make ferrocement walls that keep the floodwaters out. Urine is mostly not infectious and would get filtered through the soil (in the system described above) before joining the floodwaters. See
inodoroseco.blogspot.com/2009/05/inodoro...-zonas-de-altas.html

---- Thanks, Dennis, for your interest in this. Please do not hesitate to send more questions. Also please tell us more about your project.

Best wishes,
Chris Canaday

Hi Susannah,

I am glad you like this info.

What I like to do is unshackle myself by removing my shoes, trousers, and underwear, in the privacy of the UDDT, and squat freely, without straining against the clothing or worrying about some of this clothing getting soiled. It only takes a moment more and we keep the floor clean, so I do not mind touching it with my bare feet. (One could use Japanese-style bathroom slippers or step back into one's shoes.)

I do not know if the women in our ethnobotanical park do the same. I would guess that they gather their trousers and underwear around their knees while squatting. I will try to discretely ask some of them. What I have noticed is that the squatting UDDT gets more use from our regulars (including men and women) than the sitting UDDT next door.
inodoroseco.blogspot.com/2009/03/los-ele...cologicos-secos.html

Best wishes,
Chris Canaday

Hi Everyone,

(Here is the third installment of my responses to Dennis’s questions…)

Toilet Structures

Q9. What low-cost toilet structures have people seen that could be easily built by low resource communities?

People mostly insist on making privacy walls with wooden planks, but these are costly and cause deforestation. Sometimes we build under the arrangement that the family put up their own privacy walls and there is often a great delay while obtaining planks. I would prefer that readily available materials get used, preferably letting more light in, so the toilet is not a dark, dreary place. One option is palm leaves, as they are widely available in the forest or along urban avenues and they allow more air and light in. Bamboo, Elephant Grass, strips of palm wood, corn stalks, or potentially post-consumer plastic could be woven with string to form privacy walls. The gaps are not as much of a problem as one would think, since the person inside can see out much better than the person outside can see in. Nonetheless, a more solid wall may be preferable at schools, where there is a higher density of mischievous kids. Another great option we have applied several times is to simply wrap the structure in a sheet of white plastic, which leaves no gaps for peeping and allows so much light in that it seems that we have electric light during the day. I refer to the common plastic sold from rolls at the hardware store for about $1 per square meter, which lasts for years if no mischief is done to it (and mischief can also destroy concrete block walls).
---- I have another radical idea on this front. I think that millions of people prefer open defecation because the air is fresh and clean and they are standing on a surface that has be washed by the rain and sterilized by the sun (even if they have not thought this through in quite these terms). I propose we experiment with UDDTs that offer the same, by not having roofs and the privacy walls are minimal and could even be hedges of flowering plants or a lattice with vines. The fecal drop hole would have a lid to keep rain out (and potentially would open via a pedal the user steps on while using the toilet and then it closes automatically when the user leaves). The privacy structure could be spiral, such that no door need be made and the user could place a stick between the hedges at the entrance, or something like that, to show that it is occupied. The actual toilet could have steps to gain some height or, if the water table is sufficiently deep, the containers for feces could be underground.
forum.susana.org/forum/categories/71-beh...s-are-available#9692
---- Do you have any photos of the wrap-around cloth structure you mention? Offhand, it does not sound so bad. For example, the thicker grades of shade cloth for flower plantations would give enough privacy and would be resistant to solar UV. This could be a case of gradually investing in individual families based on their proper use of the UDDT: the privacy walls could initially be simple and inexpensive and then be upgraded after they have shown proper use.

Collection and disposal

Q10. Can anybody advise whether, in either a community or peri-urban setting, they have seen the processing be centralised at a community level, so that for example, larger solar driers could be built and the community (either separately or via a collection service) could centralise the processing at one point?

Sanergy, Sanivation, X-Runner, and SOIL (in Haiti) are doing centralized treatment, although not the simple storage of sacks, like I do. I can imagine building a long A-frame with a metallic roof, maybe an equilateral triangle in cross-section and 2 m high, made such that sections can be propped open for sacks to be placed inside or taken out. The temperature should get quite hot inside, especially if the metallic roof is painted black, and the required detention time for pathogen die-off might be one month or even less, and could be determined via searches for Ascaris eggs (and envelopes of plastic mesh holding Ascaris-laden feces could be added, if the users do not have Ascaris). The metal roof would protect the polypropylene sacks from solar UV, thus the same sacks could be used year after year.

Best wishes,
Chris Canaday