According to the WHO’s Factsheet No. 330 of April 2013, each year diarrhea kills around 760,000 children under five. Unsafe drinking water, dismal sanitation and poor hygiene are the culprits that play their role in causing diarrhea; with poor sanitation as the main factor. Poor sanitation also contributes to children’s stunted growth, and decreased cognitive development.

Sanitation in rural areas of the developing countries is generally poor. There is also lack of political will to improve sanitation in rural areas. Even in places where there is some degree of advocacy, sanitation marketing, and prevalence of enabling environment, the improvement is just marginal.

Given the fact that the sanitation in rural areas is poor, one shudders to think what would be the level of sanitation in floating villages – yes, the floating villages!! In Cambodia, floating villages can be found along the Tonle Sap Lake. Floating villages also exist in Indonesia, Myanmar, Malaysia and Nigeria.

For meeting their toilet needs, the people living in the floating villages relieve themselves in isolated spots, or at night, they simply do their business on the side of their floating house, with contents dropping in water – as simple as that! This creates unhygienic conditions, since the same water is also used for cooking.

A social Cambodia-based concern, called Wetland Work, has developed an innovative solution, called the HandyPod. WaterAid is also partnering with the project. The system is rather simple: The contents from the improvised toilet go a drum, where the contents are digested anaerobically. The contents then flow to the floating HandyPod, where the roots of water hyacinths further break down the contents. The final effluent is discharged into the water.

The attachments, plus a image, further explain the project.

F H Mughal

There is forecast of heavy rains in the coming weeks, in Pakistan. The flood forecast center has warned of very active monsoon season ahead. Floods have already affected low-lying areas, and the Indus River is running in medium floods, which would be converted to high floods, probably next week.

Like the previous floods, it is expected that the sanitation facilities (principally, the toilets) would be rendered dysfunctional. Other than the lip-service, no concrete measures were taken to adapt sanitation to high floods, or build resilience.

With that background, a recent WaterAid blog (www.wateraid.org/au/news/news/the-handyp...munities-in-cambodia) makes an interesting reading. James Wicken, who is WaterAid's Country Representative for Cambodia, talks of the sanitation for floating communities in Cambodia. Called the HandyPot, and resembling a floating garden, or a child's paddling pool with a garden in it, the HandyPot is a man-made wetland filled with water hyacinths.

According to the blog, in the system, a normal porcelain squat toilet on the back of a floating house connects to a drum where the anaerobic (oxygen-less) processes take place. From here, the waste passes through to the HandyPod floating nearby, where the roots of water hyacinths further break down the waste before it passes into the lake. The researchers regularly collect water samples in the area around the pods, to ensure the quality conforms to Cambodian standards.

While the WaterAid is working on its scale-up, it would be interesting me see the results of large-scale implementation, especially its maintenance after long period of its operation. There is a risk of contamination, if the system is overloaded, or the people do not maintain it properly, or the users simply become careless.

F H Mughal

Dear Taber,
Thanks for this clarification, very interesting work.

The above mentioned presentation ("A constructed wetland system for flood resilient sanitation") from John Allen is now also available as video here:



Or scrol to time 34:01 in this video:



The all important question and answer session start at time 43:22.
Enjoy.

Regards,
Elisabeth

Hi, Elizabeth --

The picture you attached (Constructed Wetland System) is for our land based treatment design and is most appropriate for flood prone areas, different from floating households in open water areas. In fact, as described below, the design has changed to use only 'traditional' cement septic rings.

Yes, regarding FLOATING community sanitation -- 'floating wetland' is more descriptive than 'Pod' but does not have the branding potential as a name. In fact, in Cambodia, Wetlands Work! Ltd. is asking users to come up with a Khmer name as part of a lottery to 'win a "HandyPod"'. The HandyPod, developed over 4 years in a floating community, has been in use in its "final" product form for less than one year. During our present sanitation marketing scale-up process for several thousand HandyPods in 10+ communities, we expect new materials will be sourced over time, including EPDM liner currently unavailable in Cambodia, and cost elements and design features will change to reach an 'appropriate' price point. Maintaining quality, including materials that last at least 4 years, is an important sustainability issue to impart on local businesses that make and supply HandyPods. All items we use have a very long life with the possible exception of the PVC liner material. It is shaded by plants and it can be double lined where sun exposure may occur, but will it last 4 or more years in the very extreme conditions? We do not know; substitution with EPDM liner -currently not sourced in Cambodia- may be a reasonable development. It's strong, flexible and very resistant to UV photo-degradation.

