Part 23 - cd3wd423.zip - Offline

Part 23 - cd3wd423.zip - Offline
MlCFtOFlCHE
REFERENCE
LIBRARY
A-ptoject of ?Nmteers in Asia
e
Published by:
National Center for Appropriate
P.0. BOX 3838
Butte, MY?59701 USA
Technology
Paper copies lrrre $ 3,00=
Available from:
National Center for Appropriate
P.0.
Butte,
Box
31838
HT 59701
Technology
WA
Reproduction of this microfiche document in any
form is subject to the same restrictions
as those
of'the original
document.
A Guick
for
tIhwuzr=buiMrs
National Center for Appropriate Technology
PO. Box 3838
Butte, Montana 59701
406-494-4572
:
TABLE OF CONTENTS
t
introduction
1.
Overview
A.
8.
C.
0.
E.
F.
II.
C.
0.
E.
III.
the
tomposting
Process
I
1
2
introduct
ion
A Biological
Process
Composting:
Compost Toilet
vs. Compost Pi 18
Composting Considerations
for Compost Tol lets
1. Household Sewage Descri pt ion
2. Carbm/Ilitrogen
*Ratio
3. Aeration
4. )bistuts
5.
Decomposing Organisms
Health
lmplicatlons
of Compost Toilet
Usage
The Potential
Problem
I.
Preventing
Disease Transmission
in
2.
Compust Toi lets
Sunnary and Recommnendations
Overview
A.
B.
of
of
bupost
Toilet
A.
I:
0.
E.
F.
6.
Appendix
Rtferences
Owner-Built
:
f
5
8
10
Design
13
13
13
14
14
15
introduction
General Design Considerations
1. Design Criteria
Basic Designs Reviewed
Design
1. Slant-Bottom
2.
Drum Privy Design
3. Vault Privies
+
4. Appl i awe-Type
Designs
5.
Design Research
Construction
Par-ters
1. Sizing
Dui lding Hatertals
2.
3. cost
Design Problems and Solutions
I.
Insects
2. Liquid
Build-up
3. Emptying and Handling
4. Aeration,
Odor, Fire
Selected
‘_
3
N
:i
19
20
20
21
22
22
22
23
25
25
Systems
Introduction
Wood frame Composting
Si t-ibun
John
The Haine Tank
Batch C-poster
Bin Composter
Bio-Recycler
A- Construction
Details
Compost ing Toi let
28
29
Toilet
:1
;i
40
for
Uood-Frame
42
51
2.4:
2.S:
Food Chain Diagram
Aerobic
Decomposition
of Organic Matter
Slant Bottom Compost Toilet
Design
Own Privy
Double Chambered Box or Vault Privy
Appliance-Type
Deslgn
Suggested Drain System
Wood Frame Composting Toilet
Sit-Down John
Urine Diverter
for Sit-Down John
The Haine Tank
Second Floor Appl icat ion of Haine Tank
Batch Unit Design
Bin Composter
Bio-Recycier
Tab les
1 .:
2 .:
;:;
tlousehold
Waste Categorles
C/N Ratios for Organic
Materials
Examples of Fecal-Borne
Diseases
Thermal Death Points of Some Cornnon
Pathogens and Paras i tes
9
Why use a compost toilet?
The reasons most often mentioned are water
conservation
and elimination
of *water pollution.
The flush toilet,
long considered
the symbol of modern sanitation
and progress,
wastes approximately
40 percent of all water piped into the home.
in recent years,
the demand has
escalated,
leaving
that resource
increasingly
scarce in some regions.
The
waterless,
or compost toilet
can save from 25-60 gallons
of water per person
per day.’
A second consideration
is waste recycling.
The decision
was made, years
ago, that water would serve as a sewage disposal
medium; that choice
is
becoming a heavy social
burden.
American taxpayers
spend billions
of dollars
each year on sewage treatment
facilities.
As water use increases,
treatment
plants
get bigger and yet the technology
is hard-pressed
to keep up with the
volume and types of wastes in our disposal
water.
On-site
waste treatment
and recycling
through
conpost toilets
cou”sd partially
alleviate
the strain
on these facilities.
Of course,
disposal
needs.
back-up systems
What’s more, the
the reach of far
composting
toilets
fill
only a small gap in regional
waste
After
all,
such systems must necessarily
be accompanied
by
to handle other waste water (i.e.,
tub, shower, sinks).
cost of these alternative
toilets
is still
high, and beyond
too many people.
Nonetheless,
there is sufficient
need to develop suitable
designs and
encourage
the use of waterless
toilets
in areas where they are appropriate.
One way to make the technology
cost-effective
is to design and build your
own system.
in each,individual
case, the relative
value of using a compost toilet
must be determined.
This value varies
with environmental
conditions
and
personal
lifestyles.
For example,
in a rural
setting
where septic
tanks and
leach fields
are not feasible,
the cornposting
toilet
can be extremely
valuable.
But using a compost toilet
in.a New York City apartment
#nay not be practical.
Using such a toilet
is not a simple exercise.
Where we are used to convenience,
this alternative
entails
work.
When is the compost toilet
the most efficient
option
for human waste
treatment?
Efficiency
entails
more than saving water and recycling
wastes;
it involves
public
health
as well.
Most societies
choose a water sewage treatment system for more reasons than convenience.
The potential
for disease
borne and bred in human wastes is great.
Compost toilets
are imperative
and must be part of the efficiency
rating
for this alternative
technology.
A compost toilet,
as this guide points
out , can be a safe and efficient,
The main question
facing owner/builders
sanitary
human waste treatment
system.
is whether they are prepared
to take the time to manage the system efficiently.
We assune that our reader has already
examined his or ner need
compost toilet
and determined
the purposes for its use.
Our primary
to identify
the important
construction,
installation,
and maintenance
Our goal is to put the
considerations
relative
to compost toilets.
in a better
position
to manage the, decisions
and subsequent
tasks of
toilet
use.
i
for a
aim is
reader
compost
The theme of Section
of human wastes through
the process in order for
outdoor cunposting
pile
the health
implications
In Section
Ii, basic
prospective
-r/builder
construction,
installation
I is process:
the composting
process;
the breakdown
natural
decomposition;
and effective
management of
decomposition
to occur.
The difference
between an
and a compost toilet
is clarified
and, most importantly,
of compost toilet
usage are examined.
compost toilet
designs are reviewed.
Here the
is introduced
to problems that may arise
in the
and/or maintenance
of compost toilets.
Section
II1 cites
the valuable
experience
of other users.
Last year,
the National
Center for Appropriate
Technology
conducted
a survey of compost
tot let -r/bui
lders.
The results
of that survey,
presented
in Section
Ill,
indicate
what other people are doing in the field
of owner-built
compost toilets.
The authors
do not inter&
this Guide to be the definitive
work on compost
toi lets.
It is written
to promote information
development
and exchange.
Alternative
hunan waste disposal
systems are an emerging technology
in which
Modifications
and improvements
in design,
as well
mOre research
is needed.
The authors
hope this
as reductions
in cost, could spur greater
public
use.
Guide will
instigate
canmunication
and feedback among researchers
in this
field,
and help get individual
owner/builders
started
on the right
track.
CREDITS:
Ida Daniels
is a Recycling
Specialist
in the Research and Development
Division
of the National
Canter for Appropriate
Technology.
Robin Billau
is
a Life Scientist/DSRA
Specialist
for the Montana Energy and HHD Research and
Developncnt
Institute
(HERDI), working
under contract
for NCAT. Also under
an NCAT contract
is Jon Averill,
a native
of Hinton,
West Virginia,
who has
Editing
was
extensive
experience
as an owner/builder
of compost toilets.
perfonued
by NCAT Technical
Writer
Jon Sesso; Technical
Illustrator
was
UaIly Hansen.
The authors
would like to thank draft
reviewers
Zandy Clark of Bath,
Haine, and Patti
Nesbitt
of Strasburg,
Virginia,
for their
assistance.
Also,
special
thanks go to the following
individuals
and organiratlons
for the use
of their
graphic
designs
in Sectlon
Ill:
R. E. Leonard and S. C. Fay,
Northeastern
Forest Exparlmntal
Station,
(U. S. Forest Service);
J. F. Ely
and E. L. Spencer, Appslachim
Mountain
Club; J. F. Criss,
Blo-Recycler;
Zandy
Clark;
and Peggy Hughes, Maine Compost.
1. OVERVIEU OF THE COB4P'ZlING PRC)CESS
A.
Introduction:
In this section
a brief
but concise overview
of the composting
process
is provided,
with special
considerations
relative
to compost toilets.
The
biological
process
involved
in composting
organic
wastes is reviewed and
the differences
between a “*compost toilet”
and a “compost pile”
are clarifi’ed.
Finally,
the health
implications
of compost toilet
usage are examined.
A compost toilet
owner, builder,
or user must be critically
aware of
many important
factors.
Because of the potential
health
problems associated
with human excrement,
special
precautions
must be taken in all stages of
compost toilet
use.
The user must understand
the degree of maintenance
required
for a compost toilet
to function
properly.
The user must take
time to learn health-safety
precautions
and how human wastes are transformed
into a manageable end product
through
biological
decomposition.
A compost
toilet
may be a safe, environmentally
sound alternative
to the flush toi let
but only if constructed
and maintained
correctly.
B.
Ccnnpost i ng :
A Biological
Process
Generally,
%ompostl’
is a mixture
that consists
largely
of organic
matter.
The organic
matter
undergoes a chemical
and physical
change--natural
decomposition
through
biological
action.
The result
is a reduction
in the volume
of matter and an end product
that has been used by some as a soil conditioner.
(However, NCAT cannot recomnd
this use unless the end product
has been
proven safe without
additional
heat sterilization.)
helps
A lo& at the
to illustrate
Figure
1.1
food chain,
one of the elementary
the composting
process.
principles
of biology,
Every living
thing
is reduced to its organic
and inorganic
constituents
organisms
(also called
saprophytic
organismsj.
by decomposing
These
organisms
include
a variety
of fungi,
bacteria
and protoro.1.
To live,
saprophytic
or deccnnposing organisms
must utilize
carbon from other sources
(namly
organic
material).
They cannot take energy from the sun and use
it as green plants
do through photosynthesis.
More simply put, the
decomposing organisms
eat and live offorganic
matter.
Some types of
have complex nutrient
needs, and in
organisms
such as act iGiiycetes,
additron
to carbonaceous
compounds
(i.e.
straw,
dry leaves)
they are able
to decampbse (or eat) a variety
of other substances
found in compost
toilets
and piles.
Two types
of decomposition
can occur:
Anaerobic
and Aerobic.
Anaerobic
decomposition
occurs without
the presence of oxygen,
like the
decomposition
that occurs in swamps-c
tanks,
cesspools,
or the bottom
of a garbage can when it hasn’t
teen emptied for a while.
The foul-smelling
-&r
fr a result
of the production
of chemical
by-products
which are produced, along with organic
acids,
ammonia, and methane by anaerobic
bacteria.
#s heat is liberated
in the anaerobic
decomposition
process.
Aerobic
decomposition
utilizes
oxygen in the decaying
process and no
-.<CFsting
is aerobic
decomposition.
The simplified
odor is generated,
how osnatter
1s decomposed Into its
equation
in Figure L epicts
organic
and inorganic
constituents
by decomposing organisms.
Figure
C.
1.2
Compost Toilet
There are
compost toilet
names.
vs.
Compost Pile
several
critical
differences
that tend to be overlooked
between a compost pile
due to the similarities
and a
in their
The basic difference
is that the compost toilet
uses a high volume of
The potential
disease factors
human wastes and the compost pile uses none.
to use a toilet
design
assoc:aecd
with human excrement
make it necessary
which minimizes
the handling
of waste.
2
The presence of human wastes in the process places important
constraints
on the use of the end product
from a compost toilet.
A canpost pile
is
basically
a waste recycling
system;
it is usually
built
with the express
purpose of recycling
organic
wastes.
Periodic
turning
of the collected
waste IS part Of regular
maintenance
to achieve
proper aeration
and insure
that all areas of the pile are heated.
The pile
is maintained
in this manner
to insure that the end product
can be used safely
as a fertilizer
or soil
conditioner.
A compost toilet,
on the other hand, is basically
a waste treatment
Its main purposes are to save water and reduce the volume of human
sys tern.
wastes with on-site
treatment.
Little
research
has been done addressing
the pathogen content
of the end producti from a compost toilet.
While
certain
individuals
generally
regard the end product
as a safe soil conditioner
for residential
lawns and ornamental
plants,
the safety of this
practice
has not been proven.
Likewise,
its use as a fertilizer
for foodproducing
gardens is questionable
as the potential
for disease transmission
remains unclear.
HaJever, while
there are major differences
between a compost toilet
and
there are also similarities
between
pile that require
special
precautions,
It is a good idea for individuals
to experiment
with the process
them.
of building
outdoor
compost piles
or using indoor composting
bins to acquaint
themselves
with the composting
process.
Start off by using plant materials
and animal manures only.
Heat, dead animals,
or human excrement
should never
be used in a compost pile because of the danger of introducing
harmful orOnce the process becomes familiar
and an odorless,
bioiogicaily
ganisms.
balanced pile has been built
that results
in a humus/soil-like
end product,
the basics required
to build and maintain
a compost toilet
should be
understood
enough to consider
trying
a canposting
toilet.
0.
Conpostinq
Considerations
for
Compost Toilets
Through the experience
gained in building
an outdoor
compost pile,
you
will
learn the importance
of layering
the wet, green, nitrogenous
materials
with the dry; brown carbonaceous
materials
to provide
a balanced diet for
the decomposing organisms.
Air and water are also necessary,
6s well as
soil or old compost (to innoculate
the pile with the decomposers).
These
ingredients
are the basic necessities
for the cornposting
processes,
whether
it be outside
or inside,
or on a large or small scale.
Carefully
attend
to balancing
these biologic
requirements
to keep your indoor compostlng
toilet
in gcod working
order.
