We are not only on the same page, we probably co-authored the book!

I totally agree with you concerning forgetting about the fertilizer aspects. If 85 - 99% of all organic materials, including human excrement, urine and food scraps is H2O, the remaining %, if composted correctly, is so insignificant that it could be buried or burned for economically total stupidity safety.

My procedure for the recycle of the compost tea and the composted finished soil is the following.

The excess compost tea is float switch controlled and pumped into a polyethylene holding tank of any size to match the occupancy. It is stored for at least 30 days before I would recommend that it only be utilized for non-edible animal crops or landscapes removed from the site and applied by certified maintenance/service professionals.

The finished compost from our tanks is primarily wet redworm castings and broken down pine bedding, our carbon source. It is always wet because of the flush water and urine from the toilets. Therefore, ANY compost that is removed from any correctly operating composting mass will contain fecal coliform because of the transport of the liquid through the fresh material on top to the bottom, which is constant.

My recommendation is that any compost, tea and/or solid, which is removed from a functioning human composting system be re-introduced into another similar mobile composting tank to be further composted for at least 30 days to eliminate the continuous injection of fecal in the first and primary tank. This mobile composting tank would be just the same as the septic pumper pumping the compost into another composting tank on his truck to be composted further until safe.

Nor am I an engineer! My knowledge has been strictly hands-on trial and error. I approached the wastewater industry with no preconceptions and after reading about the Clivus Multrum composting toilet invention from Sweden I jumped into it up to my elbows.

This is the first Forum I found regarding sanitation and water and I agree that maybe I need to ask you for additional suggestions of Forums that my and your comments may be more appreciated.

Thanks for your extremely valid comments.

Clint

Clint, we are on the same page on this. I've largely withdrawn from this forum because I do not believe in ecosan, unmanaged dispersed systems, etc. My background is not as an engineer and I have almost zero knowledge about the physical structures which commonly form the bulk of the conversation in sanitation discussions. My background is in the soil science and the microbiology of faecal composting - which few seem to want to discuss.

We have good science from meso-scale (which I think is basically village sized) composting systems in Europe and the USA where the pathogen kills were measured in detail over an extended period. Latterly we also have a growing number of studies from developing countries such as from SOIL in Haiti and in South Africa. We therefore know what works and what doesn't work.

We also have pretty good and convincing evidence of systems that don't work. These are almost always small, self-managed, self-organised systems - usually constructed by someone else and run on a day-to-day basis by people with no real substantive education in anything relevant. I think that evidence matches what you've said above: they don't work. They don't produce material that can honestly be described as compost and they don't kill human pathogens effectively.

My position is still the same, and has not changed since I've been a part of this forum: if we cannot tell if the material from a sanitation system is safe, we can only assume that it is not safe. And safety needs to be assessed by a combination of proof-of-concept studies and batch testing of relevant pathogens or indicators.

If we'd expect that kind of work to be done on cheese, why wouldn't we also expect it on human faeces?

Before we even start spreading faeces around and claiming that we're "completing the circle", we need that kind of information and we also need to develop agreed standards for the faecal pathogens. Those standards need to be based on the best risk assessments, which I believe means Microbiological Risk Assessment and Monte Carlo simulations.

Ultimately if we can't do that, we've no business telling people who do not benefit from having access to good laboratories, education, healthcare etc to handle the faeces.

We'd be much better off, if reliable meso-scale composting is not possible, focussing on the sanitation rather than the imagined agricultural benefits of the material. Which, I think, means some kind of ignition, pasteurisation, charcoaling, etc.

Largely we seem to be skirting around the truth: most of the offered solutions do not work in real-world situations. We know what does work, but think of a million-and-one reasons not to apply that knowledge and instead resort to phooey and wishful thinking.

Thank you Joe for so perfectly clarifying the differences between the functionality of the toilet, real composting and the fact that sanitation needs professional/highly-trained/well-compensated (from the profits of the sale of composted liquid and soil amendments from the managed community toilet/shower/laundry facilities) management other than the homeowner.

After spending over 45 years attempting to educate and train very intelligent homeowners on how to operate and maintain the composting and greywater systems we had sold to them and installed in their homes, 100% of those homeowners failed to begin to maintain their own systems adequately and in some cases actually made their own adjustments without any consultation, which resulted in malfunctions and had to be rectified by a trained service person.

To the same extent that we trust doctors and other professionals is that they have invested their energies in education and dedication in perfecting the trade they have chosen to be involved.

Also, as Joe points out, their is a considerable amount of information to comprehend when it comes to separation and recycling technologies, plumbing differences, composting, aerobic treatment, filtration, disinfection, safety, monitoring, etc.

That is why, if people chose to live in close proximity, for whatever reason, either monitored, managed and serviced individual and/or community decentralized separation, treatment and recycling systems, are the most cost-effective, efficient and environmentally and socially constructive methodology available.

Clint

I agree with Clint that it is very common for "composting toilets" to be under-estimating the amount of carbon and oxygen needed for proper composting and pathogen breakdown.