Forgive the confusion: WW! now has two treatment systems for sanitation in challenging environments (SCE). At the 2015 FSM3 Hanoi conference, we presented a new LAND BASED flood prone/high groundwater treatment system for households. This system is being built as a pilot project for 46 households in two flood prone communities in Cambodia. WW! will monitor treatment efficiency and behaviour change issues starting in May 2015.

This flood prone system has three stages of treatment. Each additional pour flush moves the waste by gravity flow from primary treatment in the septic container, to secondary treatment in a planted gravel bed, and then to tertiary treatment in a polishing pond. Our field tested design showed six log order cfu of E. coli reduction AFTER first stage treatment in the septic container. We have radically re-designed this from the picture included (Constructed Wetlands System), as we are now using only standard cement rings in sequence for each stage. It's cheaper, simpler, faster, more intuitive for builders, and more easily replicable. (And, as commented upon, less susceptible to cracks in a clay berm.) We are pleased with the possibilities for this design and hope we can train people and partners and license its usage widely.

WW!'s flood prone treatment systems are designed to serve one, two or three households, each house having about 6 people. Each individual house has its own septic container underneath a raised latrine, and each treatment system has differently sized 2nd and 3rd stage treatment systems according to the number of houses being served.

In one of the villages we are testing a single treatment system that is different from the rest, having a floating Pod tethered by poles that allows the Pod to rise with very high flood events. This is experimental and applicable for houses built on stilts beside a sloped flood way. This 3rd stage 'floating Pod' is conceptually similar to the picture with poles -- Constructed Wetlands System -- and this rising 'Pod' is preceded by 1st and 2nd stage treatment using cement containment rings. Best ways, Taber

Dear Taber,

Thanks for this update.
I am a little bit confused, is this presentation from the FSM3 conference about the same system?:

A constructed wetland system for flood resilient sanitation: John Allen, Wetlands Work, Royal University of Agriculture, Dongkor District, Cambodia

www.susana.org/images/documents/07-cap-d...-1/2-1-4-3-Allen.pdf

I have to say that the term "pod" has always confused me and "floating wetland" is much better in my view.
This picture from the presentation made it finally clear to me what it is:


I wonder though about the longer term stability of such a system, as you could get cracks in your "boat" type structure which presumably lead to a poorer performance of this floating constructed wetland.

How long as the longest one been in operation for so far?

Regards,
Elisabeth

Thanks, Mughal for mentioning this article about our work in Cambodia.

Let me give you all a little update on our project since my last post one year ago:

Wetlands Work!’s HandyPod is now a product for floating household sanitation. It reduces wastewater E. coli by 5 log order and meets all criteria for desirability amongst floating householders. It has a Cambodian material cost of approximately USD $35, though the cost to a consumer has yet to develop in a market-based context.

Our work has now moved from the final product stage to the marketing issues of creating a local/regional entrepreneurial supply and then developing the demand by poor floating householders to pay for the product through CLTS, etc. Sanitation marketing for floating communities has never been done before and we expect this will be a 2-steps forward, 1-step backward process. It will take several years, too, to be done at scale. This work is supported by a grant to WaterAid Cambodia from The Canadian Grand Challenges Program for Stars in Public Health, enabling Wetlands Work! Ltd. to partner with WaterAid and further develop the sanitation marketing program.

Additionally, WW! has developed a 3-stage treatment system for households in flood prone/high groundwater areas that is being piloted at 46 homes in Cambodia. We are excited about this recent work, and hope to make it affordable to the poor householders who live on such marginal lands.

Wetlands Work!’s designs for both floating and flood prone/high groundwater areas are relevant to the rural-to-urban population explosion scenario described as a mega-trend for major cities in East, South and Southeast Asia, Africa and South America. Favelas and shanty villages can be expected to develop on such land and water areas; it's the only alternative for landless poor migrants. There's no preparation or zoning thought being given for such potential settlements. Perhaps, WW! can provide a template for the sanitation element.