1.
sonal
laajor
Household
Sewaqe Description
Before building
a compost
household
waste categories.
categories:
TABLE I:
it
toilet,
Household
is a good idea to identify
waste can be divided
into
HOUSEHOLDWASTE CATEGORIES
Definition
Black
Waste2
Examples
Any material
normally
of through
the toilet
disposed
Urine,
paper,
feces,
toilet
tampons
Grey Waste’
Other household
wastes normally
disposed of through
plumbing
fixtures
Laundry water,
shmer water)
garbage-disposal
Solid
All other household
normally
transported
Cans, glass,
waste
plastic,
etc.
Waste
perthree
wastes not
by water
3
bath and/or
sink water)
water
paper,
It is important
to renmmber that a ccmnpost toilet
will
black waste and organic
solid waste such as fruit
peelings,
grounds,
etc.
Therefore,
other maans must be available
for
grey waste’ and non-organic
solid waste.b
2.
Carbon/Nitrogen
only handle
egg shells,
coffee
dealing
with
Ratio
food for decomposers must be in balanced
For optimum composting,
proportions
for rapid reproduction.
Onr? way to maintain
the right
nutritional
balance
is to monitor
the ratio
of carbon to nitrogen
in the organic
Carbcn 1s utilized
as a source of energy by the
matter
to be decanposed.
while nitrogen
decomposing organisms,
is used in building
the protein
necessary
in cell
structure.’
About 20-25 times more carbon 1s needed than nitrogen.’
If there
is an excess of nitrosen.
the carbon will
be used up before the composting
is finished
and the extra nitrogen
will
be wasted.
-Odor is a key clue he;e
as the loss of waste nitrogen
can be detected
by the odor of ammonia escaping
When carbon is too plentiful,
all the available
nitrogen
will
from the pile.
be utilized
before the organic
matter
is thoroughly
digested.
The material
Besides providing
can still
be broken down, but the process is much slower.
a source of energy and balancing
the diet for decomposing organisms,
the
addition
of carbonaceous
material
prevents
compaction
by increasing
the air
spaces in the mass.
With specific
regard to maintaining
the C/N ratio
in a compost toilet,
a few facts should be considered.
first,
the nitrogen
content
of black waste
is high, Minly
because of the high nitrogen
content
of the urine.
Secondly,
feces and fresh kitchen
wastes,
also thrown into a compost toilet,
are
relatively
high in nitrogen.
it is important
to add sufficient
Therefore,
amounts of carbonaceous
material
to insure that proper compoxng
Is
acconpl i shed.
For example,
a 180 pound adult male’s daily
excrement output
is about
one (1) quart of urine and approximatelyont+half
(+) pound of feces.”
Also,
a household
will
accumulate
a daily
amount of organic
wastes (i.e.,
leftover
vegetables,
fresh fruit
peels).
Remembering that the optimum C/N ratio
for
proper composting
is 30:1, a significant
amount of carbonaceous
material
Dried leaves,
dried grass clippingf,
is needed to balance
the nitrogen
content.
hay, and straw are good carbonaceous
supplements
to the hlg)llynitrogenous
content
of human wastes.
It’s
of organic
more wet
clippings
a variety
Use what
binations
good to remember that,
to a certain
extent,
the carbon content
drier
wastes - higher carbon;
materials
is a function
of moisture:
- lower carbon,
mOre nitrogen.
For example,
fresh cut, green grass
Remember ,
will
have a higher
nitrogen
content
than dried clippings.
of wastes and layering
these wastes are key to the right
C/N ratio.
is available;
soon you will
have a sense of what kinds of waste comwork best in your toilet.
4
I
I
Table 2 shaws the C/N ratios
for
to a uwnpost toilet’s
ecosystem,
should be considered
nitrogenous,
carbonaceous.
Example
Urine
some co-n
organic
materials.
Relative
materials
with less than a 3O:l ratio
whereas over 3O:l should be considered
TABLE 2:
C/N RATIOS FOR ORGANIC HATERIALS’
1:
is approximately
14% C
C/N = 0.8:1
178 N
e
For every 0.8 parts carbon,
there
is one (1) part nitrogen
69% Other (Potassium,
Phosphorous,
Example 2:
Feces is approximately
etc. )
48% C
C/N = 6:1
. For every 6 parts
there is one part
e
6% N
46% Other (Potassium,
Phosphorous,
etc.)
Urine
0.8
3:l
6-10 : 1
Raw Garbage
(eggshells,
peels)
Dried
Grass
Cl ippings
Green Grass Clippings
12 : I
Whert
St raw
Tobacco
13 : 1
Rot ted Sawdust
208 : 1
14 : 1
Wood Chips
800 : i
Blood
Feces
Farmyard
Manure
Seaueed
3.
: i
carbon,
nitrogen
25 : 1
19 : 1
128 : 1
19 : 1
Aeration
Another key requirement
for effective
composting
is air.
It is imperative
that the entire
pile
(or toilet
chamber) receives
suffic=
quantities
of
air to support
the decvsing
organisms.
If optimum aeration
is not maintained,
the composting
process will
turn anaerobic
and slow down.
Odor will
develop
from the toilet
throne
if there is poor aeration
or poor ventilation.
Outdoor compost piles
are usually
aerated
by manual or mechanical
turning.
Likewise,
indoor compost toilets
require
some means of keeping the pile from
going anaerobic.
As mentioned
before,
adding carbonaceous
organic
matter
is
one way of providing
sufficient
air while eliminating
compaction.
Sane toilet
designs
include
a mechanical
turning
device for pile aeration,
other designs use air-fed
sloping
floor
inclines
to areate
the organic
contents
slowly
as the material
slides
to the front
of the chamber.
The potential
for
disease transmission
with toilet
contents
requires
that manual handling
be
minimized
and preferably
eliminated.
Those designs
requiring
frequent
manual
handling
are not recommended.
4.
Moisture
There is ZI delicate
balance between air and moisture
in the cornposting
Too
much
air
results
in
a
too
dry
pile,
while
too
much water
process.
results
in poor aeration.
Excessive
moisture
will
result
in liquid
pooling
at the bottom of the (toiTet)
container.
It wi!l
also cool the pile as the
accumulated
1 iquid takes away the generated
heat, and encourages
anaerob i c
conditions.
Flack waste has a high water content,
therefore,
it is necessary
to consistently
add dry carbonaceous
material
to reduce wetness to a moist,
Adding the dry material
on a regular
basis
slightly
dani;c-dry condition.
after
the addition
of black waste is an effective
method for moisture
retention.
Likewise,
the elimination
of urine
in the toilet
will
solve
large water content
problems.‘O’”
A too dry compost pile,
on the other
slow down and, in the case of the smaller
the pile wi 1 I harden.
heating
elements,
hand, wiii
commercial
cause decomposition
to
compost toilets
with
After obtaining
experience
with building
compost piles
using only plant
Maximum
material,
you will
be able to judge optimum yisture
content.
If moisture
drops below
moisture
content
for wastes is 55-65 percent.
dryness will
become a limiting
factor
in the decomposition
45-50 percent,
Generally,
compost should look damp when turned.
process.
5.
Decompos i ng Organ i sms
Me purpose of a compost pile
is to‘simulate,
as closely
as possible,
It is here that organic
the same ecology
that exists
in the top layers of soil.
material
is decomposed by saprophytic
organisms
for use in the food chain.
Fungi are very useful
organisms
in a compost pile
(or toilet
chamber) and
are generally
found in the cooler
outer layers of the pile,
along with the
actinomycetes
(which closely
resemble fungi
in appearance).:
Colonies
of
actinomycetes
give soil and properly-prepared
&ompost the smell characteristic
of frtshlv
turned earth.‘*
These oraanisms
also oroduce antibiotics.
the most
familiar
of which is streptomycin
pr;duced
by the-genus
Streptomyces:
The
antibiotics
produced from these organisms will
appear later
in the discussion
of preventing
growth of human pathogens
in compost toilets.
Actinomycetes
will
grow in the cool outer
layers of the compost pile and,
together
with fungi,
appear as grtyish-white
threads covering
the pile.’
Ctlluiose
and lignin
(carbon compounds which are particularly
resistant
to
decomposition),
are decomposed by actinomycetts
and fungi
in the latter
stages of the canposting
process.
Bacteria
are the other soil organisms
that are important
in comporting,
Speed and
and, because of their
numbers, they do most of the decomposing.
effectiveness
of the decomposition
process depends on the type of bacteria
involved.
Decomposition
occurs most rapidly
at high temperatures
which
Therefore,
bacteria
are grouped
support a certain
group of organisms,
according
to the temperatures
at which they are found.
at the beginning
of decomposition
Hesophilic
bacteria
are found prtdominantlrs
Thermophilic
bacteria
(heatwith an optimum temperature
range of 77-lO4OF.
loving)
begin to thrive
and soon proliferate
at temperatures
between 122-131°F.
Insulating
qua1 ities
of a certain
size
trap the heat generated
by these organisms.
able to retain
heat and support
thermophilic
rapid decomposition.
pile
(one cubic yard or
The center of the pile
bacteria
which results
larger)
is then
in more
Many other types of organisms
which live off of the saprophytic
organisms
are found in soil and compost piles.
Host visible
are the many types of
insects.
Host of the insects
present
in a compost pile are a natural
development
of the food chain and should be encouraged
by careful
maintenance
of the compost envi ronment . Other insects
such as flies
can be a nuisance
and, more seriously,
in the case of the house fly,
carriers
of pathogenic
organisms.
Spiders
are useful
in controlling
unwanted fly populations
and
are also essential
parts of the food chain.
E.
Health
Implications
of Compost Toilet
Usage
Historically,
it was a major triumph
in public
health
to be able to use
hunan waste treatment
to prevent
many infectious
diseases.
Primarily,
waste
treatment
involved
preventing
human wastes from contaminating
the soil and
drinking
water supplies.
Thus, the flush
toilet
was developed.’
The use of
compost toilets
as an alternative
to the flush toilet
has raised serious
health
considerations.
Many unanswered questions
remain regarding
the
management of compost toilets
and the effects
of their
use on public
health
These questions
are the major reason for the reluctance
of local
and safety.
health
departments
to allow the installation
of such alternative
toilets.
While states are naw re-examining
their
building
and health
codes to allow
for greater
use of compost toilets,
such systems are still
considered
experimntal.
I’ 15; In order to convince
local health
authoritlts
of the feasibility
of using a comost
tollet
to treat
wastes,
and more importantly,
to protect
the health
of the owners and their
neighbors,
Lt is imperative
that the
mmer-builder
understand
and address accordingly
the health
implications
*
of compost toilet
usage.
1.
The Potential
Problem
Tke goal in using a compost toilet
is to insure
that disedje
transmission
or hand1 ing of the final
product.
does not occur during
use , maintenance
Sanitary
management of feces is critical
to maintaining
a healthy
population.
chemkal
by-products
of the pollutants
Feces contain
undigested
food substances,
we art subJected
to or Ingest voluntarily,
and a variety
of bacteria,
viruses,
protozoa
and paresItes
that occur naturally
or as a result
of infection.”
Healthy
tndivtduals
also harbor many pathogens
in their
gastrointestinal
tracts;
Examples of fecal-borne
diseases
art listed
below in Table Three.
TABLE 3:
EXAMPLES OF FECAL-BORNE DISEASES’ ”
Agent
Disease
Bacteria
Baci 1 lary Dysentery
Typho i d Fever
Cholera
P rototoa
Amoebic 0ysenter.y
Flagellate
Diarrhea
Pa ras i tes
Ascariasis
Trichuriasis
Giardiasis
Vi ruses
infectious
.
7
Hepatitis
c
Urine is relatively
harmless compared to feces,
However, it
toxicant
or pathogen-free.
If an individual
has been exposed to
chemical
(such as arsenic),
the chemical
is primarily
eliminated
Also,
infections
of the kidney,
urine.”
bladder,
or other parts
urinary
tract
will
contaminate
urine excrement.”
Finally,
urine
inated when exposed to skin as it leaves the body.20 21 Therefore,
mandatory
that urine also be treated
before disposal.
the
The transmission
of disease
following
factors:’
22
1.
2.
3.
4.
5.
6.
upon the existence
of all
of
Agent of the disease
(cold virus)
Source of the infection
(another
human)
Mode of escape from the source (sneeze)
Mode of transmission
from the source to the host
(air-borne
droplets)
Mode of entry
into the host (person breathes
in contaminated
droplets)
Susceptible
host (contaminated
person’s
resistance
is low)
Absence cf one of
disease.
On dealing
disease prevention
is
to the host, that is,
prevent
contamination
2.
is dependent
is not
a toxic
in the
of the
is contamit is
Preventing
the above factors
will
prevent
transmission
of
with feces and urine,
the most practical
method
eliminating
the mode of transmission
from the
isolation
and sanitary
dis osal of the wastes
of soil,
food, water,
etc. t
Disease
Transmission
the
of
source
to
in Compost Toilets
Theoretically,
a compost toilet
should be designed
to isolate
and
render harmless the pathogens
that are associated
with excreta.
lsolat ion
occurs by enclosing
the wastes in a container
and preventing
diseasetransmitting
vermin or insects
from entering.
Ideally,
the toilet
should
eliminate
the necessity
of handling
contaminated
material.
The theory
behind pathogen reduction
in a compost toilet
centers
around three factors : heat, bactor!si’interaction,
and time.’
”
Heat is
a direct
consequence of the c=sting
process.
The heag
metabol ism at
by the organisms engaged in the
the center of a compost pile
is generated
decomposdt ion process.
Temperatures
in the center of the pt le can reach
over 131 F, which exceeds the thermal
death points
of many pathogens
(Table 4).
Houtever, slant-bottom
type cdmmercial.compost
toilet8
have no provisions
f8r
waste, pasteurization.
They never get hotter
than 90 F, and seldom over 70 F.
8
THERMAL DEATH POINTS OF SOME COMMONPATHOGENSAND PARASITES’
TABLE 4:
Organism
Thermal
Death
Points
Salmonella
typhosa
No growth beyond 115’F. death
minutes at 131°F to 14i°F.
Salmonella
spp.
Death within
one hour at 133’F* death
within
15 to 20 minutes at 14O*F.
within
Shi gel la spp.
Death within
Escherichia
Most die within
one hour at 13b°F and
within
15 to 20 minutes at 140 F.
co1 i
Endamocha histolytica
Thermal
Taenia
Death within
saginata
Trichinel
la spiral
Necator
amer i canus
is
larvae
death
one hour at
point
five
is
30
13l’F.
