forum discussion #36

Toilets: Clean Talk on a Dirty Subject

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Listen to our interview with Arno Rosemarin here.

Rosemarin is an expert on sanitation. He works at the Stockholm Environment Institute, and he’s our guest in this Science Forum discussion. He’s taking your questions about sanitation and toilets.

Why talk about toilets? Because even today — in the 21st century – a third of the world does not have access to basic sanitation. The result: water and soil pollution, and widespread health problems like cholera and dysentery.

Sanitation is “something that human beings have… trouble talking about,” says Rosemarin. But he contends we must get over our aversion to the subject if we are to solve the earth’s sanitation challenges.

So how can we provide basic sanitation to those who don’t have access to it? And would you be willing to trade your flush toilet for a more earth-friendly design? Bring your thoughts and questions to the conversation.

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Although the modern flush toilet carries away our waste and reduces the transmission of disease, it uses a lot of water. In China, toilets account for up to half the water used in a typical household, worsening the country’s chronic water scarcity.

Rosemarin would like to move people away from flush toilets, but that is no easy task. When he tried to introduce a sustainable, dry-composting toilet in a Chinese city, unforeseen problems prevented the toilets from working properly. You can listen to that story at the top of this page, or read it here.

Follow our Toilet Tales from China, India, Haiti, and the U.S.


The guest has left this discussion, but feel free to leave your thoughts.

Your Comments

  1. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

    Now that the world consists of 50% urbanites, one can say that half the world is sufficiently disconnected from nature that they no longer understand how vulnerable they are nor or how dependent they are on ecosystem services. This is true for all cities, rich or poor, small or mega-sized. Lack of safe sanitation in densely populated urban areas contributes to killing 5000 children every day. And there are about 1 billion open defecators and additionally 1.5 billion with inadequate sanitation facilioties. The lack of dialogue on human sanitation and our increasing dissociation from nature presents itself as a new and challenging cross-roads for all humanity to grapple with.

    • Pinnock

      Dear Arno,
      Great work and good thinking, I’m in line with you and I believe we should stop being squeamish about what we by nature have to ‘eliminate.’
      Also, what design or process do you think is best as a dry toilet, and secondly, what is the best treatment for grey water? Thanks.

  2. Rich Sewell

    I live in Alaska, USA and there are many remote villages that have no flush toilets with sewage systems. Many villages have still have “honey buckets” for toilets, which are 5 gallon buckets that are then hauled to an open sewage lagoon; this is in the United States of America.

    There have been some improvements including “flush and haul” systems. Still remote communities need different solutions such as “dry toilets” to prevent cross-contamination of drinking water. Perhaps the Stockholm Environment Institute can contact the State of Alaska and the Alaska Native Tribal Health Consortium to help with this problem.

    • Magdalena Rangan

      Regarding “Dry Toilets”:
      It’s a matter of supply and demand. If there weren’t so many of us, we humans wouldn’t have these problems. Instead of technology trying to solve the insolvable problem of earth’s ever shrinking natural resources, especially water, why not advocate birth control, which would, over the years, reduce the human population?
      As it is, the human population is growing at an exponential value, but no one has the guts to address the looming specter of gloom, caused by overpopulation.

      • AnnieD

        Yes, contraception and slowing the world’s population growth is vital, but the bottom line is whether you’re talking about a household of 1-2 people or a community of hundreds/thousands/millions, you’ve got to have a safe, effective method of dealing with human sewage. Failure to do so can only result in illness (whether acute or chronic) and death.

        “Dry” composting toilets really seem to such a simple yet elegant solution

  3. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

    Permafrost means no sewage pipes are possible unless they are elevated and heated. I believe you have such systems eg in Anchorage making these the most expensive sewers in the world. Urine-diverting dry systems are really ideal for these conditions and the volumes of fecal material will be so much less than the water mix in the large buckets you describe (only a liter per person per week). There is knowledge in the US on these alternative systems. Try getting a copy of The Composting Toilet System Book: A Practical Guide to Choosing, Planning and Maintaining Composting Toilet Systems An Alternative to Sewer and Septic Systems [Paperback] by David Del Porto and Carol Steinfeld.

