Ever scratched your head trying to find safe excreta disposal solutions for pour flush latrines in congested urban slums, remote locations, high water tables, rocky ground and no-network areas? Well, this webinar could have the answers you've been looking for.
The worm based sanitation project in Monrovia was designed by Oxfam and inspired by the Biofil (from Ghana) and Tiger Toilet systems. This novel system aims to tackle the challenges of excreta disposal where de-sludging is not possible and was designed for pour flush latrines (where waste is disposed of directly into an above ground concrete chamber). The worms live in a bedding material (coconut fibre which has been soaked for 24 hours in water) and eat the waste flushed into the chamber. Excreta are deposited on this bedding material whilst the liquid is filtered through a media of gravel, charcoal and sand. The effluent produced is collected in an external sump, which is then emptied by the householder.
After 3 years there is virtually no waste to remove from the chamber as the worms eat and excrete nominal amounts. This approach of course requires community engagement, understanding and pro-activeness before, during and after the installation of the system.
For both the presentation and the audio, visit our YouTube channel: https://youtu.be/j04tGVNP6Xg
2. AGENDA
Introductions & general housekeeping (5 mins)
Background on how it all started (5 mins)
Presentation – David Watako (WASH Specialist, Oxfam Liberia)
& Mougabe Koslengar (WASH Specialist, UNICEF Burkina Faso)
(20 mins)
Q&A open discussion – Moderator Jola Miziniak(20 mins)
Wrap up on tiger worms & whats new in excreta management -
Andy Bastable (10 mins)
3. TECHNICAL OVERVIEW AND GROUNDRULES
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5. The problem
The sanitation coverage in Monrovia is very low 18% JMP 2012.
Most of the people live in the slum areas with not enough resources and spacing to
build a toilet.
The geographical and hydrogeology of some places contribute greatly to the
difficulties faced by communities in constructing toilets.
Septic tank system is widely accepted in Monrovia but not everyone can afford it
due to its very high cost; the alternative is usually to build a cesspool.
Inability to afford the septic tank and to build their own toilets due to the lack of
spacing and funds etc,implies that open defecation, flying toilets, and hanging
toilets along the riverbanks remains the common coping mechanisms for excreta
disposal in the slum areas.
This is the number one contributor to health problems in the slum communities of
Monrovia. The stakes are even higher with the recent EVD outbreak.
6. Prof. David & mougabe
How it works in theory and lessons from the field
7. The Worm Concept
The tiger toilet is a flushing system that uses worms to transform faecal matter
into vermicompost. A tiger toilet consists of a pour flush latrine connected
to a concrete chamber (biodigester)
The biodigester contains worms, which live in a bedding material and feed off
the feaces, breaking it down. Effluent from this layer filters through a layer of
sand, gravel and charcoal .
The effluent produced is connected to either an infiltration gallery or collected in
an external sump (emptied by the householder and could even be used as
fertiliser).
The action of the tiger worms significantly reduces the build-up of solids in the
system, although there is a gradual build up of vermicompost, requiring periodic
emptying of the biodigester
8. The Worm Concept
The worms in the biodigester are African Night Crawler (Eudrilus Eugeniae), an
earthworm native to tropical West Africa, which is typically used in
vermicomposting systems.
Vermicompost is produced through the worms’ ingestion, digestion and
absorption (Viljoen, et al 1992) of organic waste and the subsequent excretions
(the digester is a mesophilic systems (Chaudhuri, et al 2009).
The process reduces the volume of feaces between 70 to 80 percent. Eudrilus
Eugeniae can survive feeding solely on feaces and does not require other
inputs (unlike worms found in composting toilets that require a proportion of
organic matter Reference).
Tiger worms reach maximum weight (0.45 g to 1.26 g [Vijaya, 2012), length
(10-12cm) and segments in 15 to 20 weeks (Rodriguez &Lapeire, 1992).