I also agree that an over-focus on the delivery method (ie the toilet) rather than education relating to the whole of the sanitation process is a common flaw, not helped by the persistence of popular "composting toilet" manuals which perpetuate the myth that faecal composting is effective in small spaces and with handfuls of sawdust.

But, I suppose that the "Reinvent the toilet" would have gotten rather less coverage if the offered solutions were to teach people the necessary soil science, microbiology etc they'd need to understand what was happening in the systems rather than supplying large numbers of new types of unit which supposedly fix the problem. As we've seen in agriculture, the trend has been away from types of long-term investments in education and Agricultural Extension and towards more general, oversimplified, non location-specific fixes.

Sadly, I've concluded that many of the systems that are advocated by many in the sanitation space could actually make the problems worse (such as by encouraging users to manage their own faeces they've collected, which in many situations is unlikely to be properly sanitised and therefore may be simply spreading infection). In one sense, at least faeces collected in properly sealed latrines or vaults is being kept away from people. Once we're into the business of emptying and spreading the material onto farmers fields, the risk is much greater than the potential benefits - where there has not been effective composting - in my opinion.

Actually, the FIRST flushing toilet patent was for an earth flushing toilet instead of water flushing toilet.

Why the change from earth, which would have been beneficial, to water, I assume was based upon the knowledge levels at that time to "get it out of here BECAUSE IT IS BAD"! Based upon that technological base of knowledge AT THAT TIME, they used and we continue to use copious amounts of water to quell the odor immediately and then use more water to remove the materials faster to let someone else deal with them because they are BAD!

In my line of work, it is what happens after the toilet that is important. The only NATURAL process I have ever come across is composting. In addition to aerobic composting, we utilize vermiculture, because, as Aristotle claimed worms are , "the intestines of the universe". Red worms further enhance Mother Nature's potential in a decentralized, containerized, automated, protected, secure environment for total transformation and conversion into agricultural soil amendments with minimal amounts of energy and water consumed while protecting and then being able to convert and provide a valuable economic resource and product for agricultural enhancement.

Biologically, Mother Nature and the Creator set up a system of recycling naturally, i.e. composting! ONSITE/LOCALLY/DECENTRALIZED composting systems, utilized in the transformation of a used (not waste) source(s) of material (human excrement AND food scraps) into biologically SAFE liquid and soil fertilizer amendments is not only natural but is also proven to be environmentally safer and financially more cost effective.

For human excrement and urine, to be separated and diverted in the first place, and then using energy from other sources (fossil fuels) and requiring human physical involvement to move/transport those known to be hazardous/unprocessed materials to some centralized facility for treatment/disposal/reuse or urine being humanly involved in spreading the urine for agricultural fertilization, to me is totally unnecessary.

When 90% of the issue of human excrement and liquid urine mass could and would have been taken care of ONSITE, simply through evaporation with a correctly designed vault/pit for air/oxygen to circulate and to let Mother Nature do her thing would, logically be the first choice in an argument for the treatment and conversion of toilet and organic wastes into RESOURCES effectively and efficiently.

If you are interested, we have just uploaded our video on You Tube at; Proven Environmental Water & Wastewater Solutions for Worldwide Health & Economic Development.



The Challenge from the Gates Foundation to "Re-invent the Toilet", is commendable but I do believe the Challenge should be concentrating on education and the acquisition of knowledge regarding what the REAL problem is! It is not the TOILET, it is the lack of KNOWLEDGE regarding the potential of resources from wastes if naturally and technologically respected and treated as such!

Buckminister stated that "Knowledge is Wealth" and therefore, I believe that we should base the Challenge of "Helping Humanity", on the need to re-evaluate our first premise in our conclusion that WASTES should be considered RESOURCES and recycled where they are created.

Instead of using mobile/vehicular energy wasting technology and/or copious amounts of water to transport materials that could naturally and technologically be converted onsite without any exhausted external sources of energy (fossil fuel) needed in transportation and/or water carriage would seem to me to be a first step in reducing the energy and water when compared to traditional/conventional/centralized methodologies.

Clint

The added files represent and explain blackwater and greywater treatment systems designed for warmer than Alaska/Minnesota climates. The greywater system is the same but the composter has been reduced in size by 50% with less complexity, cost, maintenance for warmer applications.

Clint

Remember that works in the long run in developing countries is simple. simple, simple. Try to use heat for ventilation. Usually a vent pipe exposed to the sun will create enough heat to cause air movement. This can be supplemented with reflectors or sheet metal to help concentrate the heat. Figure out how to work with nature.

Tore

+++++

Note by moderator: The discussion on some aspects of this process that followed here was moved to another thread as the topic changed to general fertiliser aspects:
forum.susana.org/forum/categories/205-ve...post-digesters#16786

How about melted plastic, flattened metal pop cans or whatever recycled into blades?

Better perforated, non-corrosive sheet of whatever, plastic preferred.

Decentralized, Natural, Recycling = Sustainability

Human Excrement + More carbon + urine = nutritionally complete solid soil amendment fertilizer for consumable crops.

Clint

Thanks very much Clint and Tore for your ideas and explainations!

