SuSanA - Forum Kunena Site Syndication Sat, 23 May 2015 02:43:21 +0000 Kunena 1.6 SuSanA - Forum en-gb Re: Introducing Sanitation in Floating Communities - (and Flood prone land based communities) - by: muench 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.

Constructed wetlands, soil filters and infiltration beds Thu, 21 May 2015 14:42:37 +0000
Re: Introducing Sanitation in Floating Communities - (and Flood prone land based communities) - by: Taber
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]]>
Constructed wetlands, soil filters and infiltration beds Mon, 20 Apr 2015 04:52:03 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: Marion
Thanks for your thoughtful answers and advices!

About me, I'm an environmental engineer passionated about ecological sanitation, waste management. I studied at EPFL (Lausanne, Switzerland) and UBC (Vancouver, Canada).
I'm working for SOIL since a year now as the SOIL project coordinator in Cap Haïtien (Haïti). SOIL is working in Haïti in ecological sanitation an since 2006. We provide different services: households toilets, mobile toilets (for events, construction sites), and communal toilets. We have 2 composting sites where we treat all of the wastes generated in our toilets.
We are now focusing to develop our household toilet program: Ekolakay toilets. These are container based households UDD toilets. It's a service meaning our customers pay for the Ekolakay toilet every month (about $5 per month). We currently service 320 Ekolakay toilets and are looking to reach a 1000 by the end of 2015.
(more info-->

Thanks Jeff for the interesting paper, I think biochar could be indeed something to look at (maybe mixed with the growing medium?). I'll dig into it.

Christoph, yes, the septic tank should include storage. We have been using since 2 years and a half a small septic tank. We recently opened the first chamber and we have approximately 90cm of sludges at the bottom.
We are currently looking to get our effluent tested for TSS and BOD. The effluent requirement we are looking to achieve is focused on pathogens reduction: 1-2 log E.Coli reduction. We have about 200 square meters of land available.

Canaday, the current system was not designed for the amount of cleaning water that we are producing now. The septic tank we have is too small and not achieving sufficient pathogens reduction. Our well (hand pump) is located approximately 30m away from our current septic tank, the water-table is 6m below the ground level.
We clean about 600 buckets (5 gallons) and 120 drums (15 gallons) each week.
Regarding our cleaning process, the buckets are first cleaned (with water from our well) with a pressurized water jet, then soaked into a disinfection bath (water+HTH) during 1 minute and then dried by sun exposure during 1 hour. Remember that these buckets are filled with a mix of poop and cover material (sugar cane bagasse and crushed peanut shells) and that poop can stick to the sides of the bucket. We have to disinfect the bucket regarding legislation and also because in a country like Haiti where we are still dealing with a cholera epidemic, typhoid and various other waterborne diseases we need to be sure we are providing 100% safe equipment in our toilets.
Interesting question about if bagasse floats, I'll dig into the reedbed idea!

Carol, the buckets are cleaned, disinfected dried and filled with our cover material (mix of sugar cane residues and peanut shells) that our customer put aside when they put the bucket back into the toilet. For that reason the bucket need to be thoroughly cleaned and disinfected (health and odor issue).

Have a great day!
Constructed wetlands, soil filters and infiltration beds Mon, 16 Mar 2015 20:09:47 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: Carol McCreary
Question: Are these buckets rotated back to households after emptying? If so, couldn't they simply be left to dry a bit and then covered and returned?

Information on Wetlands: Just today there appeared an info-packed article on wetlands."Designing Wetlands to Remove Drugs and Chemical Pollutants" looks at case studies from US wastewater treatment districts. Unfortunately, local jurisdictions have to figure this out because "Currently, there are no U.S. regulations for medical drugs under the Safe Drinking Water Act, and only a few for the residues from consumer products."]]>
Constructed wetlands, soil filters and infiltration beds Mon, 16 Mar 2015 18:57:41 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: canaday
Welcome to the Forum.

Some thoughts and questions:
-- Are there any problems with the current system?
-- How far away are any water wells or streams? (Infiltration may not be a problem.)
-- How are the buckets washed? It seems that this is a lot of water. Maybe the same water could be used all day for the initial rinse to get solids out, then use the same soapy (or sodium hydroxide?) water for washing, and finally some fresh clean water for a final rinse.
-- Do try to avoid toxic chemicals, like chlorine. Hot water might also be a useful option.
-- Does the sugar cane bagasse float or sink easily to separate it from the water? It could be good to have an ABR or a Reedbed (=Planted Drying Bed) for initial removal of the solids. The Reedbed could get dusted with some of the biochar (that Jeff mentioned) or soil, at the end of each day to control flies.

If you find time, please tell us more about yourself, your professional goals, your goals for SOIL and Haiti, etc.

Best wishes,
Chris Canaday]]>
Constructed wetlands, soil filters and infiltration beds Tue, 10 Mar 2015 13:46:08 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: JKMakowka In northern Uganda we also had problems with livestock forcefully entering the wetland to get to the lush green, and while sugarcane also grew well, it is generally not advised to grow crops that can be stolen and consumed raw.
Papyrus or another similar plant that has a non food value is probably best.