NB: Sanitation in Challenging Environments (SCE) has received little attention until recently. In Cambodia, Engineers Without Borders has convened groups interested in this area three times since August 2014. These SCE interests are now working to develop definitions, set standards for comparison and evaluation, and promote the monitoring and evaluation of SCE projects. These are very worthy efforts that should receive attention in the broader sanitation community.

Thank you.

Taber Hand
Director, Wetlands Work! Limited
Phnom Penh
wetlandswork.com

Under E-Source Sanitation News of 24 Dec 2014, Cor Dietvorst has disseminated interesting news of floating toilets (www.npr.org/blogs/goatsandsoda/2014/12/2...elves-grow-on-a-lake)

According the news, a group of engineers in Cambodia wanted to solve the problem of the floating villages of Tonle Sap Lake, the largest freshwater lake in Southeast Asia.

To help clean the lake's water, engineers in Phnom Penh developed plant-based purifiers, called Handy Pods. The pods are essentially little kayaks filled with plants. They float under the latrine of a river house and decontaminate the water that flows out.

Here's how it works. When a person uses the latrine, the wastewater flows into an expandable bag, called a digester. A microbial soup of bacteria and fungi inside the digester breaks down the organic sludge into gases, such as carbon dioxide, ammonia and hydrogen.

Some microbes in the waste survive that first step, but then they're washed into a pod filled with water hyacinth. The hyacinth roots have a large surface area to which the remaining bacteria stick. The water that runs off the roots into the lake is clean enough to play and swim in. The water is not safe for drinking.

During a pilot project in 2013, pods were given to 35 houses in a village on Tonle Sap Lake. The pods reduced E. coli in the ambient water by 50 per cent. In lab tests, pods reduced E. coli by more than 99 per cent.

F H Mughal

Re: Up-date
Wastewater Treatment w/ 'HandyPod'

Dear Naomi and SuSanA,

First a quick response to Naomi's questions, followed by our up-date.
1. Workshop trainings? -- No workshop trainings. We will use a different strategy to replicate Pods through sanitation marketing and CLTS programs. Given funding, this will take place in 10 pilot floating villages. As there never has been a sanitation alternative in floating communities before, we will be on new and interesting 'ground' with such a program.
2. Menstruation and school-based practices? -- This is not a subject we have surveyed. WW! has been asked to propose sanitation treatment for a number of floating schools. If funded, we will design into the privacy area for the girls' latrines a place for such maintenance. This would include a cloth washing area.

Up-date info
Dear Naomi and SuSanA Forum -

Re: Wastewater Treatment for Floating Communities – The HandyPod

Wetlands Work!’s “Pod” is in the final stages of ‘product development’. The Phase I Gates grant concluded last April 2013 and now -11 months after our initial intervention of 34 Pods in one village- we can make the following assessments:

1. People want the Pods. They noticed fewer feces in the water in the village. There is more privacy (dignity and security?) for women as OFD from a boat, etc., is no longer necessary.
2. After Pods were installed there appears to be a lower concentration of E. coli in the intervention village than in the control but this was not statistically significant likely for reasons 3B and 7, below.
3. Pods used in the 1st intervention need a redesign, which we are planning now. Issues were:
A --odor, visual feces and splash-back at the squatting bucket—now taken care of using a water trap.
B –structural redesign such that in low water season the floating house does not crush the anaerobic Pod portion –now taken care of by substituting this treatment stage with a 40+ liter plastic container that is positioned differently.
C –material deterioration – now resolved with use of HDPE geomembrane[/li]

4. Salt tracer research and bacterial analyses have demonstrated the new Pod’s improved performance with treatment efficiencies of up to 99.9999% pathogen reduction (E. coli), and consistent reductions of 4 to 5 log orders, when subjected to the sewage from a 6-person family.
5. Villager feedback is very sensitive to who is asking the questions, and must be done by an outside professional.
6. The material cost of a Pod is ~$20-$25.
7. The presence of floating pigpens in the village –which have not received waste treatment- means our Pods’ impact on ambient water quality is less than desired; this high potential disease vector source needs to be treated with Pod-like systems, too. Pig feces and children in the same water do not mix well.
8. Children’s frequency of diarrhea was less during the time of poorest water quality, in the low water season, because they swim less as the water is very shallow, turbid and fetid. Diarrhea is highest during the mid-flood and recession stage in the Lake when E. coli is high but water appears more attractive to swim in. (Difference between seasonal high and low water in Tonle Sap Lake is 8.5 meters, or 27.5+ feet.)

