Hi Stew,

We have instructed some communities here in the Amazon to use wood ash, but the consensus later was that they had to be very careful to collect all of the ash or there was not enough for the UDDTs. And it is key for the cover material to never be lacking, which is all the more reason to use abundant materials and to recycle.

Ash could potentially be part of the mix, but my thinking is that we do not want to try to kill everything with pH, but rather allow the beneficial soil microbes, fighting on their home turf, to wipe out the pathogenic fecal microbes.

Limestone may be very abundant, but its transformation into powdered lime is very labor- or capital-intensive.

There must be some forest there somewhere. I would go out into the forest with a 1x1 cm mesh to separate out the leaves, sticks and roots. The same mesh can be used to sift the dried and decomposed barnyard manure. Even if you do not manage to get very much, a little bit of the right microbes goes a long way. (Please share these messages with the DNAE people; it would great to get their perspective.)

Rice hulls are great and should be very abundant there, so I would put 50% rice hulls.

Wood ash might best be mixed into the urine to improve its fertilizer value, as has been shown in several recent studies.

For the study, you might have 2-3 types of cover material, one being the mix I suggest, another being wood ash.

I suggest only filling the sacks to about 20 liters, so that they do not get too heavy. So changing the sacks can be part of a weekly routine, even if less feces have been collected.

(Thanks for pointing out that you were referring to my video. It seemed you were mentioning another.)

Best wishes,
Chris Canaday

Chris and JKM,

Sure, I'll take all the variables you can throw at this project ... as long as they come with your experience in how to work with them.**

I already omitted sawdust (not that plentiful), and will add D&D manure and soil. Really feel we must try firepit ash or powdered lime to raise pH; lots of 3 rock fires and limestone in Sumba. Your advice is noted.

Cheers,
Stew

** A couple years ago I participated in a joint Rotary Wasrag-UNC exercise to try and provide over 100 variables in various categories, in an effort to semi-automatically identify issues, weight them, and improve the quality of design in WaSH systems. The automation proved fruitless, though the categories did function as a checklist; and surveyors helped us a lot due to that preparation. There's no substitute for local knowledge of culture and conditions, experience in the field, and the wisdom to apply things judiciously. That's why I'm here, learning.

Hi Stew,

Great discussion. Please do not worry about it going new directions.

About the cover material, I would suggest trying to include some kind of soil and/or dried and decomposed barnyard manure. Our climatic conditions here in the Amazon are comparable to those of Indonesia and when we used a mix of wood ashes and sawdust, we had a lot more problems with smell and flies than we do now with the use of recycled cover material. This could even be a new variable for your study (in case you are ready to handle more variables).

Best wishes,
Chris Canaday

This is indeed getting a bit off topic, but for what its worth: yes lots of unknowable variables, but usually you can deal with those through a large margin of error and a multi-barrier approach.

The problem is that in such a resource poor setting this will seem wasteful sooner or later even to well trained caretakers (or more likely to the next guy who takes over after the well trained one gets fed up)... corners will be cut and "annoying" steps conveniently forgotten.

So yeah, complex problem

You are asking me for something that doesn't exist, Stew - namely definitive information about something that varies in multi-dimensional space. I'm not sure anyone is going to be able to give you that level of information.

And anyway, my main point was that the informed villager person is going to have to contend with varying conditions on their own. Whilst you might be able to capture some of the variation with your research project, I'm not sure that you could ever control all of the variables in a village setting w/o any kind of measurement equipment.

Important Note: I think this thread has gotten away from its original purpose to some extent ... to discuss best methods for measurement and tracking temp, pH and moisture, so that a simple process can be verified then repeated.

However, I appreciate all that I'm learning in the dialogue.
Thanks to all participants. (What about the 100 or so that are just viewing ... do you have an opinion on the original questions?)