154OF
minutes
at
16O’F.
Infectivity
reduces 8s a result
hour exposu r& at 122 6; thermal
point
is 144 F to 162 F.
at
of one
death
Death within
50 minutes
Brucella
abortus
(or suis)
Death within
three
llicrococcus
pyoqenes
(var. auereus)
Death within
10 minutes
at
122’F.
Streptococcus
pyogenes
Death within
10 minutes
at
129’F.
Hycobacterium
tuberculosis
Death within
or momentary
15 to 20 minutes
heating
at 153’F
Mycobacterium
diptheriae
Death within
45 minutes
minutes
at
113’F
at
142’F
at
15i°F
13l’F.
In much of the literature
on compost toilets,
it is stated
that it
is the generation
of this pasteurizing
heat that theoretically
insures
the
sanitary
aspects of a compost toilet.
However, as is emphasized by Cooper
and Golueke,”
it cannot be assured that every pathogen
in the pile will
be subjected
to high temperatures
or that the exposure
time will
be sufficient
to kill
100 percent
of the pathogens,
The pile must be of sufficient
size
to insure heat insulation,
and the moisture
and nutrient
(C/N) balance must
be maintained.
However, it is virtually
impossible
to assure that all of the
pile will
be subjected
to these temperatures
and pasteurized.
even with freauent
turning.
Therefore,
it becomes important
to consider
bacterial
interaction
and tirae when discussing
the safety
of the toilet’s
end product.
Bacterial
interaction
includes:
competition
between the organisms
involved
in decomposition
and the less well-adapted
pathogens;
and antibiosls,
the process by which many of the fungi and actinomycetes
involved
in cornposting
produce substances
that kill
many pathogens.
One year is
the minimum figure
for retention
of human waste in a well-maintained
compost
toilet
to insure sufficient
reduction
of pathogens.”
Time is really
the
most important
factor,
The
as it compensates
for bacterial
interaction.
longer the pathogens
remain in an alien
environment,
the more likely
that
their
numbers will
be reduced because of a lack of suitable
nutrients
and a
suitable
envi ronment necessary
for propagation,
9
Disease transmission
by insects
is another
important
consideration
in
No matter how insect-proof
you attempt
to make
building
a compost toilet.
there is always one entrance
for them - the toilet
seat hole.
your toi let,
The major insect agent in the transmission
of the disease
is the house fly.
The house fly lays its eggs in and feeds on excrement
and, in doing so, picks
up pathogenic
organisms
on its body and legs and by digesting
infested
All must be
other flies
may also live on excrement.
g Various
material.
Flies are attracted
controlled
to prevent
personal
and public
health
problems.
Dark
areas
or
dark
surfaces
are
utilized
to repel flies.
to light
and odors.
Sufficient
additions
of cellulose
material
after
use diminish
or eliminate
Chemical control
should be carefully
considered
and only as a last
odors.
Do not use pesticide
strips
with O,O-dimethyl-2,
2-dichlorovinyl
phosresort.
phate (DDVP) as some conunercia\
compost toilet
manufacturers
suggest.23
This
, and other.controls
are available
which
chemical
is a suspected
carcinogen
are far less tcxic.3s1g
Borax is a good example.
An extremely
small amOunt
(approximately
trm tablespoons)can be sprinkled
on the pile as a fly control
However, borax is toxic
to plants
and will
inhibit
growth if the
measure.
concentration
is too high.
The effective
destruction
of pathogenic
bacteria
may be possible
in compost
toilets
that are constructed
and maintained
properly.’
Pathogens are the
major concern if the end product
is to be recycled.
Equally
important,
however,
is the question
of a virus
destruction
which has not been addressed adequately.
This subject
also is important
when deciding
what to do with the end product
One study involved
the inoculation
of 21 different
models
of a compost toilet.
of composting
toilets
with~Pollovlrus.~*
After four weeks, the survival
rate
had dropped to zero in all of the toilets
tested,
However, the test was
performed
under controlled
conditions
and was designed
to test toilets
used
infrequently
in vacation
homes.
is needed to test virus survival
More. research
in the year-round
use of cmpost
toilets.
Dr. Poorbough in California
has
started
some research
in this area on behalf of EPA. 37
F.
Sumary
This
building
and Recomendations
section
is intended
a compost toilet.
as a guide
for
peop;le
contemplating
using
and/or
1. Familiarize
yourself
with compost toilets
through available
literature.
The bibliography
found in Appendix
B contains
annotations
of publicattons
concerning
compost toilets
or related
topics.
The references
used in writing
this section
also are highly
recommended reading.
You cannot read too much
on the subject
if you are to make an informed decision.
Goodbye to’the
Flush
Toilet
is one of the best complete
sources of information.’
Remember that
-ition
to the whole compost toilet
idea, there are also associated
topics
(e-g.,
coniposting;
greywater)
that youtll
need to read about to understand.
2. Consider whether or not a compost toilet
is feasible
for your particular
needs and living
situation.
Familiarize
yourself
with the concept.
Health
inspectors
are hesitant
to approve campost toilets
and very few states
or local counties
have plumbing
codes which- permit
them.
You will
have to thoroughly
justify
your needs.
Justification
will
entail
convincing
authorities
that you understand
and can solve all potential
problems
involved
in compost toilet
usage.
Remember, too, that a system will
be required
to dispose of or treat
(on site)
all household
greywater.
This
includes
urine,
if you decide on a system with a urine diverter.
The size
of the toilet
holding
tank may present
a problem.
The holding
tanks of the
10
c
slant-bottom
type toilets,
drum privies
and vault
privies
(see Section
II on
design)
all have to be designed
to fit
into basements or into additions
on
existing
buildings.
Be sure to give retrofit
serious
consideration
before
you make a final
decision
on a particular
type of unit.
your wastes will
not be flushed
away and will
be with you until
they are
composted or otherwise
used.
The number of people using the toilet
also
will
be a limiting
factor
- the more people,
the larger
the required
size of
the holding
tank.
Smaller
holding
tanks require
more frequent
emptyings,
especially
if there are large numbers of users.
Consideration
also must be
given to the disposition
of the end product.
There are sani tary requ i rements
for burying
such material
which should be followed
to insure personai
and
pub1 ic health.’
It is inevitable
that at some point,
you will
have to handle feces.
It
is strongly
ret-nded
that you use elbow-length
rubber gloves and a shovel
designed
for handling
waste Mterial.
When you have finished,
be sure to
clean and disinfect
both gloves and shovel for,added
protection,
Additionally,
washed after
you hatie finished
cleaning
your
hands should be thoroughly
equ I pment . Special
precautions
have to be utilized
with composted human
wastes at all stages of the process.
While you and your immediate family
may be relatively
“healthy”
, you may have a guest-user
who is a disease or
virus
carrier.
It is imperative
that users of compost tollets
thoroughly
understand
the health
implications
involved.
While climatic
conditions
can be overcome,
it is important
to realize
that cold indoor temperatures
may affect
your toilet’s
efficiency.
Liquids
aren’t
evaporated
as readily,
the biological
decomposition
process slows
down, and the pile builds
up more rapidly.
Temperature
extremes or other
design problems may necessitate
the use of fans, solar collectors,
heavy
insulation
or other modifications.
3. Experiment
with the compostino
orocess.
To acquaint
the biology
and successful
management of the decomposition
an outdoor
compost pflc using kitchen
scraps,
leaves,
hay,
Experience
in maintaining
a compost
you
the -to ident
=P=- y potential
problems,
and their
solutions
in
yourself
with
process,
try but lding
etc.,
as deflned
in
pile will
enable
your compost tollet.
4.
19 you are thinking
of buildlnq,
carefully
select
and evaluate
the
model you wish to copy.
Read more 1 I terature,
and write
to commercial
compost
toi let representatives.
They will
all have their
usual sales pitches,
but
sag useful
information
can be obtained.
The best sources of information
are others who have built
their
own toilets,
The following
section
on OwnerBuilder
Systems is a good starting
point
for this kind of information.
Be
sure to ask about failures
as well as successes.
Each individual
has probably
modified
a particular
design to suit his/her
needs while solving
specific
problems.
Haybe their
modifications
wil!
work for you.
5.
Bui Id and monitor
.your design.
Make sure your toilet
design meets
basic sanitary
requirements.
Attach permanent usage instructions
in a
conspicuous
place near your toi let.
All guests should be made aware of these
Measure
requirements,
e.g. no plastic,
no cigarette
butts or lighted
matches.
tuaperatures,
odor generation,
insect
populations,
appearance of pile,
potential
11
’
“^__
‘.
‘%.
liquid
build-up
and end-product
appearance,
and record them over a period
of twelve months or until
your totlet
stabtlizes.
This will
give you information upon which to base any needed modifications,
and will
enable you to
determine
ff, In fact,
your toilet
is cormposting properly.
12
II.
OVERVIEW OF COMPOSTTOI LET DESIGN
A.
Introduction
When
field
and
a home, or
built
the
i
beginning
a construction
project,
it’s
always wise to survey the
find out what already
has been done.
Whether it’s
a greenhouse,
a compost toi 1et, there’s
a good chance that someone has a 1 ready
design you’re
hoping to construct,
or at least something
similar.
In Section
II,
the general
design considerations
for compost toilets
are reviewed.
The authors
have established
a set of criteria
to judge the
suitability
of compost toilets,
given the applicable
use, maintenance,
and
health
requirements.
Secondly,
four basic compost toilet
designs are examined
briefly
to orient
the prospective
owner-builder.
Also described
are the
leading
research organizations
and individuals
in the field
of compost toilet
construct
ion.
detailed
information
on determining
the proper size
Fourth*
toilet
(for your use), choosing
and evaluating
building
materials
and
estimating
costs is presented.
The fifth
part identifies
specific
design
problems that must be addressed when building
a compost toilet.
Based on
their
experience
and research; the authors
include
solutions
they formulated
for these problems.
B.
General
Design
Considerations
A composting
toilet
can be built
into an existing
house, as a separate
room, or as a detached privy,
or designed
into a new house.
It can be
installed
in a basement or crawl space, conceivably
even on a lower floor
if the loaded weight
can be supported.
Long cornnode chutes (i .e., a second
floor
cormrode emptying
into a basement instal iation
are not recommended
since updrafts
are 1 ikely to occur.
The toilet
is traditionally
in the same room with the shower/bath
for
convenient
plumbing
hookups.
Water. for handwashing
sbuld
be available
near
a waterless
toilet,
so the traditional
tie is not completely.
severed.
However, it may be desirable
to locate
the privy and a small basin in a
separate
room from the shower.
Such a division
may eliminate
the need for
a second bathroom,
and isolates
the toilet
in case of fan breakdown or
other possible
problems.
Liquid
build-up
has been shown to be ij problem in most owner-built
to design a control
of some sort.
Also,
the
units;
therefore,
be prepared
storage or decomposition
chamber must be waterproof
to prevent
contamination
of surface
and groundwater
supplies.
Ventilation
systems must be screened
to minimize
fly problems.
Air entering
the toilet.
should be 66OF or warmer, so consider
inducing
air from 1) above a stove or furnace;
2) inside
the house; 3) through a
glazed,
south-facing
solar “blackwall
.‘I
It may be helpful
to place the
toilet
on the south side of a house to take advantage of various
solar
heating,
venting,
and insect,
control
techniques.
1.
Desicp
Criteria
There are a number of factors
to consider
in designing
a compost
for a particular
site and use.
The following
checklist
is a designer’s
guide to a well-built
system and can be applied
to all compost toilets.
13
toilet
__-,--
1.
Flying
2.
The container
ch i 1d-proof.
3.
The unit
4.
Convenient
5.
Mass must be sufficiently
air flow of over 66O~.
6.
Room should
7.
Cwrmode and room must be conducive
a.
Toilet
capacity
must be well matched to the household
supply.
unit must accomodate all the wastes of the household as well
wastes of occas ional vi s i tors.
9.
The unit
available
10.
insects
must be controlled.
must be vermin-proof,
must control
emptying
liquid
aerated,
Graphics
clearly
explaining
should be displayed
in the
Basic
1.
Slant-Bottom
Designs
and
the waste
preferably
material
with
is
imperative.
a constant
warm
odors.
must be practical,
materials.
c.
airtight,
buildup.
and hand1 inp of
have no foul
moisture-proof,
to clean
inexpensive,
and sanitary
and built
the use and maintenance
room.
Reviewed
from
of
conditions.
The
as the
locally
the
toilet
.
Desiqn
The best known cormnercial
compost toilet
is the Clivus
Multrum;
this is
the design that is most often emulated
in owner-built
models.
The principle
behind the Clivus
is that a large,
sloping
collection
chamber receives
urine,
feces and other toilet
waste through
the toilet
opening,
and kitchen
wastes
through
a garbage chute (Figure
2.1).
FIGURE 2.1:
SLANT-BOTTOM COMPOSTTOILET DESIGN
The chamber theoretically
receives
intake portal.
Sometimes,
air also is
An initial
bed of
permeate the pi le.
is
straw,
peat mos5, grass clippings,
medim for urine,
as well as to supply
a constant
supply of air through an
diffused
through
an air duct to
soil and cellulose
materials,
e.g.
necessary
to provide
an absorption
organisms
necessary
to decomposition.
14
.
The decomposition
stack.
It takes
up Is a prevalent
gases and evaporated
liquids
are vented
the system at least one year to stabilize,
problem.
The chamber should be emptied
out the exhaust
and liquid
buiidevery 2-4 years.
This design raises a question
regarding
two chutes (toilet
and kitchen).
For the sake of convenience
(kitchen
chute),
the composting
process
is someWastes added in the kitchen
chute may be disproportionate
to
what hindered.
Materials
may not be layered efficlentiy
to
the wastes added at the toilet.
allow proper aeration
and effective
breakdown.
With one chute a more efficient
layering
process
is attained.
Another potential
drawback to the slant-bottom
type design is the huge
Unit size may necessitate
major retrofitting
of one’s basunent or
tank.
the addition
of a special
room).
Also,
the size of the unit
home (i.e.,
directly
affects
the compost ing process.