  4. Amy F

    In the early 70′s I experienced a “Clivis Toilet” which had been well-functioning in use in a home and emittting no odors. I should mention that the resulting fertilizer was by decree (in a USA city)useable only for non-food related gardening. Of course the stack was necessary! The one feature I miss in your article is the regular (electric) aeriation and rotation, similar to all good composting practices. Since this type of toilet has been in rural use in Scandinavian countries for some time now, is the main difficulty in adaption to concentrated urban living situations?

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      There are successful dry toilet projects in urban areas for example in Sweden, Germany, South Africa. Take a look at and the case studies. For a complete digest on sanitation technologies please see . Yes mixing and aeration is necessary to enhance good composting conditions. But ideally the toilet should be an easy to use containment device and composting should be carried out as a separate addtional step with added carbon sources in a thermal compost that will also kill pathogens. The Clivus Multrum can take urine, faeces and kitchen wastes and the compost heap can remain in place for several years before it needs emptying. This is an ideal toilet also for public areas and highway stops.

      • Carol Steinfeld

        There are many urine-diverting and combined (urine is not diverted) composting toilets in the United States and Canada—from rural Alaska to New York City. Several urine-diverting flush toilets are also in place in California, Vermont, Florida, and Massachusetts. Some flush blackwater (feces) to composters and some flush to the sewer with as little as .2 gallons of water. Some of these systems have permits. Don’t miss this year’s EcoToilet Summits in Massachusetts and Washington DC. See this recent short article noting systems in Chicago, San Francisco, and Oakland:

  5. Robin rogers

    Living in metro Chicago, how do we get to go on this topic? Codes and politics are real blockers. I want to protect and conserve our bountiful water resources–proximity lessens our urgency for change. How do we begin the local discussions? Bringing a shift in thinking about something so mundane and commonplace eludes most American consumers. Enjoyed this evening’s discussion–will look to move this topic to our local leaders.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      The sanitation sector attracts little or no dialogue and taxpayers and politicians don’t know how expensive these systems are to build and maintain. It is only after disasters like Katrina and tsunamis that render vital water and sanitation systems dysfunctional that the public dialogue begins. Chicago surely practices source separation and recycling of solid waste. Kitchen wastes are the bulk of what cities produce and need to be recycled back to the soil. Production of biogas fuel for our precious vehicles may be the key to kick starting the entire process of collection and reuse of kitchen organics, sludge from sewage plants and humanure. Take a look at “The Big Necessity: The Unmentionable World of Human Waste and Why It Matters” by Rose George.

  6. Laura

    i think this is a basic essential topic. More should be done to develop low cost ecologically sustainable sanitary systems that don’t require water. In the meantime, in the US, where we have access to quality plumbing, toilets in our public schools are disgusting due to budget cuts and lack of janitorial personal. What does this say about one of the wealthiest nations in the world?

    Also, aside from the serious health problems caused by this challenge, I think this is a particularly important issue for women in developing nations. Women have to deal with monthly bleeding and not having access to privacy and sanitary toilets is horrible for any woman.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Rhitu Chatterjee

      Hi Laura,

      The World’s science reporter here. You bring up an excellent point about sanitation issues affecting women in particular. There’s also a link between that and primary/secondary education among girls. In India where I’m from, poor sanitation in schools is a BIG reason for girls dropping out of schools, especially in rural, semi-rural areas. I can imagine it’s the same in other developing countries as well.


    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Yes without proper financing, maintenance workers will not be given the respect they deserve and eventually the work will not get done. Our careless attitude about toilets especially in schools may be creating a young generation lacking values and morals.
      Menstruation management with proper toilet facilities is the key to keeping girls in schools in the developing world. The lack of sanitation facilities often means an abrupt termination of schooling and instead early arranged marriages. This contributes to enhanced global population growth. Keeping girls in school by providing hygienic toilet facilities could be as important in preventing global warming as the shift to renewable fuels. And what about the huge benefits to society with the associated increase in literacy?

  7. Nicole

    After the earthquake in Haiti, there was cholera outbreak which claimed the lives of many people. Japan is recovering from an earthquake and Tsunami, but we do not receive news on their current sanitation issue. Natural disasters occur in developed and developing countries. People are most vulnerable to infection and diseases after a natural disaster. Can eco-sanitation be used after a natural disaster to properly and safely handle human waste? Thanks

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Ecosan can be used to certain advantages. There are urine-diverting portable seat toilets that can be shipped flat and used directly upon arrival to the disaster site. Draining off the urine into containers or directly into the soil covered by vegetation means reducing the volume in the toilet compartment which can be lined with a biodegradable plastic bag for easy emptying. We urinate 10 times the volume of faeces so urine management makes sense. Urine is almost always sterile while it is the faeces that is the source of the pathogens that can make people sick. The source separated faeces can be contained and safely buried in soil or composted. Conventional systems mixing everything with water makes for high risk, large volumes and expensive impacts.

