Justifying composting toilets

  • Ecogo
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Justifying composting toilets

Hi,
I am developing homes in an eco-village subdivision in North America with toilets that meet North American cultural norms (no visible excreta, smell, min maintenance). Foam toilets may be a solution but difficult to justify cost with a 1% IRR.

I am looking for advice as to justifying UUDT or composting toilets here. Any insights, tools, protocol would be appreciated.

Thanks in advance.

David
David Burdick PE(WI), CEM, SHP, BPI, CPHC, LEED GA

Four Elements Engineering™

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  • JKMakowka
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Re: Justifying composting toilets


Krischan Makowka
Microbiologist & emergency WASH specialist
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  • joeturner
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Re: Justifying composting toilets

What do you mean by 'justify'? If you mean that you want evidence to show that UDDT systems meet local and federal hygiene rules in the USA, that might be difficult to do - and you are probably best discussing it with the local regulators.

PLUSH are probably a good place to start to find colleagues who are proficient with the local rules in North America.
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  • dorothee.spuhler
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Re: Justifying composting toilets

Dear David
Have a look here: www.cloacina.org
Or write to me and I can give you the email of the people behind this.
They are working on with Recode Oregon to legalize sustainability in the US. Last fall the international Association of Plumbing and Mechanical Officials (IAPMO) invited them to create a composting toilet code for their next edition of the Uniform Plumbing Code.
I am sure they can help you,
Dorothee

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  • AquaVerde
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Re: Justifying composting toilets

Sorry David,

I understand "Justifying" the SALE of an over engineered system with an unique (propriety) soap.

Please keep it much more simple! Less is more. Domestic "pipi & kaka" in this small amount do not need computer and energy demand. Nature will do it more simple.

Good Luck
Detlef

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Re: Justifying composting toilets

I think what the question really is, if there is a template economic analysis of EcoSan compared to other options.

WASHcost: www.washcost.info/ might have something, but under the specific setting that seems to be asked for I am not so sure if those will help.

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  • paulv
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Re: Justifying composting toilets

Some ideas for legal composting in the USA...

1. Change the regulations which currently prevent the use of UDDT and composting. However in high density urban areas, I'm not sure one can responsibly support this solution because some people may not properly treat/compost the waste, which could lead to a real health hazard.

2. Use a heat disinfection process which is automated, and designed for individual homes, apartment level or neighborhood level of treatment and seek approvals for the system technology at a national level.
Options:
2.a. transport and process waste in a water slurry through tankage and piping using a solar heat collector, then compost
2.b. move the waste bucket into a solar oven for heat disinfection, then compost
2.c. use outside source of heat to disinfect waste (hot water, microwave?)

I think 2.b fits the development Mr. Burdick is describing the best, although it creates limitations on the location of toilets in buildings.

The toilet is located near a solar oven (highly insulated shed with south glazing).
On a regular basis, the full solid waste bucket is automatically moved into the solar oven and an empty, clean bucket is replaced in the toilet. Temperatures are monitored in the solar oven, and when the waste has been heated to the appropriate temperature for the appropriate time, it is moved to a compost bin. The bucket is cleaned and ready for reuse.

Why automate this instead of doing it by hand? The main reason is that by removing the human element from the process, regulating authorities can have some assurance that all waste will go through the disinfection process. Any technology going through a review process will be held to a higher standard than current technology. It does not matter that a simple composting system is more reliable than municipal systems which overflow into rivers when it rains. It does not matter that a compost pile is better than a septic system that overflows liquid sewage into the yard when it is full. Any new system will be expected to perform without any threat of disease or negative impacts.

Automation also reduces human contact with the waste. Carrying the shit bucket can be demeaning to some people. The current water toilet system is very good at making waste go away with minimum effort. In order to make a system acceptable to all people, automation is important and worth the additional cost and effort, when people can afford it.

It is likely less expensive to install an automated heat treatment and composting system, together with a greywater system, than it is to install a septic system or connect to municipal sanitary sewer. This is potentially a disruptive technology which will not be lost on those who manage municipal waste water treatment systems. As lower cost disinfection/composting systems are installed by homeowners, the high costs of underground piping and operating a municipal WWT plant will be borne by fewer and fewer customers, raising fees and encouraging more and more use of the lower cost systems. So do not expect a warm welcome for this new technology.
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  • noe-hays
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Re: Justifying composting toilets

There's another foam flush toilet on the market now from Advanced Composting Systems (makers of the Phoenix composting toilet). They were installed recently in the five-story Bullitt Center in Seattle. They use an inexpensive soap, and I think they're considerably cheaper than the ones from Japan that were mentioned earlier in this thread, but there is a long lead-time on orders.

There is no information about this foam flush toilet online, but this is the manufacturer's website: www.compostingtoilet.com

--Abe
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  • ChrisBuckley
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Re: Justifying composting toilets

Greetings
With regard to your system analysis do not forget maintenance and power failure scenarios. At some stage there will be a break down and the system will need to be cleaned before it can be repaired. Consider what will happen to the system in the case of an electricity supply disruption?

Chris

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  • smecca
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Re: Justifying composting toilets

Right on Chris. This is why we are so focused on our GSAP Microflush toilet, an off-grid vermicomposting enhanced aerobic filter digester with the Microflush valve, which flushes on a cup of water from the previous user's handwash.
..Steve

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  • Ecogo
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Re: Justifying composting toilets

Thank you Dorothee, I will write you soon to further investigate.
cheers
David

Dear David
Have a look here: www.cloacina.org
Or write to me and I can give you the email of the people behind this.
They are working on with Recode Oregon to legalize sustainability in the US. Last fall the international Association of Plumbing and Mechanical Officials (IAPMO) invited them to create a composting toilet code for their next edition of the Uniform Plumbing Code.
I am sure they can help you,
Dorothee
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  • Ecogo
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Re: Justifying composting toilets

Thanks Abe, this is helpful.
Still trying to get the numbers to work out. May not be possible but would be good to get an IRR above 5%.
Would love to focus the conversation on ways to economically justify a composting, yuck free toilet for the masses in the US.
Cheers
David

noe-hays wrote: There's another foam flush toilet on the market now from Advanced Composting Systems (makers of the Phoenix composting toilet). They were installed recently in the five-story Bullitt Center in Seattle. They use an inexpensive soap, and I think they're considerably cheaper than the ones from Japan that were mentioned earlier in this thread, but there is a long lead-time on orders.

There is no information about this foam flush toilet online, but this is the manufacturer's website: www.compostingtoilet.com

--Abe

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