Note the maintenance
of a large
if the accumulating
mass is not of sufficient
size to retain
the
tank.
generated
heat (given the overall
size of the chamber),
the decomposition
process will
be slowed down and liquid
may not evaporate.
Likewise,
greater
A smaller
unit,
on the other hand, will
gain its
maintenance
is requi red.
mass and retain
its heat more readily,
thereby breaking
down wastes more
rapidly,
but it will
require
more frequent
emptying.
gravity
to
A major advantage of a slant
bottom unit is that it utilizes
simpl ify hand1 ing,’
Raw material
enters at the upper end while the older
composting
matter creeps toward the emptying
door.
Air induced through
the
pile
reduces turning
requirements.
As.you have read, there are strengths
bottom design.
Every owner-builder
should
potent ial problems before construct
ion.
2.
Drum Privy
and weaknesses to the
thoroughly
understand
siantthe
Design
Homesteaders
around the country
have experimented
with container
type privies,
often
using 55 gallon
drums as waste containers.
Advantages
are that waste material
can ‘@age” in one filled
drun without
being contaminated
by more fresh matter,
drums or other available
containers
find a recyclable
use, and the interior
of the prlvy
box does not need to be completely
waterproofed.
There is a wide spectrwn of design possibilities,
but there
are limitations
as well.
This Individual
container
method does not make
efficient
use of space in the privy
chamber as there must be room for
drun hand1 ing, and in storage
there
is lost space between the round drums
as well.
Tom Riley,
drum usage:
P.E.,
an NCAT engineer,stated
1R55-gallon
drms are basically
for use in transports
of 1 iquids.
handling
nor for prolonged
storage
h.is objections
to 550gal ion
large tin cans that-are
They’re
intended
neither
of corrosive
materials.
intended
for rough
“in long-term
storage of corrosive
materials
the most cornnon
failure
is pinholing
or rusting-out
of small leaks.
These will
start
to show up at the end of the second year of storage of water-based
materials.
These often occur either
around the bottom seam where the
metal has been stressed
or at the air/water
interface
around the sides
or top.
Once the first
one has occured,
several
mere.,wi 11 not be far
behind,
so the drum should be considered
to have ended ‘its useful
life when the first
one occurs.
15
.._
s._-___
I._.“_-
FIGU.RE 2.2:
DRUM PRIVY
: often coated with various
materials
on the inside
Ihole rusting.
The interior
coating
of a drum, howto do. There is a deep seam around the bottom and top,
ly filled,
as the coatings
tend to shrink
as they dry
MII the interior
cracks.
And, as air circulation
in
zd, it is difficult
to get the seams to dry properly.
I add several
years to the life
of the drum, but should
dependable
beyond that.
The drums can be “hot dipped
rmpiete heavy plastic
liners
can be installed,
but
tdd so much to the cost of the drum that they are no
;ive container.
16
‘IA second consideration
is the mechanical
handling,
a 559gallon
drum
full
of water weighs approximately
480 pounds.
A fui I drum is then
very difficult
to handle by hand, and if mechanical
aids are used, the
druns are easily
damaged.
The drums can often be damaged simply by
letting
them fail
over on their
side.
Once a drum has been bent or
beat up, the seals for the lid and bung holes should not be considered
dependable,
and once rust has started,
the metal of the drum is
severiy
weakened and mechanical
damage becomes ail the more likely.
*@The drums also are not intended
for high pressure;
in fact they are
If a sealed drum is heated and cooled
rated at 8 pounds per square inch.
during
the thermal
cycling
process several
times,
leaks from the canning
at the top and bottom of the drum are highly
1 ikeiy.“27
With due regard for Riley’s
position,
drum privies
may provide
sanitary
toilet
facilities,
and experimentation
has been done with the technology.
An excellent
report
of drun privies
has been published
by the California
Prospective
builders
interested
in this
Off ice of Appropriate
Technology.
design should obtain
and read the paper entitied,“Finai
Report Phase I of
Rural Waste Water Disposal
Aiternatives”(wri
te OAT, P.O. Box 1677, Sacramento
California
95808).
3.
Vault
Privies
A vault
privy
is a double chambered box and generally
consists
of two
vaults.
or the material
from one
The seats are moved after
one is filled
vault
is moved to the other for composting.
The unit
is simi iar to an outhouse
except that the waste storage
chamber is designed
for accessibility
to
It is recommended that the end product
is allowed
to stabfacilitate
turning.
it ize for 6-12 months before hand1 inD.
FIGURE 2.3:
DOUBLE CHAMBEREDBOX OR VAULT PRIVY
17
The double (or multi) chambered box privy
is the simplest
system; one
chamber is filled
for usually
six months, then the pile
(or in some designs,
the co-de)
is moved and the other chamber used.
Pile should be turned
once or twice a month.
Such regular
pitchfork
turning
allows
for effective
compost ing . However, sanitary
precautions
must be taken to insure that
a health
hazard isn’t
created.
Use of rubber gloves,
sterii
izing equipment,
and hand washing
is recommended.
Additional
iy, it is questionable
as to how
many awner-builders
will
be willing
to turn the pile on a regular
basis.
Also, without
urine separation
or drainage,
there will
be a liquid
bui idup.
The Faraliones
Institute
has tried
to solve these problems by
co1 iect ing urine separately,
recommending use of 100 pounds of dry material
(straw,
peatmoss,
sawdust)
during each month, and advising
people as to
the turning
procedure.
According
to Farai lones researchers,
separately
collected
urine can be siphoned off and used in a diluted
form on an outdoor compost pile,
as well as on house and ornamental
plants.
However, the
safety of using the liquid
for such purposes has not been proven.
This system provides
an excellent
educational
opportunity
for observing
the decomposition
process and allows one to invite
potential
converts
in
to watch the turning
process.
It also provides
them with an opportunity
to
witness
malfuncti:ons
or problems
(if any) which makes the educational
(See Cal i fornia
OAT report
for more detai 1s) .
experience
real ist ic.
4.
Appliance-Type
Designs
Small appliance-type
composting
toilets
use induced heat to raise
pile temperature
for speedier
decomposi t ion.
Such above-f ioor uni ts can be
easily
installed
in most existing
bathrooms.
Disadvantages:
their
electricity
consumption
is about the same as a refrigerator;
they can serve
only one to three people full
time;
they are susceptible
to caking and
hardening
of the m&s near the heater;
explosive
fruitfly
populations
are
prevalent;
and, (in some types)
there is 1 iquid pooling.
They have a more
delicate
balance point than the larger
units and need more sophisticated
care.
There is practical
application
of the units
in specific
situations,
as well as solutions
to most of the problems;
but, the average family
(or
individual)
generally
requires
a unit that
needs
less maintenance.
Also, the appliance-type
design is least likely
to be constructed/duplicated
by an awner-builder.
These small electric
compost toilets
are intended only
for use in seasonal
buildings
where they receive
very controlled
and intermf ttent
use.
They are not recommended for year-round
homes.
18
FIGURE 2.4:
5.
Design
APPLIANCE-TYPE DESIGN
Research
Since so little
information
exists
on awner-built
compost toilet
designs
any experience
in using an owner-built
design can be considered
research.
This section
highlights
the efforts
of a few individuals
and groups who are
noted for their
work in compost toilet
research.
The Clivus
Hultrun
compost toilet
is the subject
of a number of research
papers concerning
the stack gases emitted
and the analysis
of the bacteriai
However, each of the
and chemical
composition
of the end product. 28* 2g*so
in the papers
studies
only Involved
a limited
nrrnber of toilets
(2-g units),
concerning
chemical
and bacterial
analysis,
seven of the toilets
were
instal lat ions in Sweden. 2es2g
Since Sweden Is the birthplace
of the original
Clivus
Multrun,
it is probably
true that the toliet
owners there were quite
familiar
with the use and maintenance
of such a toilet,
and therefore,
the
3 While the results
are informative,
positive
results
may be misleading.
they cannot be relied
on as being the final
proof of compost toilet
safety.
The Faraiiones
institute
in California
has researched
compost toilets
Their work in compost toilets
primarliy
and greyvrater
recyci ing. 3* ”
involves
research
with vault-privy
and drum privy
designs utilizing
a
Compost
toilets
and
greywater
systems
can
be
observed
31
unit.
pusteutlzt;ng
there. 32
The California
Office
of Appropriate
Technology
Phase I Report of Rural
Waste Water Disposal
Alternatives
stated
research
needs for dry toi lets and
Phase ii will
proceed with funding
from
greywater
systems for that state.6
EPA to develop design guidelines,
a user-education
program and a health
and
19
building
officials
approval
rogram for non-conventional
toilets,
and health
risk evaluation
data, l6 33
The project
wii 1 analyze
36 dry toilets
and
12 greywater
systems.
Completion
of the Phase I I in about one year w i 11
result
in a publication
from EPA. (Contact
Steve Hathaway, Project
Officer,
Systems Engineering
and Evaluations
Branch, Wastewater
Research Division,
EPAs Cincinnati,
Ohio, 45268, for information.)
The final
Work Plan for
Phase II can be obtained
from the Office
of Appropriate
Technology,
1530
g58\4.33
10th Street,
Sacramento,
California,
The
The State of Oregon al lows experimental
use of compost toi lets.
Department
of Environmental
Quality’s
On-Site
Systems Program asked peryit
holders
to fill
out questionnaires
concerning
the use of their
toilets.
with compost toilets.
The descriptive
survey generally
identified
the problems
nPst owners installed
slant-bottom
type toilets,
and almost all experienced
problems with explosive
fly population
during ecosystem stabi! ization.
Hany Owners also experienced
problems with liquid
buildup.
One owner instal led
This system proved tie be the most
a drum privy and reported
few problems.
The
efficient
in terms of cost and maintenance
of ail systems surveyed.
Oregon study indicated
that comnercialiy
available
models have the same general
For more information
on this survey write
prohluss
as do mar-built
urits.
to the Department
of Environmental
Qua1 ity,
State of Oregon, P.O. Box 1760,
Portland,
Oregon, 97207.
The San Dicmas Equipment
Development
Center performs
research
for the
compost toilet
design for back-country
are being used are commarclai
models.
Research with these units
concerns
the reduction
of mass.
Core samples,
volatile
solids
and decomposed mass versus fresh feces will
be tested
in
California
and Appalachia
Forest Service
areas, and the results
will
be
pub1 ished around the fall s 1979.
Their work includes
Forest 3tervice.
The compost toilets
that
usage.
In Halne, Alexander
*2andyk1 Clark has been involved
with compost toi lets
several
years and has some unique and ingenious
ideas in their
design,
particularly
for use on “the rocky and romantic Maine coast.“”
Maine,
because of its hlgh water table,
has recognized
the use of compost toilets
In its plunhing cqde. The major problems with compost toilets
identified
in
Clayk*s
research’ are excessive
1 iquid buildup
from too much urine and too
1 ittld’evaporat
ion, ‘O ”
Clark’s
solution
is a urinal,
made from a cut-out
bleach bottle
and hoses and attached
to the front
of the inside of the compost
td 1et (see Si t-Down John 1n Sect ion I I I ) . This requl res everyone to sit
while urinating.
The urine
is then treated
separately.
Af!er being in the
Clark strongly
recommends that any
cammcial
campost toilet
business,
serious
owner-bui ider seek “Intel
1 igent,
unbiased
consul tat ion” in choosing a
ties ign. 3c For’more
information
on the urine diverter,
write
to Clark (and
revised
his compost
read about his system in Section
11.1). Clark has recently
toglet
booklet,
Cheap Tricks
for North Country Compost Toilets.
Wastewater
(1979).
Recycl inq and Methane Digesters.
for
0.
Construct
ion Parameters
Proper sizing
of unit eliminates
overloading
the system and insures more
ef f i clent operat ion.
One way to determine
a size estimate
for an owner-built
A more
system is to compare and average the sizes of commercial
models.
technical
method involves
must be able to handle.
estimating
the volume of wastes
Consider
this approximate
sizing
that the toilet
process:
DAILY TOILET USAGE*
3 pound of
I quart of
Plus:
Note:
feces
urine
One scoop
each use;
per person
per person
“dry flush”
mix
kitchen
garbage,
For five people,
the
reduce to .75 pounds
(peat moss, sawdust,
straw)
for
toilet
paper, sarliiary
napkins,
24 por;ndgof
dry.
feces
per day will
etc.
eventually
The mass in the unit will
not reach this dry weight and volume at the same
time since there is continuous
input of fresh material.
At the end of the year,
30 percent of the feces averages wet, and half of the urine solids
will
have
drained
off.
if the unit
is to be used without
emptying
for 14-2 years,
there
must be two cubic yards or more of usable volume.
Farallones
uses larger
quantities
of sawdust/straw
than is suggested
here, the main purpose being to raise the ratio of carbon to nitrogen.
Use
of larger
quantities
of sawdust/straw
also serves to absorb excessive
liquid.
If less nitrogen-rich
urine enters and evaporates
in the chamber, there will
be a reduction
in the nitrogen
content,
making it possible
to cut down the
amount *of added carbonous
material.
*Note:
Many of these base figures
Privy,”
‘The Faral lones lnst i tute,
Cal ifomia,
95465.
2.
Bul Idinq
are from “Technical
Bulletin
#l, Composting
15290 Coleman Valley
Road, Occidental,
Materials
Cinderblock,
cast concrete,
treated
plywood,
fiberglass,
and ferro-cement
have all been used by innovators
in construction
of composting
toilets.
A .
wood-frame
ferro-cement
structure
also is a suitable
building
material
for
several
reasons:
1) the box can be we1 1 insulated
for a winter
cl imate by
using 6-inch
studs and R-19 fiberglass
(to help the pile hold heat);
2)
ferro-cement
has a certain
amount of elasticity
making the interior
somewhat crack-resistant;
3) the medium is easily
shaped to a minimum 6 inch
radius of curvature
on lawer edges to prevent
freeze damage to the box;
ferro-cement
on wood frame medium allows
for great design freedom and Innovat ion.
All sorts of shapes, sizes , and effects
are easily
achieved.
However, the construction
of a wood-frame
unit can present
problems.
Beware of heavy, rough-cut
lumber, as the resulting
box can be too huge and
heavy to move into place.