A vertical flow "French" system that by design only loaded at intervals should be fine with your usage regime and is usually more effective in treatment due to the aerobic phases. However for best results in pathogen removal you probably need a polishing pond as the last step.]]>
Constructed wetlands, soil filters and infiltration beds Mon, 09 Mar 2015 13:12:21 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: christoph a bit mor information is necessary to assist.
Just some general figures. a) Septic tank should include storage as you have only 3 days of production. Or you go (what I would do) for a sludge minerazlization bed which I would do a bit deeper (to avoid the septic tank). But in order to tell anything it would be necessary to have some basic data - COD, TSS, effluent requirement, space available.

Constructed wetlands, soil filters and infiltration beds Mon, 09 Mar 2015 09:18:40 +0000
Re: Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: JeffHoliman
It is great work that you and SOIL are doing! A couple of components come to mind to help treat your effluent from washing station that has E. coli : biochar and vermicomposting both have been shown to assist with pathogen reduction and bioconversion.

I am attaching a link to paper by Geoff Hill, he did his PhD thesis on composting toilets and demonstrated how worms can be helpful in pathogen reduction processes.

Below is an abstract about utility of biochar.

Water Res. 2014 May 28;61C:288-296. doi: 10.1016/j.watres.2014.05.026. [Epub ahead of print]
Efficacy of biochar to remove Escherichia coli from stormwater under steady and intermittent flow.
Mohanty SK1, Cantrell KB2, Nelson KL3, Boehm AB4.
Author information
Biofilters, designed to facilitate the infiltration of stormwater into soil, are generally ineffective in removing bacteria from stormwater, thereby causing pollution of groundwater and receiving surface waters. The bacterial removal capacity of biofilters has been shown to be lower in the presence of natural organic matter (NOM) and during intermittent infiltration of stormwater. To improve the removal of fecal indicator bacteria (Escherichia coli) under these conditions, we amended sand with 5% (by weight) biochar, a carbonaceous geomedia produced by pyrolysis of biomass, and investigated the removal and remobilization of E. coli. Three types of biochar were used to evaluate the role of biochar properties on the removal. Compared to sand, biochar not only retained up to 3 orders of magnitude more E. coli, but also prevented their mobilization during successive intermittent flows. In the presence of NOM, the removal capacity of biochar was lower, but remained higher than sand alone. The improved retention with the biocharamendment is attributed to an increase in the attachment of E. coli at the primary minimum and to an increase in the water-holding capacity of biochar-amended sand, which renders driving forces such as moving air-water interfaces less effective in detaching bacteria from grain surfaces. Biochars with lower volatile matter and polarity appear to be more effective in removing bacteria from stormwater. Overall, our results suggest that a biocharamendment to biofilter media has the potential to effectively remove bacteria from stormwater.

Kind regards,
Jeff Holiman]]>
Constructed wetlands, soil filters and infiltration beds Sun, 08 Mar 2015 01:23:30 +0000
Constructed wetland to treat cleaning water from ecosan composting toilet (SOIL) poop buckets/drums - by: Marion
We are currently looking to update the water treatment system in our composting site in Norther Haiti (SOIL) to have a septic tank followed by a small subsurface constructed wetland for cleaning water.

We use approximately 7m3 of water every day (monday/tuesday/thursday/friday) to clean the buckets after the wastes (mix of sugarcane by-product and poop) have been dumped in our composting bins.

Right now the cleaning water goes into a septic tank and is then infiltrated in a planted garden (banana and vetiver).

Since we are scaling up, we expect the volume of cleaning water used to increased by around 300% by the end of the year and would like to have a reliable water treatment system. The main objective is to get a significant log reduction of pathogens (especially regarding groundwater protection), and we are looking for the most cost-effective solution.

Does anyone can share similar experience with the design of a system treating cleaning water issued for poop containers?

Also, does anyone would have advice on the following points:

-we are only cleaning bucket in the morning during weekdays meaning that cleaning water is flowing into the septic tank in the morning monday/tuesday/thursday/friday. How would that affect the system?
-we are thinking about lining the SSCW with clay and plant a mix of vetiver/papyrus/sugarcane. Would anyone tested SSCW in Haïti/Dominican Republic, if so what species did you choose?

Thanks and have a great day!]]>
Constructed wetlands, soil filters and infiltration beds Fri, 06 Mar 2015 16:16:20 +0000
Re: Introducing Sanitation in Floating Communities - by: muench
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

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?