Due to the structural problems noted in 3B above, of 34 Pods installed, 12 remain functional. Using the newly designed Pod, a total re-intervention in the same village is planned.

WW! continues to monitor water quality and child health (weekly) in both control and intervention villages. This data is a significant quantitative resource and will be used to assess the impact of our second long-lasting full-village intervention on water quality and health.

Given success in the second full-village intervention, WW! will initiate sanitation marketing (SanMark) and CLTS (community-led total sanitation) in a broad pilot program in 10 floating villages on Tonle Sap Lake, Cambodia. Until now, no appropriate and sustainable means to treat human waste from floating households has ever been created for the very poor living in challenging waterborne environments. We believe the HandyPod and it’s innovative SanMark replication strategy is poised to provide a practical solution.

WW! is also designing Pod treatment for seasonally flooded homes on a floodplain, for stilted houses, and for flood emergency sanitation relief.

Thank you, SuSanA, for the opportunity to present this information.
Taber Hand, Ph.D.
Director, Wetlands Work!

Dear Taber,

Hope both you and the project are doing well!

It is about half a year that the pods are now floating on the lake.

This makes me curious about the development of the project.

You mentioned that you intend to give workshop trainings to encourage entrepreneurial pod-making in the floating communities. Have any workshops already taken place? How was the response by the village community – is there interest and potential to start up a pod-making enterprise?

Menstruation is part of most women’s life and is often seen as a time of discomfort, among others due to lack of privacy for changing sanitary products and for adequate menstrual hygiene practice. I was wondering whether you picked up menstruation as a topic when doing research; do you know how menstrual hygiene is practiced within the floating communities? And have you thought about adapting the pod toilet system to these needs?
Best regards,

Naomi

Thank you for your questions, Dorothee.

In the treatment village 150 people are living in 34 floating houses including 47 children. There are 68 children in the control village of 205 people. In both treatment and control villages, we weekly record gastro-intestinal health for each child 10 years and younger, with our target population being 0-5 year olds.

Each house has a Pod sequestering and significantly improving the wastewater’s concentration of pathogens, as measured by E. coli and total coliform. On average our treatment Pods reduce E. coli 2 to 3 log orders in concentration before diffusing into the ambient water. With ongoing tracer tests we believe this efficiency can be improved.
 Soon we will have capacity to test for other pathogens, including viruses, protozoans, helminth eggs and other bacterial species. The ambient village waters are tested monthly in peak flood season and twice monthly during low water season.


Can you already give any information on what level of improvement in the gastro-intestinal health among the child population was possible with this technology?

It is too soon to tell what the health benefits are. The adult villagers say they do not see floating feces any more, so that’s a positive step of basic awareness. It appears that the peak periods of diarreah are the two 3-3.5 month periods of rising and falling water (the lake water pulses 30 feet in depth between dry and wet season). This corresponds to water that has significant fecal contamination and in which the children actively swim, instead of the fetid low water season which was our anticipated focus period. During the high water period when the lake is basically an inland ocean 4-5 times the size of its dry season area, there appears to be less diarreah perhaps due to physical dilution and assimilation. During the low water period the children are rarely swimming as the water is hot, very turbid and contains itchy surface micro-algae; as well, children have access to land in the floodplain forest at this time.

Did you also monitor water quality (and what were the results)?

Four water samples are taken in transect through each village bi-monthly. A single transect’s E. coli numbers are averaged for one datum point. Concentrations range seasonally from 3,000 to 11,000 cfu/100 ml in low water to 350 to 3,000 cfu/100 ml in high water. We also monitor turbidity, temperature and depth. (As this is in part a child health impact project, we are not concerned with the nitrogen and phosphate contribution from wastewater, which is dwarfed by the agricultural contributions. Nevertheless, the surface micro-algae that appears in the low water phase is to some degree supported by the human waste's N and P.)