Often there is not enough space to assemble the
stu&ralls
and position’the
box, and cement blocks might then be more
If the unit
is to
practical
since they are raised
into place one at a time.
be partially
buried,
consider
investing
in pressure-treated
framing and plywood.
Working with rough-cut
lumber is generally
half the cost of planed,yet
it
Be
sure
when
using
rough-cut
can take twice the time and be: frustrating,
2x6’s and 2x4’s that the lumber is not green, as it may shrink
and cause
cracking
of the cemnt
interior.
Be sure the lumber is of even widths.
Unless you are experienced
with rough Lumber, and/or have an open and accessible work area, it is advisable
to use planed 2x6’s.
Remember that it will
be
inconvenient
to go inside
the unit after
it is in service
if the cement
appropriate
materials
and build
cracks.
Do it right
the first
time . ..choose
on a foundation
that will
support
the weight of the filled
container.
21
3.
cost
Costof-rcially
made composting
toilets
sized for full-time
family
use ranges between $850 and $2500 for the unit and installation.
The sitebuilt
system (similar
to the one outlined
in Appendix
A) costs approximately
$450 for materials
plus $500 for labor.
By bui iding yourself
or having
a knowledgeable
contractor
build
for you, cost f lgures are cut roughly
in
Furthermore,
the money is recirculated
closer
to home. Presently,
ha1 f.
caamnercial units
have hlgh initial
factory
and advertising
costs;
prices
thou1 d decrease whenever demand rises
to a supportive
level.
There is a second cost to consider:
the additional
expense of installing
soma sort of treatment
system for shower, sink and washwater.
This “greywater”
also contains
pathogenic
organisms
and needs treatment.
Cost of an effective
greywater
recycling
or disposal
system will
usually
run between $400 and
$1000.
However, one advantage of using a compost toilet
is that it allows
for the use of a reduced size greywater
disposal
system.
E.
Design
1.
Criterion:
Problems
and Solutions
Flying
insects
must be controlled.
Infestation
by germcarrying
flies
has been a major problem of compostlng
toi lets.
One way the insects
enter the composting
chamber is in the larvae
stage on wet grass clippings
or in wet straw that is added to the toilet
mass.
Fl ies are .not harmful
in the tot let.
However, they do cause trouble
when they
1eBve the compost.
Attracted
by the 1 lght above the seat, the flies
carry
bacteria
into the roam.
Al 1 interior
surfaces
of the tot let should be black.
The chute and underas this coloring
limits
reflection
side of the commode lid should be black,
of light.
Since most flying
insects
are drawn to light,
the next step is to
attract
tham into a srnsll container
from which they cannot escape.
A %olar”
Bye-Bye Fly Trap can be mounted high on the side or on the top of the unit;
daylight
shines
in through
glass and reflects
on the white painted
surfaces
of the trap‘s
small box (see construction
details
of fly trap in Appendix A).
The flies,
attracted
by the reflected
light,
easily
enter through a funneled
Inside the air tight
chamber, fl Ies are killed
by chemical
pest
opening.
strfp
or can be captured
on flypaper.
Fruit
files
are least apt to enter the
Bye-Bye Fly Trap; house flies
can be 99 percent
controlled.
The trap (for
large vol une, owner-bui 1t unt ts -- see drawings
for construct
Ion and detei is)
is east iy serviced
and is remvabl e so the pi le can be observed and raked
through
the Wsquare
opening.
If sufficient
direct
or indirect
sunlight
is
not available,
a %ightlighP
or is-watt
bulb can be secured on the glass.
As manufacturers
and owner-builders
further
develop and employ this national
“bug to the 1 ig ht” technique,
composting
toilets
wi 11 be safer.
As nmntioned
previously,
borax
applied
directly
to the pile has ibeen used
However, the chemical
is toxic
as an effective
chemical
against
fly larvae.
to plants
and could render the composted end product
useless or even harmful
The addit ion of 1 ime and woodash
to soil.
It s)Puld be used sparingly.
(with no clinkers
or sparks,
which increase
the fire
hazard) will
control
An excellent
and easily
read article
flies
and produce no negative
effects.
on fly controi
and the fly’s
life--c
cle is the USDA’s publication
on ‘The
House Fly and How to Suppress I t.‘l2 li
22
One homesteader
in West Virginia
painted
the inside of his hullbank
(a smail appliance
type) toilet
with a special
flat
black paint
(he used heatresistant
charcoal-grill
paint which adheres well to the polystyrene,
once the
surface
is sanded).
Using a drill
and a saber saw, he cut a 2f-inch
diameter
hole in the upper right
side of the back of his unit,
He sanded the surface
and, using Eastman 910 adhesive,
cemented on a 3 inch jar lid with a correspondind hole cut from 1ts center.
After
the glue dried,
a 5 inch long olive
jar,
containing
& of a pest strip,
was screwed onto its lid now on the side of the
Hul lbank.
Fruitflies
have to date
been the only pests, and have been kept
in check by this simple Jar trap.
tlanufacturers
of camnercial
toilets
recommend various
insecticides
or
customariiy
suggest placing
a chemical
pest strip
inside
the unit.
We are not
sure about possible
damage to the compost or to helpful
organisms
from such
a caitrol
technique.
Some insecticides
used in pest strips
are suspected
carcinogens
. Nonetheless,
control
is more regulated
and effective
with pest
strips
since mst of the poison no longer goes directly
up and out the vent
stack,
and risk of contaminating
the pile with the poison is almost eliminated.
General Notes:
It is still
vital
that all
incoming and outgoing
airvents
are screened,
and that kitchen
garbage is well covered until
placed in the
to1 let.
Handle pest strips
with rubber gloves.
Spiders
can prevent
flies
from entering
a bug trap by spinning
webs across the trap opening,
so be sure
to clean old webs from trap entrances.
Spiders
are, however, an efficient
fly
and their
presence should be encouraged.
2,
Criterion:
Unit
should
be free
from
liquid
buildup
I
control
problems
Without
auxilary
heat, composting
toilets
cannot evaporate
the total
urine
input.
Excess 1 iquid pools at the bottom of the unit,
a common occurence
with
Clivus
Wultrum, Toa Throne,
Faral lones Box Privy, .and others.
Manufacturers
often claim their
units will
evaporate
liquid
if incoming air temperatures
In practice,
this
remain
above 66OF and sufficient
dry material
is added.
tmrature
condition
can be hard to achieve.
What is the advantage
of a %losed”
or %ontai ned” system over ‘an l’open”
one which will
drain?
it is easier
to install,
and may be applicable
to more
situations
since there
is no effluent.
In working
situations,
we have seen
too few closed systems performing
satisfactorily.
An open system can eliminate
1 iquid but ldup worries.
A drain
is placed at the lowest point of the toilet’s
chamber floor.
Use
a bell-type
basement drain,
a rooftop
drain,
or a shower drain and treat with
epoxy or resin.
The drain must be accessible
for cleaning.
Cover with gravel
contained
by a l-inch
high circle
of galvanized
and epoxied diamond mesh. Cap
with straw.
drain
Liquid,
through
instead
of pooling
a 2 or Pinch
lin:
st
the bottom
Into:
of the
unit,
will
automatically
reduced-size
septic
tank and leach
A. a health
department-approved,
field
2 gallons
per minute aerated
With water saving hardware
(e.g.,
&&-heads,
saver sink aerators),
a 500 or 750-gallon
tank coupled with
half the standard
leach field
should do the job and (might)
meet approval.
Effluent
from the toilet
and urinal
with five users amounts to no more than
300 gallons
a year (80 gallons
per person,
less evaporation).
Also,
it is
23
I
quite possible
that the nitrogen-rich
toilet
of greywater
(a subject
worthy of research).
B.
connected
trench.
suited
to
effluent
will
aid
in
breakdown
a treated,
buried,
55-gallon
drum (serving
as a mini septic
tank)
to a minimum IO-foot
length of leach line set in a standard
gravel
This method takes toilet
and urinal
effluent
only,
and may be well
a free-standing
privy when leach field
area is available.
a 20-55 gallon
holding
tank.
c.
Use shower drain;
vent holding
tank
back
into
the
toilet
with
a
straight
2
inch
pipe.
The
tank
can
be
equipped
_
& .
with a marine hand operator
bilge
pump, or if desired,
an electric
sump pump
(can be automatic
with ball-cock).
Tank should have a float
or window
gauge, and an access panel so that any solids
building
up could
eventually
be
removed.
A butterfly
valve in the 1:ne could send effluent
recirculating
over
dry edges of the pile for another
chance at absorption
and evaporation,
or
into a leach field,
or to the serious
recycler’s
hose and bailing
bucket
(dilute
with water and use as a non-edible
plant and shrub fertil
izer
Remember, the safety
of such.use
has not been proven).
FIGURE 2.5:
SUGGESTEDDRAIN SYSTEM
24
9.
informat
a greywater
ion).
recycl
ing f i 1ter
system
(see other
sources
for
specific
Some experimenters
have used diverters
to separate
urine by placing
a
screened funnel or auxil iary container
inside
the front
of the cornnode.
Our trials
resulted
in toilet
paper clog-ups.
The bases for urine separation
Liquid pooling
and cooling
problems are lessened,
and less nitrogen
is
are:
To lessen maintenance,
it is probably
easiest
to build
in
put to the pile.
a drain and install
a separate
urinal
rather
than the diverter.
The pile
can be kept damp, not wet, and concern for urine buildup
will
be reduced.
A practical
urinal
can be made
similiar
plastic
or metal mechanic’s
a wooden mount.
A half-cup
of water
Plumb into existing
greywater
system,
urinal
also eliminates
splashes
and
3.
material
Criteria:
Convenient
are imperative.
from a Hollywood
Accessories
brand or
funnel,
and built
so that 1t closes on
can be poured in after
use to 1 imit odor.
toilet
drain system or holding
tank.
The
drips on the seat from the male users.
emptyinq
and minimal
handling
of the waste
Slant-bottom
designs
use gravity
to move the pile;
older material
is
from the bottom,
away from the raw material
that enters
from above.
Hore efficient
composting
will
take place with some sort of hand or mechanical
stirring,
so we suggest this nrrnthiy
procedure.
emptied
Uear elbow length
rubber gloves.
Poke pile with a stick
or hoe from
cornno& opening,
topple and mix the “cone”.
Add add1 tional
“dry flush”
or straw to give pile a looser consistency.
Mixing should also be
performed
through
the fly trap/access
port,
but only expose one opening
at a time so odor does not draw into room.
Clean gloves and hands
immediately
afterwards
with disinfectant
soap and water, or with alcohol.
The stick
can then be buried,
placed in a plastic
bag for disposal,
or stored
inside
emptying
hatch for future
use.
This mixing operat ion
should take about 15 minutes.
A properly
sized,
slant-bottom
unit should need emptying after
the first
ii-2
years, and regularly
every 3 months thereafter.
Current National
Sanitatfon Foundation
standards
require
afterburial
of the end product
for varying
lengths
of time corresponding
to the length of time the substance was in the
container.
Plan on afterburial
for l-2 years under at least 6 inches of
topsoi 1. The FaraIlonas
Institute
uses screened,
wooden composting
bins for
their continued
cornposting,
and they find further
significant
reductions
In
vol woe.
Plans for construction
of such bins are sold by the Institute.
4. Criteria:
Mass must be sufficientlv
aerated.
preferably
with
constant
warm air flow of over 66oF.
Room should have no foul odors.
AddItlonalTy,
potential
fire
problems must be considered
and corrected.
a
Compost piles
bre usually
aerated by a person with a pitchfork.
Compost
toilet
designers
attempt to eliminate
this person’s
job with designs that
continually
induce air under and through
the pile.
There are three basics to
such a ventilation
system:
1) a source of warm incoming air,2)
a means of
inducing
the air,
and 3) a means of exhausting
the air.
install
floor
An effective
way for inducing
warm air in the wintertime
would
the unit
in a plenum crawl space, where the periphery
rather
of the house is insulated
and warm air is tlown down from the
25
be to
than the
ceiling
-_
into the crawl space.
There air is forced
into the rooms through open floor
registers,
achieving
central
heating
without
duct work.
Draw from the toilet’s
smai 1 fan would pull a port ion of the warm ai r.
However, this is an untested
i&d.
Since we do not usually
have the opportunity
to design into such an
integrated
system,
the best approach for most installations
is to pipe air
directly
into the unit from a warm high place in the house.
Use four- or
six-inch
WC pipe and insulate
as it passes through
any unheated areas.
Bends
of 450rather
than 9pare
best to decrease resistance.
It may be desirable
to
draw slmnertime
air directly
from the outside:
remember that the screening
takes away half an opening’s
space; design intakes
and exhausts
to make use of
the size of the pipe.
Air is rmst comnoniy ducted through
slant-bottom
units by using inverted
‘3’ shaped or slit-open
PVC thickwall
pipes.
Be sure pipes are strong
enough to hold up under the weight.
Perforated
pipes are not recommended
because the holes may clog,
The use of pipes he1 ps keep the pi 1e from compacting, but can complicate
pile turning
and efficient
operation
of the bottom of
Remember that pipes should not inhibit
downward flow of the pile,
the pile.
ad ttiy
sbuid
run parallel
to the slope.
The most
by Max Kroshel
Department of
air system is
bottan of the
urf t draws air
across the top
efficient
aeration
system to date may be one recently
built
at the Farallones
institute,
working
under a grant from the
Energy’s
Small Grants in Appropriate
Technology
program.
His
similiar
to the Toa Throne in that
air passes through
the
Max’s
pile by means of %tairsteps”
that incl ine downward.
from the main chamber down through
the steps on warm days and
of the piie on cold days and nights.
The stairsteps
increase
hanets
for aerobic unnposting to take place in the entire
pile,
and set
similar
conditions
for any manual or mechanical
raking and turning.
The
steps are inclined
downward so that no material
enters
the open chamber
lndemeath
and are spaced several
inches apart so that a sort of tumbling
action
takes place as the pile slides.
Air
is exhausted
most reliably
through
use of a small,
continually
If natural
draft
long-life
fan mounted in a six-inch
vent stack.
must be used, careful ly research options.
A San Diemas Equipment Development
Cent& (SDEDC) study shows a 16 inch wtnd turbine
placed over the roof vent to
be slightly
less efficient
than use of a two-foot
extension
over the vent.