Constructed wetlands, soil filters and infiltration beds Fri, 27 Feb 2015 16:16:16 +0000
Introducing Sanitation in Floating Communities - by: Taber
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]]>
Constructed wetlands, soil filters and infiltration beds Mon, 16 Feb 2015 16:44:31 +0000
Floating Toilets - by: F H Mughal

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]]>
Constructed wetlands, soil filters and infiltration beds Wed, 24 Dec 2014 16:57:01 +0000
Re: Nice and quick overview about constructed wetland's historical developments, by David AUSTIN, USA - by: F H Mughal
The attached publication, a joint publication of National Oceanic and Atmospheric Administration, Environmental Protection Agency,Army Corps of Engineers, Fish and Wildlife Service, and
Natural Resources Conservation Service, is a guide on wetlands, and goes on to define the basics, like, what are wetlands, why restoration is necessary, importance of wetlands, etc. It is an interesting publication and, would be useful to the new users in the field.

F H Mughal]]>
Constructed wetlands, soil filters and infiltration beds Sun, 21 Dec 2014 07:17:53 +0000
Nice and quick overview about constructed wetland's historical developments, by David AUSTIN, USA - by: AquaVerde Advanced Treatment Wetlands: A 4 th Generation Technology

David Austin, P.E.
North American Wetland Engineering
White Bear Lake, Minnesota, U.S.A.

to my surprise:
"...The first engineered treatment wetland design is found in a 1901 United States patent. Although the patent is surprisingly sophisticated, no record has been found showing that it was ever built. ..."
Constructed wetlands, soil filters and infiltration beds Fri, 19 Dec 2014 15:55:03 +0000
Key documents for the sub-category on constructed wetlands - by: muench For more information about why I am creating this new thread, please see here:


This thread is a "sticky thread" which means it will always remain at the top of this sub-category.
It contains a recommendation for new people regarding the most important 3-5 documents in the thematic area of "constructed wetlands".

The initial selection was done by me, but this is open for discussion and can be adjusted regularly.

Recommended top 5 documents in the thematic area of "constructed wetlands":


Hoffmann, H., Platzer, C., von Münch, E., Winker, M. (2011). Technology review of constructed wetlands - Subsurface flow constructed wetlands for greywater and domestic wastewater treatment. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, Germany

This booklet focuses on treating domestic/municipal wastewater or greywater with subsurface flow constructed wetlands with coarse sand as a filter medium. The emphasis is on the application in developing countries and countries in transition. In the publication, an overview and basic guidance is provided on the design and maintenance of horizontal flow beds (HFBs), vertical flow beds (VFBs) and the “French System”. A description of the most common pre-treatment systems is also included due to their vital importance for the proper functioning of CWs. The target audience are people with some basic technical background who want to obtain an overview of subsurface flow constructed wetlands, their designs, performance and maintenance requirements.
The work for this publication was funded by the Deutsche Gesellschaft fuer Internationale Zusammenarbeit (GIZ) GmbH on behalf of the German Ministry for Economic Cooperation and Development (BMZ).

A Spanish version is also available, see in SuSanA library.


Morel, A. and Diener, S. (2006). Greywater management in low and middle-income countries, review of different treatment systems for households or neighbourhoods - Sandec Report No. 14/06. Sandec (Water and Sanitation in Developing Countries) at Eawag (Swiss Federal Institute of Aquatic Science and Technology), Dübendorf, Switzerland

This report compiles international experience in greywater management on
household and neighbourhood level in low and middle-income countries. In urban areas of LMIC, greywater is commonly discharged untreated into drainage channels, use untreated greywater for agricultural purposes, thereby leading to environmental degradation and exposing the population to health risks. Though greywater is generally less polluted than domestic or industrial wastewater, it may still contain high levels of pathogenic microorganisms, suspended solids and substances such as oil, fat, soaps, detergents, and other household chemicals.

Langergraber, G. (2013). Are constructed treatment wetlands sustainable sanitation solutions? Water Sci Technol 67(10), 2133-2140, doi: 10.2166/wst.2013.122

The main objective of sanitation systems is to protect and promote human health by providing a clean environment and breaking the cycle of disease. In order to be sustainable a sanitation system has to be not only economically viable, socially acceptable and technically and institutionally appropriate, but it should also protect the environment and the natural resources. ‘Resourcesoriented sanitation’ describes the approach in which human excreta and water from households are recognized as resource made available for re-use. Nowadays ‘resources-oriented sanitation’ is understood in the same way as ‘ecological sanitation’. For resources-oriented sanitation systems to be truly sustainable they have to comply with the definition of sustainable sanitation as given by the Sustainable Sanitation Alliance (SuSanA, Constructed treatment wetlands meet the basic criteria of sustainable sanitation systems by preventing diseases, protecting the environment, being an affordable, acceptable, and simple technology.
Additionally, constructed treatment wetlands produce treated wastewater with high quality which is fostering reuse which makes them applicable in resources-oriented sanitation systems. The paper discusses the features that make constructed treatment wetlands a suitable solution in sustainable resources-oriented sanitation systems, the importance of system thinking for sustainability as well as key factors for sustainable implementation of constructed wetland systems.

Case studies of the Sustainable Sanitation Alliance on UDDTs:

There are oviously many more important documents dealing with constructed wetlands:

The Wikipedia page on constructed wetlands can also be recommended:

Constructed wetlands, soil filters and infiltration beds Wed, 10 Dec 2014 10:38:05 +0000