Stew

Hi Joe,

It is helpful ... but it would be good if we could noodle a little more focused set of parameters. I could provide elevation, ambient temps, rainfall by month, sizes and construction of all containers, info about foodstuffs and diet, water intake, if that would help. The location is close to the equator, so 12 hrs sunlight. There are two monsoon seasons, one with longer and heavier rain.

I don't expect we'll get to a precise formula, but with the experience base here in Susana, could that data and a discussion narrow the design options and help focus our efforts?

Stew

Correctomundo, Dennis.

Yes Stew, important not to confuse the "system" testing and evaluation process with the ongoing usage.

As I understand it, what your testing will do is allow either verification that the management process is effective in achieving the objectives of safe waste management; if not, then you can finetune the system until it is safe, correct?

Once established, the then-defined SOP can be followed by the community with reasonable assurance that the process is safe. And that verification can also be used by other communities (with similar environmental circumstances I guess), based on that data

Different environments will require some individual testing but again, the learnings from the testing regime (equipment, measuring process, data collection etc) can also be used by others too in other locations.

Would that be about right Stew?

canaday wrote: Hi Stew,

Please post the link to the video you mention on triangular solar ovens.

It's at the top of your your thread

I believe the solar dryer box will be rainproof, inexpensive, at least as practical. At present I prefer emptying bins and stirring regularly - it ought to breakup of lumps, dehydration, and makes it more uniform, all faster. We may try the sacks-in-the-box approach, also or later. To many options now will confuse things.

I think you'd find the cover material acceptable - mix of dried minced vegetable matter, husks/hulls, healthy dose of firepit ash, etc. There is presently no dried decomposed manure, the soil is primarily limestone so no rich soil, nor previous UDDTs.

What detention time are you looking at in the ovens?

That's the whole point of my OP - we will be measuring the appropriate amount of time, not starting with an assumption. My goal is to move under 2 months in the collector-dryers; shorter is better.

I think the mentioned expert was talking more from conventionalism than logic. Pathogenic bacteria are much happier in the water and wet surfaces of a flush toilet than in a pile of dry material (esp if there are a lot of soil microbes there) or the the urine funnel getting rinsed frequently with pure urine. Flush toilets can also get plugged and overflow, plus when flushed they send contaminated water droplets all over.
www.chekhovskalashnikov.com/water-sanitation/

Yes, the epidemiologist understands at least some of that.

Those dry toilets were most likely abandoned because the users never fully understood their benefits and proper use. Who knows? They may have also had design flaws, but most likely it was the lack of socialization and follow-up.

They were compost toilets. Yes ... I've asked for background info, studies; so far none provided, so we have no clue.

When do you go to Indonesia and how long will you stay there? Any chance of setting up some long-term volunteers to help with follow-up, education, etc.? (They could also help with other aspects of community development.)

Leave in 10 days. There is a ToT program, volunteer trainers paid stipends, who do CLTS and handwash training. We will train them on the UDDTs, now that they are being installed and getting ready.

Thanks for your kind wishes, and gratefully received advice!
Stew

As I expect you will find, the devil is in the detail. Laid out like this it sounds quite simple, but the reality is that the pathogen dieoff will be determined by many factors which will have to be managed by your 'responsible villager' in the absence of any real training or equipment.

I expect the pathogen destruction to vary enormously, depending on moisture levels, the kind of handling, the ambient temperatures, the level of mixing and so on. Fundamentally you'd have to decide what an 'acceptable' level of pathogens would be and how likely it is that your responsible villager would continue doing things in the optimal way.

Is that specific enough?

Hi Joe,

Please don't be confused by the interim measurements that verify a simpler end process. The end process involves a single vault with baskets, emptied by a family member in a few months, then reused. A central storage-dryer operated by a responsible villager until time and temp have turned it into dry crumbled humus; then mixed into topsoil in gardens. And of course spreading urine, cleaning surfaces and handwashing.

Please be specific ... what do you think is too complicated about it? Or cannot be scaled up? All the literature suggests this is quite within the realm of normal UDDT projects.

Thanks for the link on health measurement ... do you have others?

Stew