Hex Kroshei’s
stairstep
privy
uses nstural
draft
drawn out of the unit by
@W&IS of a thermosiphoning
solar chimney, which opens and shuts aut
Natural
draft
becomes complicated
be
with use of bi-mtai
dampers.
Lareful
charge in day/night,
sunnner/winter
temperatures,
and wind factors.
planning,
with consideration
for venturi
effect
is necessary
in vent design.
Refer to the SDEDC study for further
information.
operated,
Another potential
problem of composting
toilets
is the possibility
of
inside
the toilet
chamber (instead
of water we Westerners
have become
accustomed to) there is some dry toilet
paper and air flow, so a cigarette,
hot rrood ashes, etc. could start
a damaging fire.
Users should be made aware
of this danger.
fire.
26
With a good &sign
there is almost no possibility
of methane buildup
and
subsequent
fire,as
airflow
keeps any gases from collecting.
However, if poor
design causes air flow to be inhibited,
gas will
accumulate
and create a fire
Heating elements
positioned
too close to dry toilet
paper or flammable
hazard.
cmptments
also will
cause fire.
Faulty
design rather
than mis-usa
is the
chief
cause of fire.
Toilets
can be equipped with thermostatically
oontrolled
extinguishers,
sprinkler
systems, or heat alarms.
Such equipment should not be necessary
hound installations
where users become accustomed to the systems.
27
in
_.
.“__
,’ -
111.
SELECTED OUNER-BUILT SYSTEMS
A.
I NTRODUCTI ON
Once you are sold on the idea of owning a compost toilet,
you must decide whether to build or buy the system you prefer.
There are advantages
to either
choice.
If you build,
you will
spend less money, be able to use
local materials,
and take pride
in having built
your own system.
What’s
mre,
you can tailor
your toilet
system to meet the specific
needs of your
On the other hand, buying a “ready-made”
faml ly.
system is practical
for
different
reasons.
Primarily,
you don’t have to invest
the considerable
time and energy involved
in toilet
construction.
Building
and installing
can be difficult
and frustrating.
Usually,
those persons who opt to buy
recognize
this time cunmitment,
and prefer
to spend the additional
money
for a comercial
system.
In this section,
the authors
describe
units which can be owner-built
and installed.
A couple of the units are convnercial ly produced,
prefabricated
models for home installation.
Other designs are personal lred
copies of cormserciaily
built
compost toilets.
At the end of each review
is a stumeary of apparent
good and bad points
for each of the destgns.
We
will
leave it to the reader to determine
which is best for his or her needs.
Should the reader be interested
in a particular
model, it is recommended
that the designer
of the unit be contacted,
extensive
reading be done on
the subject,
and visits
be made to sites where the unit
Is in use, if at
al 1 possible.
It is also advisable
to investigate
local plumbing,
health
and building
codes to insure that construction,
installation
and use are
permissible.
We have provided
this survey of owner-built
models to indicate
what
people are doing in human waste management.
System costs ranged from
*‘for free”
(using
recyclable
materials,
free for the time and labor expended in collection)
to about $1600.
Most of the units were designed
for
year-round
homts, but the number of persons each type of toilet
can accomdatevaried
with each design.
Haintanance and start-up
requirements,
frequency in handilng
raw materials,
and uses of and products
wlll
be dtscussed for each model.
it is recommended that the reader contact
the designer/builder
ing retrofit
requirements,
greywater
and other types of backup
report
on gremter
systems is forthcoming
from NCAT.
regardsystems.
A
We sent out questionnaires
as we received
leads on owner-built
units.
However, very few responses were received
by our deadline
date.
It should
be noted that mst of the responses received were from the east coast and
mst of these were from the New England or upper mid-Atlantic
states.
(This
is not to say that there is nothing
being done in other geographical
regions,
only that responses were primarily
from the northeast.)
We hope to update
this handbook within
the next year; by that time there should be more ownerbuilders
to supply
input with improved information.
An outdoor
toilet
(the Bin Composter)
and klorks in conjunction
with an outhouse,
28
which requires
regular
maintenance
has been included.
This design
is for those who live
in an area where
tricity
isn’t
feasible,
but who would
soon, rather
than sealing
up the privy
tensive
period of time.
This type of
at backcountry
campsites.
This system
to home usage, especially
if there are
to use it.
outhouses
are acceptable
and eleclfke to use the end product
relatively
and letting
it decompose over an exsystem was initially
designed
for use
possibly
could be applied
in principle
large numbers of people in the family
TW written
descriptions
(no diagrams or drawings
submitted)
of original
design,
owner-built
models were received.
One strongly
resembles the Clivus
Host of the models cited
in this report
are owner-built,
but are
Hul trum.
copies of ccnmnercially
available
systems.
The other unit,
which was completely
owner-built
and designed,
is for use
in a year-round
home and is made completely
from recycled
materials
(plywood,
plastic
and any other scrap materials
that could be had for the hauling).
The unit can accamnodate up to six adults,
year-round.
It is relatively
maintenance free (yearly
cleaning
out; knocking
down the pile once every three
months).
if fJies
pose a problem,
flypaper
strips
are hung and layers of
peat moss are added after
turning.
This particular
system also includes
a
built-in
drainage
system (similar
to the urine diverter
designed by Zandy
Clark),
which cuts down on maintenance
problems.
The owner-builder
does
not use straw in his compost toilet
because, when combined with urine,
it
attracts
flies.
The owner is very satisfied
with the prototype.
(For mOre
information
on this system, write
to:
Shabatt,
P.O. Box 294, Beacon, NY, 12508).
One camaarcial
unit,
the Bio-Recycler,
is described
in this section.
It
has baan included
because it takes the concept of composting
toilets
and carries it farther
than any of the other units descrtbed.
The Bio-Recycler
aerates
organic
matertal,
effectively
disposes
of urine runoff,
has no insect
or odor’problems
and uses earthworms.
These features
will
be discussed
in
greater
detail
in the section
on the Bio-Recycler.
We did not cover the smeller
electrical
units
because our primary
focus
on units which can be built
by the typical
homeowner with typical
handyman skills.
The reader should keep in mind that discussion
of a particular
type of toilet
does not mean endorsement
by NCAT.
was
AS a final
note, those parsons Involved
with compostfng
toilets
are to
ba cclanranded for their
efforts
in human +++ssta management.
We hope that thls
han’ba&ook will
prove helpful
to those who K
.tish to put an end to the five gallon
l
B.YOOB-FRAHE COHPOSTING TOiLET
The @-franre
ing a ferro-cement
at about $500 for
Informat
ion :
composting
toilet
has a slant-bottom
shell
(see drawings)
and installation
materials
plus $500 for labor.
Jon Aver I 11
Box 40, Brooks Route
Hinton,
WV 25951
mod frame supportcosts are estimated
Four full-time
users plus occasional
visitors
can be accommodated by this
The woodunit which can be installed
in a basement or attached
to a house.
frame composting
toilet
also can be a free standing
unit.
Maintenance
requirements for urine control
involve
malntalning
air temperatures
at 66O~ or warmer
and adding sufficient
dry materials.
A drain to suitable
disposal
field
is
highly
recormuended,
29
,/
/
Control
of insect problems
is attained
with a “Bye-Bye Fly Trap” (93 percent effective
for house flies)
which keeps fruit
flies
in check.
Screens
on incoming and outgoing
air vents are also recommended, as well as painting
the outside
of the toilet
black to limit
light
reflection.
Handling
of raw materials
is reconmnended to wear elbow
hands after
mixing compost.
requires
approximately
15 minutes monthly.
length rubber
gloves and to sterilize
gloves
It
and
This system is reasonably
priced,
but the unit and its air system are
somewhat complicated
to build.
This toilet
is designed with a Clivus-type
sloped bottom, as this slant-bottom
is most effective
for allowing
aged
materials
to creep forward out of the way of newer materials
with minimal
poking at the pile.
This is important
for those persons who need to use
compost toilets
(bet‘P, of terrain,
lack of water,
high water table,
etc.),
but who are not net
”
Dl&;lsed with the idea of working with composted
materials,
except a~
$!,I praduct .
In Appendix A, Averill
details
- the sqod-frame composting
toilet,
including
his construction
prcitduuL!.
the fly-trap
mechanism.
C. SIT-DOWN JOHN
This
exception
concrete
lnformat
ion:
Zandy Clark
Star Route #3
Bath, Maine
04530
model is similar
to other Clivus-type
slant
bottom units with the
of the urine dlverter
feature.
The Sit-Down John is a wood and
angle box.
Urine diversion
allows
the chamber to be unheated,
or even frozen,
in
winter,
reducing
the house heat load and complexity
of design.
The chamber
can be very snvali , since little
cellulose
material
needs to be added.
Also,
the whole system can be cheaper and can serve an unlimited
number of people
without
overloading.
Urine diversion
recycles
nitrogen
better
than aerobic
composting,
because it remains liquid
and does not evaporate
as ammonia.
Installation
costs for this toilet
range from approximately
$270 fc.r
materials
only,
lamerto an estimated
$850 with labor.
Lag bolts,
faucsl
gency draining),
cinder
blocks for walls,
standard
steel cellar
wirl,*,w
casing, standard
vent fitting,
brackets,
f/4” galvanized
water pipe or 2” ’
wood resin for caulking,
6.F. Goodrich caulk,
PL-200 Rubber Sealant
hesive or sfllcone
caulk are inciuded
in the materials
necessary
fca VI9
structlon.
The Unit accommodates ten or more persons.
The number of people a unit
can accormnodate depends largely
upon good aeration,
maintaining
air intake
I t is recommended
temperature
of 65OF and diverting
urine from the pile.
that four to five people use the unit if urine
is not diverted.
Emptying
one or two Buckets of compost yearly,
cleaning
dust from intakes
(which is
mosquito
netting),
and ad-ding peat moss or grass c-lippings
to the toilet
twice a year are required
maintenance.
Start-up
requirements
for this system are the same as for others,
eluding
cover grid with hay or damp newspaper,
addition
of manure, etc
get started
(20 cubic feet to start),
three bales of wet peat moss wil
The end product
can be used on lawns, ornamental
plants
and shrubs,
or
ed to new toilet
compost.
in.; to
1 work.
add-
,
FIGURE 3.2
32
____I,.....-~^sl__
FIGURE 3.3
33
Clark founded the Alternative
Waste Treatment
Association
and published
it is recommended to contact
Zandy
the Compost Toilet
News until
recently.
Ha is well informed on compost
for materials
and systems speci f icat ions.
toilets
and is m&willing
to share his knowledge with others.
It is worth reiterating
that the urine diverter
keeps the pile drier,
Use of urine
allowing
operation
in colder
buildings
and use by mOre people.
to some men.
diverters
requires
that men be seated , which may be distasteful
Warnen, however, wi 11 appreciate
the dry seat.
The amount of beverages consumed by the
alcoholic
and caffinated
beverages make for
can’t evaporate,
the pile becomes too wet,
urine separation
makes heavy drinkers
less
that compost toilets
without
urine diverters
are severely
1 imited.
IL THE MAINE TANK
The Haine
prefabricated
Materials
cost
materials
such
For example,
users is critical.
If this moisture
more urine.
Again,
cools and turns anaerobic.
Zandy’s convinced
bothersome.
or some type of drain mechanism
lnformt
ion:
Peggy
Maine
Deer
(207)
Hughes
Compost
Isle,
ME 04627
348-6687
Tank (poured-in-place
concrete
tank)
1s smaller
than
unit on the market and costs less than $900, excluding
under $500 (1978),
which can be reduced by recycling
as sheet matai,
existing
chimneys for venting,
etc.
any
labor.
some
The unit accamnodatas
three pcopls with continuous
use and can be installed
in a one or two-story
home. The backup system consists
of leaching
chambers (a concrete
box wrthout
a bottom or ends., about 13’ X 5’ X 2’) and
costs about $200.
with
hay)
Treat the tank of this system as you would a garden
hardwood sawdust or fine shavings
(peat moss, grass
after
each use.
compost heap; sprinkle
clippings,
chopped
After
some months, the insect
population
will
stabilize
and spiders
will
If flies
are a problem use sparingly
an organic
take care of fly larvae.
pesticide
(hargata,
pyrenone or nicotine)
inside
the tank;’ you do not want
to ki 11 the canpost I’ng organ 1smo. Use sawdust after, garbage deposits,
especially
in rusxner tfme; it helps to control
the insect eggs that come in
the house on fresh fruits
and vegetables.
year
Raw materials
must be raked down and poked once a month during
and less frequently
after
that.
the
first
Al 1 construction
must be f I reproof.
Enginesring
plans are available
for $10 (complete
instructions).
These plans are designed for people with
It is assumed that the builder
knows how to cut
some building
experience.
through
floors
and walls and that the builder
will
read a good book on waterproof concrete
before beginning.
This c-sting
toilet
is one of the few that permits
the toilet
to be
Of course,
this design requires
placed in an existing
second-story
bathroom.
additional
lengths
of plumbing,
but for those who have hang-ups about comthis
is probably
the answer.
post toilets
being confused with outhouses,
34
FIGURE
3.4
35
FIGURE 3.5:
Second Floor
Application
of Maine Tank
packet on the Maine Tank is detailed
and exPeggy Hughes ’ information
As with other composting
toilet
systems,
deviation
from recommended
pt icit.
practices
usually
creates
problams.
is
The Maine Tank, when used properly,
relatively
maintenance
free and is one of the few models which
is fireproofed.
E. BATCH COMPOSTER
lnformat
ion:
Appalachian
Mountain
Club
Corham, NH 03581
Attn:
Edward L. Spencer
(603)
466-2721
The batch composter
is designed
to treat
small
volumes
of waste quickly.
It works with,
but is separate
from, an outhouse,
and waste must be transferred
from one to the other
(see below).
Total cost for installation,
including
transportation
to site without
outhouse
is $155; with
outhouse
and
transportat
ion, $1000 to $1200.
Necessary materials
include
fiberglass
sandwiched
in a wOOden frame (top),
3” exterior
grade plywood
(sides
and
bottom not fiberglassed),
perforated
aeration
tubes of PVC, hooks and eyes.
The unit weighs about 75 pounds.
