Course1_Unit3_Technology_overview_D_F - unesco

Course 1 Unit 3
Part A B C D E F
Overview of technologies for ecosan
(toilets and treatment)
Mariska Ronteltap
Course 1 Unit 3
Overview of technologies for ecosan
(toilets and treatment)
Content of Part 1 (separate file to keep file size < 10 MB):
Part A: General issues: groundwater pollution and urine precipitation
Part B: Overview of technologies for ecosan concept
Part C: Waterless urinals
Content of Part 2 (this file):
Part D: Overview of toilet types
Part E: UDD toilets
Part F: UD water-flush toilets
Course 1 Unit 3
Part D: Overview of toilet types
“So – shall we
split up ?!”
With or without urine
diversion (UD)
UD = keeping urine
and faeces separate at
point of excretion
What is underneath your bum when you
use the toilet?
• The user interface (what the user sees), e.g.:
– Toilet seat / pedestal
– Squatting pan, squatting slab
– Urinal
• The receiving unit (what the user doesn’t see), e.g.:
A pit (= hole in the ground, not water tight)
A vault (= container for storage + treatment/drying, water tight)
Septic tank, cess pit
Pipes to sewer system and treatment plant
 many toilet photos only show the user interface
Example: VIP latrine with two pits (used by alternating every 6 months)
User interface
Receiving unit
(in this case
VIP = ventilated improved pit
Urine into the ground
Many different toilet types…
Historical dry toilets
“Modern” water flush toilet (?)
“More modern” UDD toilets (??)
Should we be talking about “ecosan toilets”?
• I would strongly advise not to use the term
“ecosan toilet”
• People usually mean a urine diversion
dehydrating (UDD) toilet
• Remember ecosan is not limited to a specific
technology (or toilet type)
• But all sorts of toilet types can play a role in
an ecosan concept, even the conventional
water-flush toilet (see next slide)
• The word “dry toilet” can also be misleading
(urine is not dry)  use dehydrating instead
Some people say that
ecosan toilets are those
that have urine diversion
Others say ecosan toilets
are those which allow
reuse of urine and faeces
The term “ecosan toilet” is
short, nice and catchy,
and translates well into
other languages, too!
 You have to make up your own mind
But can a non-UD water-flush toilet (“WC”,
“normal toilet”) possibly be part of an
ecosan approach?
 Yes! I will show you an example at a restaurant and
farm “Waldmichelbacher Hof” in Germany (in Course
2 Unit 4 “Introduction to anaerobic treatment
– Toilets + animal manure + organic waste  to
anaerobic digester
– Digestate is applied to fields as fertiliser, therefore
closing the loop
 Remember: Ecosan approach = aiming for
sustainability and closing the loop (between
sanitation and agriculture) with whatever technology
Range of available toilet types
Course 1 Unit 3
Toilet type
Dry mixed
Faeces + urine mixed, no flush
Conventional pit latrine; VIP latrine;
composting toilet
Dry F/dry U
Faeces without, urine without
UDD toilet, waterless urinal
Dry F/wet U
Faeces without, urine with flush
(mini flush)
Wost-Man, Sweden (UD toilet)
Wet mixed
Faeces + urine mixed, vacuum
system (very low flush)
Roediger, Germany, vacuum toilet
~ 1 L/flush
Wet F/wet U
Faeces with, urine with flush
UD water-flush toilet by Dubletten,
Roediger, Gustavson. Also called
“NoMix Toilet”
Wet mixed (gravity)
Faeces + urine mixed, big flush
Conventional flush toilet (WC), ~ 10 L
UD = with urine diversion
UDD = Urine diversion dehydrating
VIP = Ventilated Improved Pit
* Often wrongly called “ecosan toilet”
Increasing water use per day
(they can all be used within an ecosan approach; for photos see next slides)
Pictures of different urine diverting toilets
Wost-Man, Sweden
GTZ, Mali
dry F/dry U
faeces without, urine without
dry F/wet U
faeces without,
urine with mini-flush
Roediger, Germany
Dubletten, Sweden
wet F/wet U
faeces with, urine
with flush
Collection vault for faeces (for UDD toilet) and urine tank are commonly in basement or below the
Toilet type
Water per
Water per urination
Water use (L/cap/d)
Dry mixed
Dry F/dry U
Dry F/wet U
Wet mixed (vacuum)
Wet F/wet U
0.1 (Dubletten)
2.5 (Roediger)
6.9 (Dubletten)a
16.5 (Roediger)b
Wet mixed
Conventional urinal
Waterless urinal
Increasing water use per day
Daily water consumption estimate for
toilets and urinals
Based on: 1 defecation event per day, 4 urination events per day
Urine-soiled toilet paper must go to separate bin
Urine flush water is collected with faeces (urine collected pure by means of a valve, see later in this presentation)
Two types of UD toilets
UD waterless toilets
– UDD or composting
– Not “forgiving” to misuse
– Requires shift in thinking for those that are used to
waterborne sanitation
– Need separate drain hole if anal washing with
water is custom
– Suitable for slums and areas with unreliable water
– But not just a technology for the poor
UD water flush toilets
Very similar to conventional water-flush toilets
Very easy to use, “forgiving” to misuse
Urine collected with or without water
Faeces always collected with water
(Eawag researchers call this the “NoMix toilet”)
Course 1 Unit 3
Examples for UDD toilets
(squatting type)
In rural China in 2005:
Approx. 1 million UDD squatting
toilets, or 0.4 % of total improved
55% of households have access to
improved toilets
(Source: Ina Jurga, CEEP, China)
Cost estimate: € 100 per toilet
(Source: Heinz-Peter Mang, Sept
Urine into this hole
Faeces into this hole
(move cover with 13
UDD squatting toilets in China
One bucket for toilet paper, one for ash, and a
watering can
Why add ash after defecation? For better
dehydration and pH increase, see Course 2 Unit 1
“Treatment aspects for urine, faeces and
With special ash dispenser (see
EcosanRes Discussion forum on
3 October 2006, Aussie Austin) –
ash dispense not reliable and
Frequently asked questions about UDD
Do men have to sit down when
urinating (if using a pedestal
No, they just have to aim well, but it is always better to
provide waterless urinals as well (exception: Roediger
NoMix toilet has a valve on the urine pipe which is only
activated by sitting on the seat)
What about menstrual blood?
Volume of blood is small; collected and sanitised
together with urine or faeces
Can muslims who use water for
anal cleansing use these
A separate collection system for anal washwater needs
to be provided right next to the toilet (see next slide)
Can children use these toilets?
Special toilet seats (for pedestals) are available; small
children would need help
Do you always have to add ash
after defecation?
Not necessarily, but adding either ash, lime, sand, soil,
saw dust has some advantages for the drying process
(see Course 2 Unit 1)
How can the toilet be cleaned?
A small amount of water is OK, even for dehydrating
Toilet designs for “washers”
(“washers” use water for anal cleansing, e.g. most Muslims)
(Non-washers = “wipers”)
Drain or hole for anal washwater
(close to wall so that it is not used
for urination)
SCOPE, India
CREPA, Burkina Faso
Course 1 Unit 3
Part E: UDD toilets
UDD toilets can be squatting or sitting (pedestal) type
Design drawings and more examples for UDD toilets are provided in
Course 1 Unit 4
UDD toilet squatting pan
Example: Single vault urine-diversion dehydrating (UDD) toilet
• This type of toilet is
often wrongly called
“composting toilet” or
“ecosan toilet”
• Note: the entire toilet is
typically above ground
Vault for faeces collection
and drying (no seepage into
ground from faeces vault!)
Removal of dried
Example of faeces vaults of UDD
toilets from the outside
Note jerry can for urine collection
CREPA, Ouagadougou, Burkina Faso
(Oct. 2006)
These two vaults of a double-vault UDD toilet are
semi-permanently closed. The pipe in the middle is
for anal washwater (discharge into a gravel19
Faeces vaults of UDD
toilets, inside view
Zimbabwe (photo: Edward Ghuza)
This vault above at CREPA headquarters in
Ougadougou, Burkina Faso, had only been used
for about two weeks (Oct. 2006).
Ash is added after defecation in all three cases
CREPA, ecological demo village, Burkina Faso
At CREPA headquarters in Ouagadougou, Burkina
Faso (West Africa), the staff can now also use a
UDD toilet (Oct. 2006)
Simple handwashing
device, see
later in this
Part E
UDD toilet
Pit latrine
Elisabeth demonstrating squatting
position on UDD squatting toilet
Inside view of double vault UDD squatting toilet
for anal
washing with
Bucket with ash stands
on top of the closed
second vault
Why add ash after
defecation? For better
dehydration and pH
increase, see Course 2
Unit 1 “Treatment
aspects for urine,
faeces and greywater”
Vault under squatting pan
Course 1 Unit 3
The new outside UDD sitting toilet (single vault) of Linus
Dagerskog, staff member of CREPA (junior professional with
The toilet is made from ferro cement, with painted toilet seat
Hole for vault vent pipe (yet to be installed)
Ferro-cement toilet during construction (vault opening at the front),25
and Elisabeth contemplating the future of UDD toilets in West Africa…
Ferro cement as a material for toilets (1/2)
“Ferro cement is sand and cement with wire to give it
A ferro cement pedestal is a lot more sturdy than the
plastic version but needs quite a bit of work to get a
smooth surface. The advantage is that it can be made
locally with a minor capital investment compared to the
plastic version which requires a roto moulder.”
Source: Richard Holden, 2 Nov 2006, EcosanRes Discussion
Ferro cement as a material for toilets (slide 2 of 2)
“Ferrocement is a great, great thing...something that made working daily with DTs so
great. In Mexico, we had a fairly extensive program of dry toilet and tank building. We
experimented with different prefab models of toilets and tried different methods of
construction for water tanks, and in the end, it was ferrocement that came to the rescue.
Ferro-cement simplymeans iron + cement and by layering cement on a wire mesh frame
we were able to create customized toilets (i.e. small toilets for children) and play around
with the location of the divider, etc. Also, we had some good experiences with building
large water cisterns.
The pluses are that the materials are general cheap and easy to come by, it is a very
relaxing and theraputic exerise that is quite forgiving (more on this later) to mistakes and
can be used quite creatively (we even dabbled in decorative flourishes!
The minuses are that it takes a bit of practice, a bit of patience and a willingness to
experient and fail. Because goodness knows we had some failures. The cement mix
must be just so, and luckily we had a local expert; after showing us once we were able to
replicate it.
The other minus (perhaps) is that the toilet is not entirely durable. It is quite good for
some years, when treated with a heavy duty paint that can be wiped down, but with use,
like all things, the paint wears and the cement chips. It is wasteful, but a nice toilet only
takes a couple of days to produce so it is often more time and cost efficient to make a
new one, rather than clean, patch and paint an old one.”
(Source: Elizabeth Tilley, 1 Nov 2006, EcosanRes Discussion Forum)
UDD toilet in
Richard Holden’s
house in
South Africa
Richard Holden is an ecosan
expert and regular contributor to
the Ecosanres Discussion Forum
For a description of his entire system
see separate presentation “UDD
system at Holden’s house” (Extra
“Upmarket” luxurious UDD toilets from
Swedish manufacturers
Course 1 Unit 3
Wost-Man “Throne” model
Note box (vault) underneath for
faeces collection compartment
Separett “Villa” UDD toilet
(see next 3 slides)
Cost: ~ € 650
UDD toilet in UNESCO-IHE building
Middle piece
to enlarge
urine bowl
Design detail: As the user sits down, the
faeces compartment opens (cover flap
fulfills aesthetic purposes)
Cover flap removed in May 2007 to
simplify operation (it sometimes got
stuck and dirty).
Middle piece also removed (needed
cleaning underneath).
Vent pipe
Faeces stains on this side are unfortunately not
uncommon (user should remove with moist
Sometimes users throw toilet paper into urine
This (female) toilet was operational at
UNESCO-IHE from May 2006 – Aug 2008
(photos taken August 2007) – for more
details see presentation under Assigned31
Toilet from the inside (faeces bin
Note some urine traces visible (needs
cleaning up)
Urine pipe to sewer
UDD toilet (supplier: Wost-Man, Sweden)
in Gebers apartment building in
Stockholm (August 2007) – in operation
since 6 years.
Straight chute from toilet’s faeces
hole to faeces collection bin in
cellar (emptied to composting site
about once per month by users
themselves, see next slide).
There is a ventilation system for
the chute and bin.
Top right: The Gebers apartment block during our
site visit (August 2007)
Top left: External composting of faeces and toilet
paper in garden
Left bottom: the amount of composted faeces of
80 people in 6 years!
Simple cheap handwashing devices for outdoor use
Remember: if people don’t wash hands after
urination/defecation with soap, your nice new
toilet may have little impact regarding health
outcomes !
Water reservoir with tap at
CREPA, Ouagadougou, Burkina
Photo by Peter Morgan (“ecosan
patriarch” in Southern Africa), Zimbabwe
Plastic water bottle, small hole with little tube at
bottom (the tube is from an empty ball pen). For
water to flow, open lid of bottle.
Note soap and gravel soak pit below.
Linus Dagerskog during handwashing
(CREPA, Ouagadougou)
facility on the left,
nicely integrated
into this outdoor
toilet design.
Note reservoir,
soap, tap and
gravel soak pit
Urine collection in
20 L jerry can.
When it is full it is
exchanged for an
empty one (circa
every 3 days for
family of 4)
(Remember ~ 1.5 L
urine per person
per day, see
Course 1 Unit 2)
Course 1 Unit 3
Information for users
(important for public
or shared toilets)
Prototype of waterless urinals for females
Questions to the ladies:
Would you use such a urinal?
Do you foresee any problems?
Have you seen other female urinals?
CREPA, Ouagadougou, Burkina Faso, Oct. 2006
Urinals for females considered “hip”!
The theatre in Winterthur, Switzerland had
female urinals in the ladies’wash room, and for
a long time they were the talk of the town!
Here you can see more examples
But not many are waterless!
Location of UDD toilet: inside or outside of
the house?
 Advantages of UDD toilet inside of the house:
– Improved security, especially for women and children
– Higher level of convenience and privacy especially at night
 Why are they still often built outdoors?
– People who had pit latrines before are used to having them
– People may not trust you when you say that it won’t smell
– May be easier access for removal of faeces and urine
– More suitable when toilet is shared by several households
– May be easier to retrofit if the house is already there and the toilet
is added later
Would you prefer to have a UDD toilet inside or outside of your house?
Other types of waterless (or “dry” toilets)
or just other names for the same thing
• Composting toilets (can be with UD, but are typically without) –
see Course 2 Unit 6 (“Introduction to composting”)
– Global Dry Toilet Club in Finland organises regular Dry Toilet
• Toilet types with names created by Peter Morgan, tried and
tested for rural areas of Zimbabwe, Malawi and Ethiopia (for
– “Arborloo”: Shallow pit composting, without UD (see success story
by SUDEA in Ethiopia of 10,000 Arborloos (2-page document can
be found under extra materials))
– “Fossa Alterna (FA)”: with UD, double-pit (note: this toilet uses pits
not vaults)
– “Skyloo”: with UD and two vaults (= UDD toilet)
– See next five slides for further explanations
Why the names Arborloo, FA and Skyloo?
 Peter Morgan: “I am the guilty one introducing all these
weird names. One has to add some colour to this otherwise
often drab subject.” EcosanRes Discussion Forum on 17 Dec 2006
 See the next 4 slides for further explanations of these toilet
types given by Peter Morgan
Elisabeth: I agree, it’s a nice idea to “popularise” the subject in this way; it’s just
that it confused me for a while, not knowing which toilet is which. And if everone
calls it different names, then, from a scientific point of view, it can lead to
confusions. But for the local population, it may be nice to have these colourful
What are other toilet names that you have come across yourself?
“The Arborloo, is the toilet which becomes a tree (hence Arbor… once again from
the Latin). This is entirely an indigenous concept, as trees have been planted on
filled toilet pits for generations in several countries in Africa and elsewhere. In fact
compostable kitchen “wastes” are sometimes thrown into disused toilet pits as the
volume contracts. Tomatoes, pumpkins and trees seem to grow naturally out of
such pits. Planted banana is very popular. But a wide range of trees will grow well.
In the Arborloo, the tree must be planted in soil on top of the composting
materials. It is very clear that the contents of this shallow (1 m deep) organic pit
helps plants of many types to grow faster. This is particularly apparent in areas
where the natural soil is poor and low in nutrients. In the Arborloo, the composting
rate is accelerated by the regular addition of soil and ash etc. These additions also
help to reduce the smell and fly nuisance.
The Arborloo concept may be popular at first, where there is space (rural), because
it is simple and cheap and the composted materials are not touched by human
hand. Also the merits of using composted human excreta on food production can
easily be observed.”
An elevated ring beam and slab are placed on top of the shallow pit (the slab has a
hole so that it functions as a squatting toilet)
Fossa Alterna
• “The word Fossa Alterna comes from Latin for alternating pit or
hole, in which the composting process of the excreta (faeces
and urine in combination) is accelerated by the regular addition
of soil and wood ash to the pit contents. It is a shallow pit toilet.
Normally pit contents may take some years to fully compost
depending on the condition of the pit. In this case composting is
normally completed in a year. The contents are dug out and
used in gardens, being mixed with topsoil. This concept makes it
possible to alternate pits on a yearly basis on a single site. In
warmer climates, and if plenty of soil/ash are added, the process
can be completed in 6 months - as in many areas in Malawi for
• Same type of slab is used as for the Arborloo
(this term is not commonly used)
• “The Skyloo – one steps up into it, above the ground and thus
takes the first step towards reaching the sky! It is a UD toilet, the
ultimate ecosan. Strictly it was the name given to a single vault
UD toilet where the solids (faeces, soil and ash) are caught in a
container, like a bucket. These are taken out and composted
elsewhere. The urine is normally led into a plastic container
through a pipe. I have used one myself for several years. It
works like a treat. In Malawi the name seems to have been
used to describe any UD toilet. Huge numbers of UD toilets are
being built in South Africa, as Richard has told us. SA has
• Remember: Skyloo = UDD toilet
Concluding remarks
(last slide from Peter Morgan’s posting of 17 Dec 06)
“All 3 systems have their place. It is possible, for instance to start off with an Arborloo (the
simplest and cheapest), and upgrade to either the FA or UD direct, using the same slab.
Similar upgrades are possible from Arborloo to VIP etc.
Each system has merits of its own and as with everything, some drawbacks. The flexibility of
the recycling process makes it adaptable to a wide range of circumstances.
In low cost ecosan projects supported in Malawi by CCAP (in the north) and COMWASH (in
the south) a total of 6126 Arborloos, 3493 FAs and 92 UDs had been built by mid 2006.
WaterAid, Malawi has also supported the construction of about 3000 units in Salima and
elsewhere, mostly FAs. These projects are based mostly in the rural areas.
As the unit costs of the system rises, less people are served with a given amount of aid or
external support. The systems are upgradeable. In the peri-urban areas a different
approach using UD can be used as we have heard from Siku. It is the flexibility of the
approach which is important.”
See also Peter Morgan’s report “An Ecological Approach to Sanitation in Africa: A Compilation of
Experiences”, which gives construction and operation details for these toilets
Course 1 Unit 3
Part F: UD water-flush toilets
UD water-flush toilets so far are all of the sitting type because they were
invented in Sweden
Gustavsberg UD water-flush toilet
What is a UD water-flush toilet?
 A toilet with separates urine from faeces
 Urine is collected pure (e.g. Roediger toilet) or
diluted with some flush water (e.g.
Gustavsberg toilet)
 Urine is collected in urine storage tanks and
treated or reused
 Faeces are mixed with flushing water and
discharged to the sewer
 These toilets are designed to work in
conjunction with a sewer
 The toilets are more expensive than conventional
water flush toilets
What are drivers for installing UD waterflush toilets?
Some water savings are possible
– However this is not so significant. E.g. with the Roediger toilets,
many users flush twice after urinating because the toilet paper
doesn't disappear with just one small flush (of course this could be
solved by teaching people to put toilet paper in a separate bin!)
Being able to collect urine separately with the following possible aims:
– Store and reuse as fertiliser, e.g. in Sweden
– Treat separately for nitrogen removal and then return back to the
wastewater treatment plant (e.g. this is the concept in Switzerland
and the Netherlands) - purpose is to unload the wastewater
treatment plant with respect to nitrogen load.
– Discharge urine to the sewer system only at night time, to balance
the load to the WWTP better.
– Treat urine separately for removal of pharmaceutical residues (likely
cheaper than treating the whole wastewater stream) - this is a major
reason for the Netherlands, where there is a worry about these
pharmaceutical residues appearing in surface and groundwater.
Roediger “NoMix toilet”
Photos from
GTZ building in
Eschborn, Germany;
56 toilets installed
Aug 06 (photos taken
Oct 06)
Cost: ~ € 1400 per
2-3 L for urine flush,
6-7 L for faeces
Rod which activates valve
for urine pipe when user sits
Course 1 Unit 3
Design feactures and operational issues
for Roediger NoMix toilets
Two different compartments for urine and brownwater
Urine is collected undiluted by means of a valve located under the toilet
seat, triggered when the user sits down
Operational issues:
– Toilet paper can also be flushed, but may not disappear with small urine
flush (better to put in separate bin); user can decide not to flush after
– If faeces end up in urine compartment, they can still be flushed and should
not contaminate the urine
– If user does not sit down, urine is collected together with brown water
(because valve isn’t opened)
– Cleaning is more cumbersome than for conventional water flush toilets
– This type of toilet does not necessarily save water but allows separate
collection of urine (see also for more
The issue of not wanting to sit down on a
public pedestal toilet
 Many females (and some males?) prefer not to sit down on
public toilets for fear of infections
– They rather hover over the toilet seat
– Perhaps those people would prefer squatting toilets?
 In the Roediger NoMix toilet, the valve to the urine tank is only
openend if the user pushes down on the toilet seat
 Similarly, the Separett UDD toilet has a flap over the faeces
compartment that opens when the user sits down
Urine drain hole and pipe to urine storage
Gustavsberg UD water-flush toilet at office
building of the Waterboard in Meppel, the
Netherlands (July 2007)
For more information see here:
Cost: ~ € 720
Since there is no valve, the urine is diluted
during the flushing (at least twice, perhaps even
Above: Small urine flush, controllable by the
user (with a separate flush button)
UD water-flush toilet from Swedish company
Dubletten (seen in upmarket house in Kullön
close to Stockholm, August 2007)
Adult seat
Child seat activated
Closed toilet
(note hinge for
the child seat
Interesting little design feature:
An in-built child seat to make the
open sitting area smaller for
Assessment of UD water-flush toilets
• Quite easily acceptable by those who are used to water-flush
– This toilet type has also been installed in the Eawag building in
Switzerland (20 toilets in July 06) and several places in The
Netherlands, e.g. KIWA Water Research building in Nieuwegein (2
toilets in Sept 06)
• Not an appropriate solution for low-income areas with waterscarcity problems or where the capacity to treat the faeceswater mixture is not present
• It does raise awareness for the concept of urine diversion, which
is good
Some people, who could be called “ecosan purists” would not approve of this
type of toilet – they prefer the waterless toilet types! But one shouldn’t think in
exclusive terms.
Course 1 Unit 3
Vacuum toilets (1/3)
• Usually without urine diversion (but
can also be with UD)
• Very low amount of flush water
– Typically uses only 1 L per flush
(compared to 9 L per flush for
conventional toilet)
– Results in the production of
concentrated “blackwater”
• This blackwater is usually treated
with anaerobic digestion (ongoing
research projects on this topic at
Wageningen University, The
Vacuum toilets (2/3)
Vacuum toilet (Roediger)
Vacuum urinal (Roediger)
KfW building, Frankfurt, Oct.
Vacuum toilets (3/3)
Vacuum pump station (Roediger)
in basement of KfW building,
Frankfurt, Oct. 2006
(with Arno Rosemarin, Swedish
ecosan specialist at EocsanRes
Programme of Stockholm
Environment Institute)
Example for vacuum toilet
and blackwater treatment
At Sneek (the Netherlands),
blackwater from vacuum toilets in 80
houses is treated in anaerobic
digesters (see also Course 2 Unit 4
“Introduction to anaerobic digestion
Blackwater production: 5.6 L/cap/d (1
L water per toilet flush)
Bruno Meulman
Fresh blackwater (not very black!)
Foldable UDD toilet
“Rescue 25 Camping” model from
Swedish company Separett
Price could be as low as € 15 for a
basic version, which could be
applied for emergency sanitation
(need to get aid agencies interested
in this option)
Tchobanoglous, G., Burton, F.L., Stensel, H.D.
(2003) Wastewater Engineering, Treatment and
Reuse, Metcalf & Eddy, Inc., McGraw-Hill, 4th
edition. Good book on conventional wastewater