tiger worm toilets (oxfam public health engineering webinar)
TRANSCRIPT
Tiger Worm Toilets
Friday 31/07/2015
WASH Webinar 01
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)
TECHNICAL OVERVIEW AND GROUNDRULESYou can either send in your questions beforehand
OR
As you watch, please write your questions and observations in the chat box to help us when we come to the Discussion.
OR
You can press the button to raise your hand during the discussion. Please wait for us to say your name before you press talk to speak
How it all started...
Claire Furlong
The problemThe 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.
Prof. David & mougabe
How it works in theory and lessons from the field
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
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).
The process
1
•Understanding the process
2
•Meeting with Beneficiaries
3
•Design and construction (BoQ and Recruitment)
5
•Monitoring (testing and documentation)
DESIGN
BOQItem Description Qty Unit (USD) Unit cost (USD) Total
1 Cement 7 50kg 9 632 Sand 1 m3 30 303 Crushed rocks 1/4" 0.3 m3 30 94 Poor flush squate/commode 1 pc 60 606 Mesh Wire (large roll) 4 m2 5 207 Onion bags 1.2 m² 0.5 0.68 Fishing line 2 rl 1 29 Plumbing putty 0.25 can 5 1.25
10PVC glue 0.5 can 5 2.511 4" PVC pipe 0.5 pc of 6m 18 9124" PVC elbow 2 pc 3 6
13Floor tiles (12"X12"ceremic) 1 ctn (11 pc) 15 1514Steel rods (1/4") 0.2 pc of 12m 10 215Coconut shred 0.5 wb 10 5162" PVC Elbow 2 pc 3 617PVC Pipe 2" 0.5 pc of 6m 8 419White cement 0.3 50kg 20 6214" PVC coupling 1 pc 3 3224" PVC Tee 1 pc 4 4232" PVC Tee 1 pc 3 324Reducer PVC 4''X2'' 1 pc 3 325Nail 2" 1.5 pck 2 326Timber (2 x 4x 14) 2 6m 6 1227 6" cement block 80 pc 0.56 44.828 Empty drum (plastic) 1 pc 30 3029 Charcoal 1 wb 4 430 worms 2.4 kg 7 16.8
Sub-Total 364.95
Workmanship @ 25% x material cost 1 toilet 91.2375 91.2375
Grand Total 456.1875
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)
Steps of Construction
Bio digester FoundationSize: 1.5m*1.3mConcrete ratio 1:2:3
Bio digester Size: 1.m*1.m*1MConcrete ratio 1:2:3
Steps of Construction
Top slabSize: 1.5m*1.3m*0.05Concrete ratio 1:2:3
Porous slabSize: 1.2m*1m*0.05MConcrete ratio 1:3
Steps of Construction
Effluent collector connectionInstallation of the filtration layers-Sand:15cm-Charcoal 5cm
Steps of Construction
Installation of the filtration layers
-Gravel 10cm
Positioning Onion bag
Steps of Construction
Tiger worm (Eishenia. foetida) Eudrilus engeniae
Steps of Construction
2KG of E.eugeniae
Steps of Construction
Adding coconut fibreAdding worms
Steps of Construction
Inside view: Regular commodeInside view: squat type
Steps of Construction
Finished systems
Capacity building
Transferring knowledge
ADDED VALUES
Empower womenContribute to livelihoods
Monitoring Effluent
Testing TurbidityTesting Electrical conductivity/total dissolved solids
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
To doCleaning 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
..
.
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
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.
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
THANK YOU! For More information contact:
David Watako [email protected]
Mougabe Koslengar [email protected]
Andy Bastable [email protected]
Claire Furlong [email protected]