FIGURE 3.6:
. .--
This unit can accorrmbdate 60 overnight
visitors
per site or 200 visitors
and
should
be installed
at campper season (300 gallons
of treated
waste),
Compost
using
a
bark
bulking
agent
is
required
for
maintenance.
The
sites.
unit needs regular
but not continuous
attention
and requires
a manager (someFeces from the outone to get to the site to maintain
the compost process.
house drop into the collection
chamber where they are mixed with the bulking
agent at 10 gallon
or 90 pound intervals.
Temperature
of 140°F for 36 hours
should be maintained
and compost must be allowed
to rest for seven more days.
Handling
is required.
Insect problems can be controlled
by covering
all
inlet
vents and pipes
with fine mesh screening
and keeping the toilet
seat closed with a tight
seal.
spray diluted
pyrethrin
(organic
pesticide)
on
If insect
problems persist,
Flies
usually
indicate
that the pile
is too wet.
Allow
the cmst
pile.
a dry crust to form on the surface
of the pile to further
discourage
odors
and flies.
Material
must be transferred
from the outhouse
to the bin cornposter whenAdd 40 pounds of
ever approximately
10 gallons
of waste have accumulated.
are
drying
materials
and food scraps.
Two turnings , at seven day intervals,
Remove composted materials
and let them dry so they can be reused
requl red.
Haterial
can be stored.
as a bulking
agent.
Start-up
requirements
involve
adding a two-to-three-inch
layer of drying
material
such as bark to the collection
container
and sliding
it under the
It requires
high
This layer will
absorb liquid
and reduce odors.
pr Wcellulose
content
materials.
onto
The end product
can be reused
the forest
floor.
F. BIN COMPOSTER
for
composting
I nformat
ion:
fresh
wastes
or turned
Northeastern
Forest
Experiment
Station
Forestry
Sciences Lab.
Concord Post Road
P.O. Box 640
Durham, NH 03824
(603) 868-5576
Attn:
Ray Leonard
leak-proof
box to be used at backThe bin composter
is a fiberglass,
The total
cost for incountry
shelter
sites
in conjunction
with privies.
Necessary materials
for construct
ion Include
stallation
is $85 to $100.
Fiberglass,
exteridr
grade plywood,
stock softwood/hardwood,
nails,
polyester
repin,
hooks and eyes, ftberglass
mat, and two perforated
PVC tubes.
No
retrofitting
is required.
This free-standing
unit can accommodate five or mOre persons/night.
Aerobic
and thernmphIlic
processes
are aided by using hardwood debarker
waste for maintenance
to eliminate
odor, absorb moisture
and provlde
nutrients
to the decomposing micro-organisms,
No insect
problems have been
indiica&d.
It uses a solar panel which helps to reduce liquid
build-up
through
evaporation.
,,
I
38
FIGURE 3.7
Matertals
collected
in the privy
container
must be dumped into the
composter
bin when fuii,
wh Iti -c!epenc+ upon frequency
of privy
usage-approximtely
20-plus
days.
Start-up
criteria
include
close proximity
or access to a privy,
and the
rmney and materials
to construct
the composter
bin.
The end product
can be
scattered
on the forest
floor
or used to recondition
the soil
in worn areas
(campsites
and along trails).
This composter
bin has a ten-year
lifetime
and this type of system
appears to be just what the doctor ordered
for backcountry
campsites.
It
could probably
be used at remote summer homes If regular
maintenance
were
provided.
Maintenance
is the major drawback;
however,
if sanitary
precautions
(e.g.
rubber gloves)
are taken,
this shouldn’t
pose too much of
a problem.
39
G.
BIO RECYCLER
lnformat
ion :
Bio-Recycler
5308 Emerald
Drive
Sykesville,
MD 21784
f;;’
795-2607
: Jeremy Criss
The Bio-Recycler
effectively
blends modern and appropriate
technologies.
Jeremy Criss has put at least twenty years of experience
into perfecting
this
composting
toilet.
The sire and shape of the composting
container
make major
retrofitting
unnecessary.
The composting
container
takes up about the same
amount of space as a large hot water heater or furnace
(three
foot diameter
by 6’6” height).
The only retrofitting
is to replace
the regular
flush toilet
with the Bfo-Recycler
unit.
The unit
is vented through
the wall rather
than
through
the roof and is screened to prevent
flying
insects
from entering
the
container.
Total cost for installation
is approximately
$1600.
Materials
list
and
materials
can be obtained
from the Bio-Recycler
supplier.
The unit uses 110
volt electricity.
Power is needed only when the toilet’s
vacuum pump is in
It is not recomuse.
coils
or elements.
The unit requires
no fan, heating
mended for recreational
use or part-time
occupancy homes or public
facilities,
as it requires
maintenance , and drying-out
cannot be permitted.
The feces are broken up and aerated
during
the first
few seconds, as the
unit uses a high velocity
vacuum delivery
system that transports
excrement
from the toilet
to the composting
container.
Each time the toilet
is used,
about four ounces of water is used to rinse down the sides and keep the actual
toilet
clean and free of contaminating
materials
which attract
flies.
The
addition
of four ounces of water also serves to effectively
reduce
fire
However* warnings
against
adding cigarettes
and hot ashes should
hazards.
be Posted.
Kitchen
garbage is added through
the loading
hatch directly
into the
As materials
break down, they drop into the lower
compost ing container.
container
(which takes several
people several
years to fill.
According
to
triss,
the system has no problems with odors,
flying
insects
or urine
buildhouses redworms (Eisenia
foetida)
in the
up* And the compost container
lower chamber.
The redmrms eat the aerated
feces which has been mixed with kitchen
waste and broken down to the point where the heat of decomposition
doesn’t
kill
them.
These worms function
the same in the composting
container
as
they do outdoors
or in compost bins.
The resulting
compost is rich in worms,
castings
and capsules,
which can be removed as needed and used in the garden.
iaboratory
testing
is recommended as the worms may have concentrations
of
heavy metals in their
bodies or in their
castings
and these metal concentrations may have toxic
effects
on the human body.
Urine flows through
the upper and lower chambers and drains
into a
This liquid
is a combination
of urine,
water and
‘compost tea’ bucket.
any liquid
runoff
from the aerated
feces and kitchen
waste.
The compost
tea
is odorless
and almost black in color.
It is recommended that the
Potential
buyer check with the local
health
department
to find out how the
campost tea should be collected,
stored and ultimately
used (or disposed).
Usually
it is collected
in a 5 gallon
plastic
bucket.
It can also be used
as an indoor plant and outdoor
ornamental
plant
fertilizer
and/or applied
to outdoor
compost p i 1es.
The compost tea also is beneficial
in septic
tanks because of the nutrients
it supplies
to the anaerobic
process.
The Rio-Recycler
effectively
eliminates
odors by keeping the vacuum
tube to the compostfng
chamber closed except during
use.
In addition
to the
tube which is only open durtng use, the Bio-Recycler
1s vented to the outside
through
the wall.
This vent 1s screened to keep out flying
insects.
The cornposting
container
is equipped with an observation
window.
Through
it, flying
insects
can be seen and the height of the container
contents
can
be checked.
No insects
in the vicinity
of the container.
The
fly
vacuum aeration
system provides
enough air to sustain
them in their
environnaent.
Hr. Criss is considering
offering
the Bio-Recycler
in kit form.
Orders
would include
some pre-formed
parts and the unit would require
some assembly.
No price has been affixed
to the kit at this time.
However, it will
afford
the kit purchaser
a considerable
savings when compared to the pre-assembled
Bio-Recycler.
41
APPENDIX A
The following
report was written
by Jon Averill
of Hinton,
Vest Virginia.
Under contract
with
The National
Center for Appropriate
TechnoIogy,
Averi ii constructed
a wood-frame
compost ing
toilet
for a low-income
family
in West Virginia.
This report
is a summary of his construction
details,
including
an options
chart and materials
check list.
SIJHRARV: YOOD FRME COnPOSTING TOiLET
General
description:
This
unit
is designed
to be built
on site with commonly available
matit has a Cltvus-type
sloped bottom, and is constructed
of wood and
ferro-cement
for several
reasons:
erial
s.
::
3.
box can be well insulated
ferro-cement
has a degree of elasticity
madlum allows a great deal of design
Ratroftt
cracking
requtrements:
it requires
4~6x8 ft.
Unit is large:
considerably
more room for the construction
Number of persons
unit
Recormnended for
Type of structure
“’
of space
process.
for
installation,
and
can accomodate:
four
people
in which
Uesigned primarily
for
can be used in a free-standing
in a crawl
to resist
freedom
the
full
toilet
basement
privy.
time.
is to be installed:
or attachment
Unit is not
space.
42
to house;
practically
basic technique
constructed
Da&up
or greywater
system:
Unft uses a drain and separate
urinal;
so far we recommend backup system
be a reduced-site
septic
tank and leach field,
and toilet
effluent
be also
fed into the system.
Hatntenance
requrrements:
Daily
addtttons
of kitchen
garbage and “dry flush”
material
(peat mdss,
Monthly
15 minute poking of the
chopped straw,
forest
soil).
pfle with a stick
(see pg. 12).
Monthly
service
of the fly trap (2 min.).
After 2 years, emptying
every three months.
aged sawdust,
Insect
problems
Entire
box and are
Frequency
and control
methods:
inside of unit
Ts black.
Insects
fly
poisoned with chemical
no-pest
strip.
in handling
raw materials
into
an attached
and end products:
Empty end products
Poke raw matter once a month wtth.a
stick.
every three months (approx.
1D gal.)
after
2 year start-up.
Start-up
tfre
lke
window
once
requi remnts:
Use six inches of non-sterile
bottom of container.
Cover
peat moss, forest
sot\,
etc.
drain with gravel
and straw.
across
en-
of end product:
After
burlal
non-food
crops.
Disadvantages
Thi
cost
under
6” of
sol1
of
this
wood-frame
tr
htgh;
the atr
until
considered
safe
(1 year);
use on
unit:
system
compllcatsd
to build,
Wood in contact
This design can be hqwoved upon; it is
In wood-frame
toilet
drslgns.
It should
toward nwe afftclent
design.
wtth tb ground can be problemmttc.
in no way cmstderad
the final
word
Bs vtawad
Cost
for
as a stagptng
toilet
rnstaltat
stone
ton:
$400 to $500 de pen di ng upon materials
greywater-blackwater
treatment
system.
used;
add to this
the cast
of
:”
B.
t
CONSTRUCTI ON PROCEDURE:
Foundation:
2716 pounds weight
1500 pounds might
4216 pounds total
of compost
of tollet
weight of loaded
unit
Unit should be built
on exlsting
basement slab;
18 inches of gravel;
or
a poured 5’xg’
fcmting,
6 inches thick
around perimeter
and 4 inches in center.
Use 44 gallons
water per sack of portland
cement, and 2 parts sand, 3
parts gravel
(lf
inches aggregate).
18.75 cubic
ft.
concrete
Htx sand and cememt first,
11% more tensile
strength).
ment sandwiched wlthin.
- .7 cubic
yd.
add water and then
Use polyethylene
gravel
under
(in
slab
this way cement gains
and wire reinforce-
Frame:
Bui id stud
sections
to the
appropriately).
Use temporary
sect ions.
Put top on only
sides.
Caulk al 1 seams.
diagonals
after
unit
on sides and nail
bottom
is In place (lap plywood
Have pipeg (alr ducts)
cut to fit
and slide
them in place
Interior:
Seal the pipes as they exit
cement has cured (keep wet) for two days.
Prepare baffles
outfrom the box with sillcone
caulking
and black asphalt.
side and Insert
them last.
after
Basfc
terra
proof
C.
Host other construction
details
can be gathered
from the blueprlnts.
Refer to the listed
crlcarpentry
and masonry skills
are required.
to know what condftrons
must be achieved
(i.e.,
air-tight,
motstureUse material
list
as a guide for construction
sequence.
bolt).
WQTE TO DESIGNERS MD BUILDERS:
At the time of publication
our flrst
unit
1s awalting
cement work.
hours of plannlnghamgone
lnto the design of this unit,
but we ourselves
and time.
haven’t
completed
round one yet, due to lack of resources
Many
Ye are soon to begin burldIng
another
unit and plan to use the wood
frama cunpostlng
totlet
plans only as a guide.
Do not take these plans as
-0 use your heads, and find ways to stmpltfy
and-rcpon
the
%=F
es gn, wfthout
sacriffc!ng
the necessary
water tight
shall
etc.
Consider
these posslbiltttes:
1.
ElMnate
battom stud sections;
build sidewall
onto slab, nail wire
through vfgid insulation
and onto slab.
Build an air staircase
with
Build stairdouward rlopfng
steps; slope slab for liquid
dratnage.
case with 1” galvanized
pipe or heavy rebar wrapped with diamond mesh
and coated
cement
= (similar
to Hax Kroshell
Is new unit
at Faral lones).
2.
Use cement block and an air staircase
technique
-- fill
block with concrete and Insulate
G’I the outside
of slab and block so all the concrete
acts as heat storage.
(Paul Gallmore
in North Carol ina is designing
one.)
3.
Expand mod
frame des!gn to accamdate
2 - 4 canodes;
partition
the chambers.
Hake haif of the chambers Inactive
half- of the
follou
a rotation
procedure
slmllar
to Farallones
vault
privy.
between
time;
OPT I ONS
Trlel
unit
enterlot
a)
b)
c)
d)
I)
aerat Ion
l-inch
treated
plywood bottom
black fiberboard
sheathing
on
walls and top
61 mi 1 polyethylene
aluminum newspaper prfnt
plates,
caulked between sheet laps.
asphslt
coating
a)
b)
c)
d)
e)
f)
Recommended
construction
s-e)
Other
opt ions
b-e)
$
or creosoted
over polyethylene;
d)
best to use a 6-inch
ventplpe
with a constant
operating,
long
life,
moisture
resistant
11-15
wifght
fan, strapped
inside a
removable section
tar paper, chicken wire,
stucco (applied
in place)
l-inch
boards (heavy)
a)
b)
air stairstep
technique
natural
thermosiphoning
(create
draft
from hot
air rising)
We tried
coattng
fiberboard
with a
commerbial- fiberglass-cement
mix;
WC thought
this would strengthen
the
board and make It seamless,
vermin
proof.