  8. If toilets take up about 50% of home water usage, couldn’t one design a plumbing system that took the other 50% of waste water from showers & sinks to direct to a storage tank? The toilets would then get their water from the storage tank. Thanks for your efforts.

  9. We work with under-served predominantly-minority neighborhoods across the US. Many of these have lots too small for septic systems but are without toilets because municipalities which are adjacent to them – and sometimes surround them – refuse to annex them. Failing septic systems in these neighborhoods endanger the health of the residents – and sometimes the larger community. In Modesto, CA, over 20,000 people live in predominantly-Latino neighborhoods on lots averaging 1/7 of an acre, and some of the houses are sinking into their yards, as soils become saturated from failing septic systems. The City has had to close some of its municipal wells because of nitrate contamination, which is associated with human and animal feces.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      The problem of informal settlements is a global one and it’s growing as the world becomes more urbanised. City managers often ignore both the people and their housing in these areas. Things can however be improved as in the case of the downtown slum in Dakar (Senegal) an area that the city was going to evacuate and pave over but with some organisational efforts it became an exhibit of successful cooperation with good maintenance, public latrines and showers, water kiosks, etc. Drainage is as important as water supply, sanitation, solid waste management, street lighting, security, etc. to create a better living environment. Willingness of the inhabitants to pay per use of such services can change the attitudes of municipal governments to assist in setting up entrepreneurial providers.

  10. Linda Peterson

    Once I actually saw the conditions of a school’s latrine in Paramaribo, Suriname, I worked very hard to help improve the sanitation for the children. Lack of an education due to reluctance to use non-existent or filthy facilities is unacceptable. Our Rotary Club has paired with other clubs to build latrine blocks, 330 schools have been listed needing facilities built or repaired. An education policy and responsibility to maintain will rest with each school.

  11. Dear Mr Rosemarin,

    I work in the development sector in India, namely the northern part of India. My focus area is school sanitation and hygiene education. Sesitizing school children on hygiene bahavior and toilet manners.

    But the main problem that I encounter always is the poor maintainace of school toilets in government schools. What and how do you think we can address this situation? What is your take on this.

    Has there been any international discussions and debates on the basic aspect of keeping the school toilets clean by other non-traditional methods like use of sweepers or cleaners.

    Eager to have your feedback.

    Rupak Roy Choudhury
    New Delhi

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Rupak, The World Tolet Association with its many national organisations has been trying to tackle toilet maintenance including schools. See
      See also the story about one of the famous pioneers, Trevor Trevor Mulaudzi from South Africa, an “Ashoka Changemaker”

  12. Kumar Rajnish

    Good Job Arno. This Ecological Sanitation can only solve the gigantic problem of sanitation. I already been in touch with your group and I also applaud the work of Prof. Tare of IIT Kanpur, India for doing this work on sustainable basis. During World Toilet Summit 2007 held in Delhi, India I was in one of the Workshop where ECOSAN technology was well explained and after that I knew what exactly is this and how we can change ‘mind set’ of the people from asian countries especially India, Pakistan, Bangladesh, etc. I am trying to promote this concept to a new generation especially school students and help them learning the behavioral change in thier families and neighbours. Clubbing this major issues with WASH activities so that children/youth could imbibe good habit.NPC,ENVIS, MoEF.

    • Hi, Kumar Rajnish: FIY. I am working on teaching around 20,000 pupils and teacheres to use the ecological toilets in Tian Shui city of Gansu province, China.It is a big challenge to have the pupils to use the toilet properly.Looking forward to sharing with you more about the education of children with toilets.

  13. AnnieD

    OK, now I’m really convinced–composting toilets can truly save the World! They’re the perfect solution to the problem of human sewage, particularly in Third World/Developing countries, since they don’t require any water, yield good-quality compost, and are easy to build and maintain. Forget porta-potties in places like Haiti-all they do is hold the sewage for moving to another location.

    And now to get personal: my sister and bro-in-law, who are truly living a pretty low-impact life in rural Florida, have both a composting toilet (which lives in a in a corner of the barn) and a standard toilet/bathroom inside. I’ve thus far declined to use the composting toilet when visiting, but I now vow to use it the next time I visit! Time to abandon my squeamishness and embrace the low/high tech!!

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Annie. The economy of scale for dry toilets and composting systems need to be examined along with other urban solid waste management, in particular kitchen organics that make up the bulk of what we produce. So solid waste services could take on dry toilets for peri-urban areas and small cities. But don’t forget greywater. This is the real challenge in sanitation. Once one gets into 200-300 persons per hectare, piping becomes more economic than on-site treatment so this is where innovation is needed. Greywater is the major volume product and could be dealt with in decentralised aeration and treatment systems.

  14. When i was young,all the water in the ponds around my village were drinkable even though we and the animals swam in it at the same time. But now, all the water is dirty even though the village is still the village i was born. You can not imagine all the villagers are using normal flush toilets polluting the water while they are using too much fertiliser hurting the soil day by day. In 2002, when i saw the waterless toilet for the first time, i had made my decision to promot it in China for returning a clean water to our next generations.

  15. In a way, the toilet process is in the middle of two real problems in the modern world: supply of water, and disposal of wastes. Classically, people have solved these problems by finding or developing new water sources, creating piping infrastructure (a major problem in itself) and then dumping the wastes in anything that gets it out of site (and smell) and hence out of mind.

    The supply of fresh water is nowhere as cheap as it used to be. And with global civilization (cities everywhere) we can no longer find easy dump sites. We have to clean up the water before dumping it in environmental “pools” like rivers and lakes. And simultaneously we have to clean up the supply because we have abused the general environment so much.

    One way to deal with all this is to recycle the waste water – take out most of the stuff we don’t want, THEN…. Wait! The cost of primary treatment is really low (remove all solids). The water is not usable for drinking. The cost of secondary treatment is much higher (remove organics and micro-organisms). The water is STILL not usable for drinking. The cost of tertiary treatment is astronomical.

    Here is what MAY be necessary: doubled piping systems. One set of piping for pure, drinkable water, another for everything else using recycled secondary treated water. MOST of the water would be used over and over, only a small amount would be new, drinkable water. Most efforts to deal with water problems attempt to produce drinkable water for everything. In the future, wont happen.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Louis. Just a short comment. Water that contains organics and pathogens cannot be reused over and over again. Methane and hydrogen sulfide gases would otherwise accumulate in the system and render entire cities dangerous and unliveable. There is a need to treat this water to render it safe and usable. So if we are going to use water to carry organic wastes, and there is good sense in doing so for urban areas, then we have to pay the price to treat it, reuse it and ensure the sludge products can be used in urban agriculture.

      • I’m sorry, I guess I am not an expert – I thought secondary treatment DID remove organics and pathogens (but not all dissolved salts – hence its unsuitability for drinking). All I am suggesting is that we are wasting an awful lot of money making sure all our urban water is drinkable. My next door neighbor uses drinkable faucet water to spray off her driveway! But my town (Palo Alto) is building a purple pipe system of secondary treated water to serve park sprinklers and business park irrigation. I’d like to see it everywhere, so we don’t have to keep importing fresh water from Yosemite and then flushing it down the storm drains, etc.

  16. Why is it that urine separation has become the norm when it has been shown quite reliably that with a Clivus style system you can get the same results without an awkward urine diversion device AND the liquid that comes out of the composting chamber is completely odor-free. Where as, with a urine diverting system it is very difficult to expect children, as was testified to on this thread, to use it appropriately and secondly the urine that comes out of a urine diverting toilet may be sterile…but it STINKS! Not to mention that even if you have a diverting system, but you don’t have a fan, the composting chamber will inevitably have bad odor as well.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Chris. Yes a Clivus Multrum is easy to use as you say but it needs a fan to prevent odors from coming into the toilet room. In developing countries where there is limited access to electricity, the easiest form of odor management is to use a urine diverted dry toilet that has a passive ventilation system venting the drying chamber. Ash is added to enhance drying and to increase pH to kill pathogens. The urine is diverted into a sealed container. The key to preventing odor in simple systems is not to mix urine and faeces. If the two are mixed then big odor problems occur due to ammonia production. Yes degrading urine smells, thus the need for a sealed container or direct drainage to a soil/vegetation bed. Dry toilets can be designed so that emptying takes place only twice per year.

      • Thanks for your response, Arno. My mom has been building composting toilets in Mexico for 20 years. In the areas where there is no electricity, she installs a fan with $90-300 solar panel. Now, I know you are going to say “thats too expensive for a third world toilet” but listen, if you are going to subsidize a toilet, do it well at the outset so that there is no smell! That requires a fan. And people will thank you for it. I am also skeptical of your assertion that the faeces should be dried. Overdrying prevents the proper aerobic conditions to maximize the effectiveness of composting. Our approach is to let the faeces sit in the composting container for a long period of time so that pathogens are contained and die as result of a competition with a host of aerobic bacteria.

  17. PS manual removal of excreta in buckets is a serious problem, IMO. It is totally inappropriate for urban situations.

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

      Chris. Agree with you. But we are not promoting removal of fresh excreta. The first contact is 6 months following the last use of the twin chamber. By then the contents of the chamber are bone dry and resemble dried soil. Gloves and masks are used when emptying a chamber or bin. This process has been accepted in India which has strict laws against scavenging.

  18. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

    re composting toilets vs dry toilets – 2 different things
    The Clivus is a toilet that carries out composting. Dry toilets do not compost but provide a first treatment to reduce pathogens through dessication, increased pH with additions of wood ash and time (eg 6 months to fill the chamber and 6 months additional time for pathogen dieoff). Dry also measn little or no odour. After emptying, the next step is thermal composting which is a hydrated step also requiring addtional organic carbon. The dry toilets can be used in areas that are dry, those with high water tables (chambers can be above ground) and in rocky areas where digging pits is difficult. Even in areas that are periodically flooded the chambers can be sealed so that the contents do not contaminate the local environment.

  19. Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? A_Rosemarin

    Hello everyone.
    This dialogue on sanitation shows again that humanity still has a long way to go. 2.6 billion people lack basic sanitation and 1 billion of these are malnourished partly because of the high cost of chemical fertiliser and food. 700 million people in 50 countries eat food irrigated with untreated sewage on >20 million ha of farmland spreading parasites and pathogens. Inadequate containment and treatment of human excreta puts people’s lives at risk. The recent outbreak of EHEC shows how vulnerable we are to hostile strains of intestinal bacteria that can be spread from animals to humans. But what about the spreading of intestinal pathogens from human to human, killing some 4000 kids per day? Sanitation is a human right, but not yet a reality.
    Arno Rosemarin, SEI.

  20. Lora

    Are there any sorts of considerations which must be taken regarding medication use in individuals who use composting toilets? Many medications are excreted through urine and feces. Getting proper sanitation is a health issue in its own right, but might this also be a health problem if such compost is used for food crops?

    • Error: Unable to create directory /home/worldsci/public_html//wp-content/uploads/2014/04. Is its parent directory writable by the server? Arno Rosemarin

      Here is a fact sheet
      The trace levels can be rendered inactive through biochemical degradation in the composting process. Pharmaceuticals will break down more efficiently in an atmospheric environment like soil since there is some 10,000 times more oxygen in air compared to water. Incineration of urine and faeces can be carried out for patients receiving high amounts of drugs. Here there is a need for risk assessment based on scientific evidence. Remember that animal manure also contains pharmaceuticals that the animals have been given. And there is a burden of pesticides on crops that can mask any or all of the other trace compounds. Question is whether the drug companies should be responsible to do these studies.

  21. Kent Green

    Mixing sewage and water is nearly always the source of sewage related health problems. If you have the money, means, technology, and scale, anaerobic is the way to go. If you don’t have those things, then the sewage should be mixed with air and composted on the spot. Mixing sewage with water and then flushing it causes endless problems, especially if it ends up more or less directly in the environment.

  22. Brett


    I have been listening to your toilet series podcasts as I visit rural farmers in Samoa. It has been thought-provoking. I manage agriculture, nutrition and sanitation projects throughout the South Pacific and the sanitation information on your podcast is very relevant in Papua New Guinea and Kiribati. Thank you for the good work and well-produced podcast.


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