I have also thought of a wine turbine for ventilation, but I think these are not exactly cheap. Let me find out at a local construction materials' market here in Germany. But would it be possible to manufacture them locally from sheet iron using simple welding tools? - I have my doubts.

I think we'll just extend the vent pipes to greater lengths, thereby increasing the draft they are exerting. And then, we'll have to replace the white textile on the floor of the chambers (on top of the gravel drainage) by something more durable and more permeable.

In my design, the composting was not a problem. The material (feces/leaves plus wash water) was composting well - no problem! During the resting period some water has to be added when it is getting too dry.

Cheers, H-A

You have a great system to compost human excrement. You need aeration and movement to allow the product to become compost.
You have to remember that we are talking about two different systems. You are composting and that takes aeration throughout the pile. At the end you will have compost that is decomposed feces.
What the UDDT does is to make the urine, which has most of the nutrients, quickly available to use on the crops. The urine is usually pure and if any pathogens are present it is usually in very small quantities. Sitting a week will kill anything present. The main concern to health is the feces. By dehydrating and heating for 6 months the pathogens are destroyed. The human fertilizer can now be tilled into the soil to strengthen, refurbish, and become compost.
With a proper ventilation pipe air is pulled from the interior, through the cracks and crevices of the base, and then up the ventilation pipe. I have not noticed any odors in a UDDT.

Dear H-A,

Sorry to take so long in getting back to you but I am on the road in Costa Rica at Manuel Antonio/Quepos.

This trip have been very good for enjoyment by getting out of the US and also informative about the water and lack of proper sanitation throughout Costa Rica. Very poorly designed septics and open grey water sewers and worse with the sewage pollution being dumped into the rivers. I do have my work cut out for me here as well as the rest of Central American with extreme water supply issues for developers especially not taking from the local Ticos.

As I continue to try to emphasize, even if you were utilizing a good carbon source properly according to your description of the air circulation I do not believe that your present slots and venting is at all sufficient.

I would suggest before you even start using the vault you MUST provide a French fry basket type of false floor configuration (a simple sheet of steel/plastic mesh with at least 1/4" openings supported from the bottom of the vault floor to suspend the now potential composting mass. Steel will eventually need to be replaced but it is available somewhere and cheap.

For the vent instead of a solar fan to be stolen just use an attic turbine ventilator or even more than one if local winds are not frequent.

The addition of the carbon source is essential. A person needs to add significant handfulls after each use, not just a cup full. Even though it may seem to be quite a bit, the correct carbon source will decompose if it is sufficiently moist, i.e. the addition of the urine, not wash water.

I also still contend that it is going to be much more cost effective and design effective to manufacture a polyethylene tank with a proper ventilation design and place it into the existing vault area to work properly. You can still build the building locally but trying to create an effective air circulation system utilizing local materials, concrete and wood, is not at all logical and or effective. My tank sections are 2' deep x 4' wide x 88" long. The tank contains two of these sections, a top and bottom, which bolts together to create a 4' wide x 4' high x 88" long complete tank with proper ventilation and access doors for maintenance and compost removal. These tanks fit into Cessna 208's Caravans and even smaller planes, pickup trucks, boats, dog sleds etc. and can be manufactured and shipped inexpensively.

If the composting process is set up correctly the system will compost and there will be NO odors. But the present EcoSan or any design constructed onsite I have seen so far is totally inadequate for proper composting. Without a proper design you will continue to have serious issues with local acceptance because of the odors as documented in various research projects results.

Forget the urine diversion and spend more energy on designing the system correctly instead of assuming that the excess liquid from urine is the problem. It is not the urine it is the design.

Clint

Clint, it's agreed that these toilets are not perfect, and they are open to improvements. At the same time, please keep in mind that an affordable cost for a family toilet may be around 200 Euro/dollars - that could a lot of times be more than 3 months' salaries.

I once tried a composting UDDT, which should really be called UDCT (urine diverting composting toilet, rather than dehydrating), where I took the UDDT design, but allowed people to wash on top of the feces hole. The toilet was equipped with a gravel drainage which was discharging into a canna bed (could be any water loving plant, like banana plants). Users were usually using crushed dry leaves as cover material. You'll find more information on that toilet at that link:
www.flickr.com/photos/gtzecosan/79802822...m-72157630727680876/

Here are photos of the drainage and the canna bed:

Public toilet cont'd by SuSanA Secretariat , on Flickr

Public toilet cont'd by SuSanA Secretariat , on Flickr

Unfortunately, we ran into a problem with odors very propably due to a lack of ventilation. In this connection, it should be noted that the four chambers (two for each of the two stalls) were connected inside at the height of the urine pipe, i.e. on the upper side of the chambers. And the so called heaters (covers) were oriented East, the toilet being located about 400 Km North of the Equator. What is not shown in the pics is that we added slots at the upper end of the cabin doors. In addition, the drainage was also able to provide some air from below.

Of course, we could have used fans at the upper end of the vent pipes, but that would have required a small solar system to be mounted on the roof of the toilet. And what I know about solar panels is that they are favorites of thieves. With a solar, the toilet would have required permanent security.

Clint, would you or anyone have an idea for a simple solution to that problem?

Cheers, H-A