Coating peeled off in sheets.
Inventor
had success using white glue
for bonding;
we were in hot sun...
further
experiments
could bring better
results
but.. .?
a)
thlnwall
pipes;
perforated
any pipes placed
draint fle pipes;
fn such a way as to impede flow of
the pile
direct
cold alr input
tnstal lat ion without
a fan where
electricity
Is available
a-b)
What to
avoid
$-Inch
stalned
plywood nalled
caulk seams
three 3-inch
PVC thickwall
pipes cut out In bottom;
run
through wall at upper end of
chamber and down to the baffle
afr induced to these tubes through
4-Inch
pipe to kitchen
ccl 1 ing
summertime outslde
atr fntake opt.
4-Inch
ventstack
wfth Italian
made
plastic
barrel
fan
insulated
attlc
area with black roof
(ventpipes
pass through)
16-Inch wfnd turbine
on roof
b)
c)
approximate
total
cost
$300
$500
$400
OPTIONS
Trial
unlt
s i te preparst
a)
b)
c)
d)
Ion
prepare level-surfaced
pit
where unlt
fs to be placed
fill
with 1-inch gravel
sl Ide unl t in place
partially
bury with dratn
tile
on top und side
interior
frame
a)
b)
rough 2x6’s on 164nch
centers
creosoted
R-19 flberglass
a)
b)
c)
d)
o)
Recommended
construct
ion
Other
opt ions
What to
avoid
a)
b)
excavate
and level
site
pour reinforced-slab
foot irrg
5”x9’,
6 inches thick
around
perimeter
and 4 inches thick
in center
a-d)
use existing
basement slab
a)
lf-foot
a)
gravel
bed
b)
flbered
paper (lumber
wrapping
free from Iumberyard)
&inch
extended diamond
mesh attached
wlth galv,
roof nails
coat with masonry cement,
sand concrete
mix
Thoroseal
Block Sealer
black roof coating
planed 2x6'~ on 160Inch
centers
creosoted
R-19 fiberglass
same as trial
planed or rough
169inch centers,
flame retardant
sheet insulation
a)
2x4’s on
creosoted
foam or
for a free standing
unit use
block or pressure
treated
foundat ion on appropriate
footing,
or pole foundation
b)
direct
contact
of wood to the
ground unless
it is pressure
treated
and seams tightly
sea 1ed
green lumber in frame:
shrlnkage
could crack the
cement, moisture
in sealed
walls could start
rot
cellulose
hard to install
and
settles,
it is not appropriate
for small framed compartments
tar
unit
paper
do not dpply
!t is likely
ing the first
cement mix lf
to freeze durtwo days
S-la
Materials
List:
w&
Framed t&posting
material
guant i tY
port 1and cement
medium grade sand
lh inch aggregate
6 mil polyethylene
reinforcement
wire
2x6’s’
8’ length
(planed)
2x6’s.
12’ length
(planed)
2x4’s.
8’ length
160penny nails
R-19 Fiberglass
insulation
creosote
9‘ Plywood
galvanized
siding
nails
caulking
compound
fibered
paper
&$‘.x:~~~
dlamnd
mesh (gal -1
4 bags
3 ton
4 ton
25 sq. yd.
5‘x9‘
galvanized
rtiflng
nails
staples (staple
gun type, f”)
amsonry cement
Thor0 Seal Block Sealer
black asphalt
roof coating
1“ boards, 6“ wide, 12” lengths
drain
drainline,
3“ PVC, elbows
3“ PVC thfckmll
4“ PVC ‘T“ s
4“ to 3“ PVC reducers
Toilet
cost
f2
“2
$8
$5
$25
$52
::
5 pounds
125‘ (run)
2 gal
8 sheets
5 pounds
3 tubes
150 sq. ft.
$4
:s
$80
if
$0
isi
$1
:‘pounds
1 package
13 sacks
30 pounds
1 gallon
2
1
10“
24‘
“lo”
$30
:
20‘
f:
$15
$5
$9
::
20’ 4” PVC thin-11
4“ PVC 450 “L“‘S
6” PVC coup1 lngs
11-15 watt long 1 ife fan
cord, suspension
wire
6“ PVC
8“ stack cover,
cap
silicone
caulk
screen
1“ hoard 9&l‘ width,
8‘ length
glass
glue, putty,
caulk,
nails
hinges
2 sets
$8
metal brackets,
4
$3
$10
urinal
conrnode
screws
4
2
1
1
if
s’i
$15
15’
3‘
1 tube
: sqg ftm
53“XlOli”
approx.
approx.
47
;:
$1
$2
$1
$1
$20
purpose
footing
footing
and interior
footing
footing,
exterior
foot i ng
frame
frame
frame
frame
frame
frame, exterior
exterior,
chute,
baffle
exterior
exterior
interior
interior
interior
inter for
interior
inter ior
interior
inter lot
inter ior
line to leach field
interior
air ducts
air connection
box
air connection
box
air intake
air intake
fan assembly
fan assembi y
fan assemb Y
vent stack
vent stack
interior
a r ducts
air intake and exhaust
fly-trap
fly-trap
fly-trap
fly-trap,
door
baffles
Infestation
by germ-carrying
flies
has been a major problem of corncosting
Flies are not harmful
in the toilet,
but they cause trouble
when
leave the compost and enter the room, attracted
by the light
above the seat.
to1 lets.
they
So:
We painted
the
underside
of a Toa-Throne
seat
and the
camnode liner
black as to limit
reflection
of light,
then added this fly trap.
Results:
the
flies are not all dead, but they are under control.
Fruit
flies
are the least
apt
to be attracted
to the Bye Bye Fly Trap; house flies
almost alNays enter
and die.
Ml1 have more information
later
(i.e.
types and quantities
of flies,
effects
of different
wattage or color of lights).
Also we plan traps for other
cmrclai
models such as Clivus,
Humus, and Huiibank.
You should be able to
easily
adapt these plans to fit a homemade waterless
toilet.
We are interest, and we welcome nodifications
on our plans.
ed in your experiments
How to Build
Haterial
s:
the Bye Bye Fly
Trap
(for
under
$2)
*one plastic
gallon
milk jug with somewhat fiat
sides
*one margarine
or similar
plastic
boat (a non-crackable
plastic
with a 7” diameter,
4-5” deep, and a tight-fitting
lid
4” x 5”
*snm\i piece of glass , approximately
*caulking
ask:ng
tape
*no-pest
strip
*12’& nylon fish 1 lne
*night1 ight,
or refrigerator
i lght (15 watt bulb),
socket
gun,
sharp
scrap
knife,
strips
of plastic
for
welding
Tools:
soldering
rods
How to:
With a Toa-Throne,
cut the handle section
out of the inspection
opening 1 id.
This is hard plastic
but it can be cut (so can your
hand be careful).
Then take the lid to the plastic
food container,
place it, top down, on the top of the toilet
lid.
Slowly melt a
strip
of plastic
(l/8
inch wide) to join both lids.
You can achieve
an airtight
%eld.”
Be sure to melt all three surfaces
evenly so
that they will
bond together
into one piece of plastic.
Cut out the center of the food container
lid,
approx.
5” diameter.
Cut out the bottom of the food container
with a hole slightNow “weld”
the food container
bottom to the
ly smaller
(393P).
wails are thin and melt
side of the ml ik jug (careful
: milking
through easily).
Hake airtight.
Cut a hole in the milk jug through
container.
Hake it the same size.
the
bottom
of the
food
Cut a hole in the jug on the opposite
side, the same size or
sl lght ly swi ler.
Edge the hole with caulking
compound.
Put the
Neatly wrap masking tape
small piece of clear glass on the caulk.
araund the jug in two places to tightly
hold the glass to the Jug.
tape,
Hount the
but only
light
in such a way that it will
not burn the Jug or
(Taped or suspended over the glass.)
touches the glass.
Put a small hole in it, thread with
Quarter a no pest strip.
the nylon line.
Secure it ln the mouth of the jug by running
the
Replace
tine through
the top of jug as pictured,
and tie to handle.
Hake sure the jug lid,
like
every month with a fresh no-pest
quarter.
everything
else,
Is airtight.
Put the inspection
lld section
in place,
then attach
trap section,
snapping
it into the inverted
container
lid.
To empty trap,
Flies may be too chemically
contaminated
to
shake flies
from jug.
put in toilet.
Flies entering
the trap ~111 die in about 30 seconds.
The strip
will
not radiate
enough poison into the chamber of the
toilet
to damage the compost.
49
REFERENCES
1.
Warshall,
2.
and Water
National
Sanitation
Foundation,
Wastewater Recycle/Reuse
Conservation
Systems.
Standard Number 41, November 1978,
Ann Arbor,
Michigan
3.
Stoner,
4.
Weize,
5.
6.
Nesbitt,
Patti,
Daniels,
Ida,
7.
Gotaas, Harold,
Composting,
Sanitary
Wastes, World Health Organization,
8.
Golueke,
Clarence,
Rodale Press,
9.
Wagner, Edmund 6 J.N. Lanoix,
Excreta
Disposal
for
Cormsunities,
World Health Organization,
1958
10.
Clark,
Zandy, Alternative
Waste Treatment
Association,
Star Route 3,
1978
Bath, ME, Written
and Personal
Communication,
March c April,
11.
Averill,
Jon, Box 88, Hix Route, Sandstone,
Communication,
March 8 April,
1978
12.
Hal 1-Beyer,
Bart
PP. 72-75
13.
Bond,
14.
Farallones
Institute,
Technical
Bulletin
#l,
Occidental,
CA and Berkeley,
CA 1975
15.
Maine
Plumbing Codes - Part II, Private
Sewage Disposal,
Health Engineering,
State House, Augusta,
ME
16.
Office
of Appropriate
Water Disposal
17.
Cooper, R.C. S C.G. Colueke “Public
Health
Treatment”
Compost Science,
May/June,
Peter,
Septic
Tank Practices,
Carol Hipping,
Inc.,
1977
Paul, Science
New York, 1963
ed.
Mesa Press,
Goodbye to the
of Biology,
Flush
2nd edition,
NCAT Publication
#
NCAT Publication
, Source
Separation
Process
Countryside,
Waldbott,
co.,
George,
1973
20.
Malsanos,
Lois,
21.
Anthony,
C.P. G N.J. Kolthoff,
Textbook of Anatomy
C.V. Mosby, Co., St. Louis, MO, 1971
22.
Fox,
23.
Cl ivus
et al
Multrum,
Maxcy-Rosenau
- Preventive
Appleton-Centry-Crofts,
Epidiemiology,
Trouble
Privy,
Division
of
Rural
Waste-
Medicine
1963
Environmental
Assessment,
Waste
C.V.
and Public
Pollutants,
Mosby,
Man and Disease,
Shoot inq Manual,
1978,
Control,
of On-site
19.
John,
January
1977, pp. 8-11
Sartwell,
Phillip,
ed.,
Health,
9th edition,
Health
B Small
and Personal
Composting
Aspects
Principles,
Areas
WV, Written
18.
et al
Rural
1979
of Organic
1956
and Its
FInal Report - Phase I,
September,
1977
of
Co.,
Bibliography,
Handbook of Environmental
CRC Press, 1973
Effects
Press,
Book,
Disposal
and Reclamation
Geneva, Switzerland,
Micro-organisms”
Technology,
Alternatives,
Health
Rodale
1979
, Greywater,
#
Richard 8 Conrad Straub,
Volume II, Solid WBstes,
Toilet,
McGraw Hill
Compostinq,
A Study of the
Inc.,
Emus,
PA, 1972
“Mighty
1976
14A Eliot
Co.,
C.V. Mosby
St.
Louis,
1977
and Physiology,
Macflillian
Street,
Co.,
1970
Cambridge,
MA
I-^-^
24.
Guttormsen,
Dag “Some Aspects of Composting Toilets
With Specific
Preference
to their
Function
and Practical
Applications
in Norway”,
145-151,
Individual
On-site
Wastewater
Systems,
Proceedings
PPof the Fourth National
Conference,
1977
25.
Ehlers,
V.M. s E.W. Steel,
McGraw-Hill,
1965
26.
U.S.
Department
of Agriculture
Fanners Bulletin
#1408,
27.
Riley,
28.
Nichols,
Wayne H. Analysis
of Bacterial
of the Clivus
Wultrum,
Center for
Washington
University,
St. Louis,
29.
Fogel , Margaret,
Ph.D. Chemical Analysis
of Clivus
Multrum Compost,
Ciivus
Hultrum,
U.S.A.,
14A Eliot
Street,
Cambridge,
MA, 1977
30.
Fogel , Hargaret,
Ph.D. Analysis
of Stack Gases from Two Clivus
Conqxmting
Chambers, January 1977, Clivus Multrum,
U.S.A.,
Eliot
Street,
Cambridge,
MA
31.
Kroschel,
Max Experiences
with Owner-Built
On-site
Waste Management
Systems in California,
pp. 173-187,
individual
On-site
Wastewater
Systems, Proceedings
of the 4th National
Conference,
1977, Nina
KcClcnlland,
cd., Ann Arbor Science,
1978
32.
Personal
33.
Personal
Communication
with
Technology,
Sacranmto,
34.
Personal
8 Written
Environmental
35.
Personal
Comunication
Center,
#4 East
16.
Written
37.
Written
Tom, P.E.,
Written
Cfnmnunication
Municipal
Sanitation,
“The House Fly
November 1926
Conmnunication
- Farallones
to
Rural
6th
Ida Daniels,
Center,
March 5, 1979
Multram
14A
May 1979
Office
of Appropriate
Department
OR 97207
with Brian Cook, San Diemas Equipment
Bonita,
San Diemas, CA, April
1979
Patti
It”,
in the Final Product
of Natural
Systems,
Conmntnication
with Thomas Berkemeir,
Quality,
State of Oregon, Portland,
with
edition,
and How to Suppress
Populations
the Biology
MO, 1976
Malcolm Walker.
CA, May 1979
Comunicat
ion with Donald
Engineering,
State of Maine,
KE 04333, March 1979
Comunicatlon
6 Rur?l
of
Development
Hoxie,
Director
of Division
of Health
Department of Human Resources,
Augusta,
Nesbltt,
May, 1979
..-
_l_l
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising