[permaculture] Compost Riddle..
christopher.nesbitt at mmrfbz.org
Fri Nov 20 13:08:15 EST 2009
We use a Vietnamese style double vault latrine with two stalls over
each of two chambers. The chambers are next to each other, sharing a
common wall, and have a 3 inches cement slab on top. They are roughly
10x10x8 feet, and take two or three years to fill. The chambers are
vented through the roof with a 4 inch pipe. The structure above the
chambers is built with wood, two stalls over each vault, and from the
thrones, one has an inspiring screened view into the agroforestry
system. Bird watches love to sit there.
Like other double vault latrines, one chamber is filled at a time.
After each deposit, a few handfuls of rice hulls or saw dust (and the
occasional bucket of fresh grass and bamboo leaves) is dropped down
the hole. This keeps the carbon/nitrogen ratio balanced.
The issue your are seeking to address, dealing with urine, we dealt
with by deciding against a urine separator, and increasing the amount
of rice hulls. Any urine separator will need to have a way to deal
with the urine, too, and collecting it would not be culturally
palatable here (mostly Kekchi and Mopan Maya communities, but also
Mestizo, Creole, Garifuna and East Indian). Simply add more organic
matter to help soak it up. This avoids the disposal/treatment issue of
the urine. By charging the bottom with a permeable layer of soft wood
branches (we used cecropia and bursera), you allow air to circulate,
and a way for the moisture to evaporate a bit.
As long as there is enough rice hulls/sawdust/bamboo leaves, there is
never much of a smell, even with the urine, and never a strong shit
smell. Even when we have 40 people on site, the smell is minimal.
When one vault is filled, it is capped off, and the other is started.
By the time the second vaul it filled, 2-3 years have elapsed and the
first vaiult is composted and can be applied to gardens, ornamentals,
etc. The hot composting kills any possible parasites or fecally
This design has been replicated in several local schools.
If you happen to end up in Belize, please come visit and see it. I
keep meaning to post pictures of it on our website, but have not. A
reminder to do so! I think somewhere in the FB group there is a photo
of it http://www.facebook.com/group.php?
v=photos&ref=ts&gid=34801950118 If not, write me off list and I can
email a few.
Maya Mountain Research Farm
San Pedro Columbia, Toledo
PO 153 Punta Gorda Town, Toledo
On Nov 20, 2009, at 10:26 AM, michael judd wrote:
> Fellow Permaculturists,
> I have a compost toilet riddle that needs a little collective design
> input in support of our brothers and sisters down in Nicaragua. As
> part of two upcoming service and ecology trips Project Bona Fide is
> heading up we are going to build a multi chambered compost toilet at
> Mano Amiga community center on Ometepe Island.
> The outline of the toilet design is: two chambers for good 'ol #2
> and an additional section as a urinal. Now, the latter is the crux
> of the design challenge as manual collection is not an option nor is
> an managed mix of #1 . Thus the riddle..
> Hoping that some of you have come across or built unique solutions.
> Michael Judd
> Founder, Co-Director
> Project Bona Fide
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