Overview
My version of a "sawdust toilet" (as described in the
Humanure Handbook)
consists of a receptacle bucket, a removable toilet seat that slips
into the top, and a bucket of sawdust for covering after each use. When
the toilet is full the seat is switched to the empty sawdust bucket. The
toilet is emptied, cleaned and sanitized and then becomes the sawdust
bucket after filling with clean sawdust. The whole toilet system,
including outdoor
compost
chamber, can be constructed for less than $10. This simple,
inexpensive, and hygienic toilet -- affordable to construct and maintain
by just about anyone on the planet -- is a perfect example of an
appropriate and
sustainable technology.
Materials
- Three or more plastic 5-gallon buckets (20 l)
- One toilet seat
- 6 wood screws
- 3 small pieces of wood that function as cleats (approximately,
1 inch (2,5 cm) wide by 3 inches long (8 cm) by 3/4 inch deep (2 cm)).
You will also need a compost chamber; mine is constructed from recycled wooden pallets held together by wire at the corners.
The seat with flange attached
Tools needed
Steps
- Using a wood saw, cut the top 4 to 6 inches off one of the
buckets. This will serve as a flange to which a toilet seat is attached,
allowing it to slip inside a second bucket. (See photo at left.) The
bottom part of the cut bucket can be recycled, for example as a planter.
- Attach this flange to the bottom of a toilet seat using two
screws at each of three wood cleats. One screw attaches the cleat to the
toilet seat; the second attaches the bucket flange to the cleat. (See
photos and drawings.) The four small brown objects in the photo, the
original toilet seat spacers, are removed and discarded. The completed
receptacle with flanged seat in place on a receptacle bucket is shown at
the top of this page.
- A second bucket contains sawdust, chipped wood, chopped straw,
cereal hulls, or other absorbent carbon-rich organic matter. Covering
with several cups or handfuls of this matter after each use effectively
prevents odors. (See photo.)
- When the receptacle bucket is full transfer the flanged toilet
seat to the now empty sawdust bucket which then becomes the receptacle.
Covering with organic material
- Empty the toilet contents into a composting chamber (see photo)
and cover with a fresh layer of sawdust to prevent odors and present an
aesthetic appearance. Clean the empty receptacle and sanitize and
freshen in sunlight. This bucket, after filling with clean material,
then becomes the sawdust bucket, and the cycle starts over. This step is
the only time when odors are present, and only momentarily. Although
not necessary, some individuals collect urine separately in a sealable
container (such as an inexpensive but sturdy plastic bottle) because of
its high value as a nitrogen source. It can be diluted by 5 parts water
and put directly on plants.
Emptying into the composting chamber
Closing the nutrient cycle
This simple composting toilet system is inexpensive both in
construction and to operate and, when properly maintained, aesthetic and
hygienic. By closing the human nutrient cycle, it is a perfect
compliment to
organic gardening.
In many ways it out-performs complicated systems costing hundreds of
times as much! Although it may lack appeal in first world countries with
their expensive, "out of sight, out of mind" sewage systems, it may be
highly appropriate in areas that lack such complex infrastructure.
However, there seems to be an explosion of interest in
sustainability, and many more citizens are coming to feel that
Composting Toilets are the Only Way to Go!
Ventilation
We recently tested a simple ventilation system to capture odors
during use and vent them outdoors. This common-sense, basic capability
is something lacking in almost all toilets, even in the wealthy
industrialized countries. The American approach is to ventilate the
toilet room by a fan installed in the ceiling. This makes some sense, as
this approach will also ventilate a shower or bath. However, a much
more effective approach, which prevents any odors from even escaping
from the toilet, is to ventilate the toilet itself. You can achieve this
by attaching a flexible air suction hose to the toilet flange powered
by an electric fan which sucks air from the room and vents it either
into the normal ventilation stack or through the wall to the outside.
Our simple contraption consists of a second hand vacuum cleaner, a
2" check valve to prevent odors or outside air from flowing backwards
into the room, a dimmer switch to lower the power (and therefore noise)
of the vacuum, and a few pieces of 2" or 3" pipe to route the air flow.
Total cost is less than $35 (vacuum: free, check valve: $17, other
plumbing parts for routing air: about $5, dimmer switch and other
electric parts: $10). The fan device is actuated for only a few seconds
during use, until new deposits are covered when no further odors are
present. This method works flawlessly and prevents all odors, all the
time. For those who don't want to re-invent the wheel, I have come
across a
commercial version of a toilet ventilation fan,
although I cannot vouch for whether it works well. Basically, it
appears to be a thin device that fits between the usual toilet seat and
the porcelain fixture. It ventilates air in its proximity with an
electric fan. The following simple diagram shows the basic plan for this
toilet (not including the ventilation device). The air suction device
(connection by some type of flexible hose) attaches to anywhere on the
flange.
No comments:
Post a Comment
Do To the enormous amounts of spam I will no longer take the time to moderate Anyone posting under anonymous... Sorry for the inconvenience but my email is blasted everyday with 40 to 50 anonymous posts that are junk mail. I just don't have the time to read each one before deleting.