One last question – you mention that women particularly appreciate the floating toilets (instead of open field defecation): What does the user interface look like?

The latrine has visual privacy from the water. This privacy screen is an additional expense (~$15) with a wood frame and tarp material that will in time be weathered useless. The latrine itself is simply two wooden planks to squat on above a 20 liter bottomless paint bucket tightly fitted into the anaerobic portion of the Pod. The bucket has a tethered lid to be capped when not in use. In our developing SanMark program we will offer the option of a latrine with a more traditional pan that has a water trap and is sealed to prevent odor and back-splash when in use.


And another issues often concerning women –what maintenance is needed and what are the associated costs?

The only obvious maintenance is to add water into the bucket as part of the personal washing process and to cap the bucket with its lid. The aerobic Pod may need to be refilled with hyacinth after major storm events. We are concerned about the UV degradation on the Pod sides and have double-layered these areas with material, yet are finding that the significant growth of hyacinth completely shades these areas. We are experimenting with other suitable materials, as well.
The Pod costs about $15 dollars and can be made by anyone with locally available materials. The privacy screen is an additional expense (~$15) for a wood frame and tarp material. In time the privacy tarp will be weathered useless; we expect people will be motivated to replace it with wood or another suitable material.

Dear Taber

Thank you for the introduction of your project and the pictures.

Impressive: you have already equipped a whole floating village with the the Pod Toilets!
How many prototypes did you have to construct to go to such a scale? (How many inhabitants has the community by the way and how many toilets were installed?

Can you already give any information on what level of improvement in the gastro-intestinal health among the child population was possible with this technology? Did you also monitor water quality (and what were the results)?

And one last question – because I am a women : ) and you mention that women particularly appreciate the floating toilets (instead of open field defecation): How does the user interface look like?
And another issues often concerning women – what maintenance is needed and what are the associated costs?

Kind regards,

Dorothee

Floating Treatment Pods for Lake Communities in Asia

Name of lead organization: Wetland Works! Ltd, Phnom Penh, Cambodia
Primary contact at lead organization: Taber Hand: This email address is being protected from spambots. You need JavaScript enabled to view it.
Grantee location: Cambodia
Developing country where the research is being implemented: Cambodia (Tonle Sap Lake) and Burma (Lake Inle)

Short description of the project:
The socio-entrepreneurial start-up Wetlands Work! received a grant in Round 7 of the Bill and Melinda Gates Grand Challenges Exploration program. WW! has developed an individual household wastewater treatment system that uses floating “Pods” - similar in appearance to children’s wading pools - that are positioned directly under the toilets of houseboats occupied by low-income fishing families. Similar to aquatic mesocosms, the Pods are filled with floating plants, and the bacteria that reside on the plant roots are capable of breaking down contaminants and making the water significantly cleaner. Presently, Pods are installed throughout an entire floating community and data on water quality (indicator organisms) and diarrheal incidence (children <10 yrs.) are monitored and compared to a control village without pod intervention.

Goal(s):
The goal of this project is to design and field-test at village scale a simple cost-effective wastewater treatment system for floating communities in Southeast Asia. Using the microbial activity on aquatic plant roots within floating “Pods” installed under the toilet of houseboats, the project seeks to improve ambient water quality (in terms of reducing microorganisms of fecal origin) and demonstrate improved gastro-intestinal health among the child population of an entire village. To promote replication of the treatment system, a supportive regional and community planning program will be developed to improve health through improved ambient water quality and workshop training will be used to encourage entrepreneurial Pod-making in the floating communities.