9. The process
1
• Understanding the process
2
• Meeting with Beneficiaries
3
• Design and construction (BoQ and Recruitment)
5
• Monitoring (testing and documentation)
12. Steps of Construction
1-Assessment
Available space for construction
of the Bio digester and the
installation of the commode toilet
Available space for garden
Existing structures condition
(Floor level and plumbing
connection)
13. Steps of Construction
Bio digester Foundation
Size: 1.5m*1.3m
Concrete ratio 1:2:3
Bio digester
Size: 1.m*1.m*1M
Concrete ratio 1:2:3
14. Steps of Construction
Top slab
Size: 1.5m*1.3m*0.05
Concrete ratio 1:2:3
Porous slab
Size: 1.2m*1m*0.05M
Concrete ratio 1:3
25. Monitoring BD functionality & Effluent quality
Parameter
Flushing system (comment on where the waste is being doped and any leakage on the system etc)
Worm (how healthy are they, note their movements scrolling etc..)
Faecal material: Estimate the Waste accumulation (g)
Faecal material: Estimate the Waste degradation (g)
Filtration system (any water standing on the top of the filtration layer, quantity of water in the
transition chamber, drainage to the effluent collector etc)
Temperature (°C) norms: 60-80° F(15,5°C-26,6°C)
TU (NTU)
pH
BOD/COD (mg/l)<200mg/l/400mg/l
Colour/odour
E.coli (FCU/100ml) 5000/100ml
Use of the effluent
26. To do
Cleaning around the Toilet (outside): Always keeps the BD surrounding clean, clean 1/week if necessary. Elevate the BD
surrounding to avoid flooding.
Cleaning for the Toilet (inside): Use clean water to wash the bowl, keep always spray the inside toilet with
insecticide/fresher
Material to use for posterior cleaning: Always use the soft tissue or water (do not use hard paper or plastic). Never drop
bottles, plastics and any inorganic matter in the toilets
Effluent removal (frequency) 1/weeks
Effluent disposal: use the effluent to water gardens, banana trees etc
Gardening techniques: use off ditches (roll type) does not directly waste the effluent on the corps.
Rodent/Flies/odour control Use of insecticide to fumigate around the BD (outside) and spray the inside toilet all of
the time. Always keep the surrounding of the BD clean clear
Waste removal: Remove the digested waste (black soil) after you notice that the bio digester is getting
fill up. Use a shovel or any material to take the black soil out. Change the coconut coir
and add some worms if you have removed some with the black soil (usually the worm
move to the filtration layer when you manipulating)
Waste disposal (ditto as effluent)
Coconut and Worm replacement: add some after waste removal
General Control check: Observation inside the BD
(frequency):
1 every 3 months (observe the waste commutation, worms heath condition and
number). Call the technician if you notify water standing in the bio digester or lot off
fresh and less /no worms)
Call technicians if: physical Damage on the BD or effluent, commode not flushing,
O&M hints
27. ..
.
Dysfunction alert and
troubleshoots(community)
Diagnostic Action
No effluent coming out Call the technician to do general checking
Invasion by ants Fumigate the outside of the Toilets with
deltametrin 1%(ants powder)
Water standing in the BD Remove the waste and replace the filtration
layers (to be done by the technician)
Flooding (effluent collector) Raise the protection wall
Odour/flies -Call the technician to do general checking
and place properly the cover slab if required.
-Spray the inside toilet (insecticide and
fresher)
Toilet not flushing -Call the technician to check the flushing
system
No digestion (observed during the general
control chek)
Call technician (cheek the worms and add
worms if required
Effluent collector leaking Replace the drum/ revert to infiltration trench
To call technician, Use: +231(0)886243145/+231 (0) 5901750
28. LESSON LEARNED
CHALLENGES
Beneficiaries participation
Space for gardening
Effluent disposal during flooding
Cultural barriers/Ebola and
disinfection
MITIGATION
MoU, 25% participation
Collective garden
Drain the effluent through the soil.
29. Learning points
Worms
How they work?
How much can they eat?
What do they do?
How fast do they grow?
What types of worms can
you use?
What we know
E. Eugenia, is locally available and is very
similar to E.Fetida
2Kg of E.Eugenia/m2 (theory)
Feeding rate(kg feed/kg worms: ?????(0.8-
2Kg theory)
Decaying process slow (not visible before 15
days)
Temperature (less 30Degre) and Humidity
(80%) are very important to worms
Effluent collection:1 /week
Bedding – coconut fibre, onion bag
Effluent quality – better than septic tank (
Configuration – bedding, drainage, sump
30. THANKYOU!
For More information contact:
David Watako dwatako@oxfam.org.uk
Mougabe Koslengar mkoslengar@unicef.org
Andy Bastable abastable@oxfam.org.uk
Claire Furlong c.furlong@iboro.ac.uk