Objectives (or activities or key research components):
1) Floating “Pods”: developed and refined Pod structure containing common water hyacinth (Eichhornia crassipes) and associated mesocosm biota constructed from widely used tarpaulin and other locally available materials. The volume of a single Pod is ~236 litres (1 x 1.5 x 0.4 m). Two connected Pods are used per household. The first, which is positioned directly under the toilet, covered and predominantly anaerobic, is linked through a small opening to a second Pod, predominantly aerobic and containing plants. This set-up eliminates odor and increases treatment capacity.
2) Pod tests: demonstrated the ability of the single aerobic Pod to significantly reduce E. coli (an indicator bacterium) levels under controlled conditions by 3 log orders in a 24-hr period, for example from 6.7 to 3.9 log reduction of E. coli. Pods were filled with clean water and hyacinth (~3.5 kg). Sewage or raw feces were added and E. coli measured in water samples.
Pod tests on lake: A tracer study will be used to determine most efficient retention time and flow between double Pods and out flow to ambient water.
Pilot Pod village tests: Single Pod tested 1+ year at a floating research station and then for 4 months at a villager’s house, followed by village-wide deployment of double Pods since January 1, 2013.
Two villages have been selected, with one acting as a no-intervention control, while in the second treatment Pods are widely adopted in all but three houses. There are approximately forty households in one, fifty in the other at similar income levels. Each family has between 4 to 6 people.
A weekly survey is used to gauge the health of 0-10 year olds (our target group is 0-5 yr olds) in the villages using a simple questionnaire on gastrointestinal symptoms and three photos from the Bristol stool test.
After 18+ months of Pod usage, health and water quality data collected over the course of Pod implementation in the two villages will be statistically assessed.
3) Field-testing on the village scale (40 households, 37 Pods, 198 people): Observing and addressing usefulness, behavioural adaptation and maintenance issues, as well as optimising Pod size to ensure sufficient treatment capacity for larger households of 7 or more, including schoolhouse. Further, testing locally available materials (e.g. bamboo baskets) to adapt in Pod construction.
4) Field-testing in Burma: In addition to the floating villages in Cambodia, a variant treatment Pod is being designed for pilot introduction in two stilted home communities (~50 Pods each, total ~460 people) living on Lake Inle, Burma, which face similar challenges in sanitation. The administrative framework and MOU are in place, and we are currently awaiting funding.

Start and end date: October 2011 to 30 April 2013

Grant type: Grand Challenges Exploration, Round 7
Funding for this research currently ongoing: Seeking funding beyond April 2013.
Research or implementation partners: Conservation International in Cambodia and Inle Lake and Watershed Development Association and Institute of International Development in Burma

Current state of affaires:
Field-testing of double Pods on the village scale is now being conducted; we plan to continue monitoring child health including weekly diarreah events, weight (monthly) and height (2x yearly); bacterial water quality; water depth and turbidity; number of pigs; and general behavior change issues until June 2014.

Biggest successes so far:

• The design works. Significant iterations of design and research have led to a successful treatment system for the reduction of microorganisms of fecal origin in ambient village waters.
• The Pod is affordable (current model: $20, including platform), user-friendly, produced locally with locally available materials and only needs low maintenance such as adding plants after very intense storms.
• The villagers want the Pods, in part for the privacy screens that are built with the Pod.
• Women appreciate the easy toilet access and privacy and, apparently, do not have the personal concerns associated with open field defecation.

Main challenges / frustration:

• Development of an appropriate community-led total sanitation (CLTS) process for floating communities using the Pod treatment system is just beginning, as no treatment method has ever been implemented at this scale before.
• Challenge in the field-testing program to ensure accurate weekly user feedback from children.
• Villagers want to be provided medicine for diarrhea; we will organize community meetings with a nurse to explain potential health benefits of Pods and to distribute oral rehydration solution (ORS) packets.
• Challenge to address fecal contamination of ambient waters from floating pig styes located along-side houses.
• Coordination and communication with well-intentioned NGOs who want to work in our research villages to provide WASH programs or ORS with zinc which may significantly afffect our longitudinal data and assessment.
• Challenge to find alternative very long-lasting design materials ( e.g., replacing the tarp with bamboo)

Links, further readings, etc:
Presentation on the 2nd Fecal Sludge Management Conference 2013 in Durban: www.susana.org/en/resources/library/details/1756

Video from this presentation:


Grantee webpage: wetlandsworkllc.wordpress.com/2012/12/12/handy-pods/


Double Pod sketch with plants and latrine bucket, and cut-away showing bottle flotation.



Double Pod without plants and latrine bucket for input, as shown above. Anaerobic Pod is attached to aerobic hyacinth Pod with small flow space between.



Pods and privacy screens (blue) in treatment village, Akul, Tonle Sap Lake, Cambodia