Dear SOIL,

Thanks for this excellent blog post on the design of the SOIL household toilet. It’s a real inspiration to others who are facing similar design challenges, and it is comforting to know that a healthy dose of trial & error went in to arriving at the current toilet model. I hope that this open sharing of your story will encourage others (SANERGY, X-runner… ) to share their respective histories of toilet design.

By way of a prequel to the blog, I would like to share a couple of earlier SOIL toilet models, which I hope will shine a light on some other aspects of toilet design which were considered at the beginning of the SOIL design process.

During the re-launch of SOIL’s household toilet design process in 2010, we started with a dual approach to design, considering both technical aspects like size; materials; ergonomics; and cleanability, and emotional aspects like pride and dignity. Working off existing examples of functioning and accepted household toilets, the design process began with the toilet in use in the SOIL office in Cap Haitian, which was a cement UD toilet using a ‘Cesar’ mould imported from Mexico, installed within a very comfortable, attractive, well ventilated space on the balcony (see figure). This toilet was in fact modeled on an even more attractive household toilet in Durban, South Africa, which can be seen on this previous SOIL blog from 2012: www.oursoil.org/soil-returns-to-its-roots/.





Using the comfortable ‘Cesar’ toilet style to work from, we were strongly influenced by emotional drivers: Could it be possible to design a household toilet which provided for sanitation needs but was also a point of pride for a household? Could a household toilet be something that users could show off? Something which (when not in use) could perhaps have a secondary function as, say, a table? What exactly was it that household toilet customers wanted? What was meant by 'aspirational sanitation', according to our customers?

Our research in 2010, indicated very strongly that the flush toilet was the most popular toilet model in Haiti. More recent research by DINEPA in 2015 also strongly asserts that this is still the toilet of choice for the population. So, with lofty ambitions to compete with the flush toilet, we embarked upon our own ‘reinvent the toilet challenge’, and developed our first toilet model in early 2011; The Tank. The Tank tried to mimic the flush toilet, with a ‘cistern’ containing cover material actually attached to the toilet in the usual cistern position (see picture of SOIL directors Sasha & Bobo explaining ‘The Tank’ during a group design meeting in Citey Soley). To truly mimic the WC, we spent quite some time brainstorming release mechanisms for the cistern, to ‘flush’ cover material over the fresh poop. Our inspiration here was Henry Moule’s earth closet (see figure), patented in 1873, which would eventually lose its market share, due in no small part to Queen Victoria’s adoption of the water closet in 1860. Despite our creative ingenuity, this ‘flush’ was finally deemed unfeasible and dropped from the toilet’s design – this design challenge remains for toilet inventors out there, like SOIL's partner Re.Source, of whose work on the Universal cover flush, we are excited to hear more.










The Tank’s main drawback was its size; it was too heavy, too big, and too expensive to consider for most households. The 2011 “Artsy Wooden Box” was our attempt to reduce size, but still have a built-in storage space for cover material. The cover material ‘cistern’ was deemed an important design item to maintain because the toilet does not work without cover material, and users may forget this if the cover material container is not built-in. Future design iterations proved this assumption to be untrue, and a reliable cover material supply service, coupled with the toilet users knowledge, proved adequate, and the ‘cover material cistern’ was consigned to design history.

Since those early days of toilet design, SOIL has learned a great deal about what its customers want, and about how to best provide it. With each new toilet installed comes a new learning experience, and new toilet iterations are always being discussed and developed.

What I personally find remarkable about this story of toilet design, as well as the development of a beautiful, affordable, household toilet unit, is also the change in perception of toilet users, and observers alike. Whereas our design process started in 2010 with a challenge to re-invent the toilet, and compete with the water closet, this is no longer a considerable driver. And whilst it can be assumed that there will always be a market for WC’s, we need not look upon the WC as a toilet design to be bettered, or reinvented, but rather as a design alternative, with a very expensive and intensive system of infrastructure support (water supply, sewerage and wastewater treatment) which SOIL’s toilet does not require. Indeed, this paradigm shift which is often talked about with mystical reverence, is happening in Haiti now exactly because of SOIL’s toilets. There are real examples of households in Ti Place Cazeau (one of the few areas in Port-au-Prince with a sewerage network) removing flush toilets and replacing them with SOIL toilets. And whilst we may certainly praise the many years of design iterations, of trial & error, of lessons learned from customers both happy and unhappy, we must also recognize the huge impact of SOIL’s educational and outreach programme which accompanies all of its sanitation projects, from household toilets to mobile toilets, which has lifted the environmental consciousness of toilet users, so that ‘flush & forget’ is no longer an admirable and convenient design feature, but rather a illusory and dangerous one, which causes human disease and environmental destruction: So lets replace ‘flush & forget’, with ‘poop & cover’.

Bravo SOIL! The sanitation revolution is underway!

Meme le pipi de crapauds fait descendre la rivière - for those who speak French.

Congratulations for this low cost toilet! A few additional questions from my side:

How big are the containers inside, and how frequently are they serviced?

And did you ever attempt to calculate the total costs of your sytem on a per person per day basis? (for the sake of comparison, using that 5 or 6% discounting rate).

Thanks, H-A

Dear Elisabeth,

Thank you for the thoughtful response. We love questions like these!

"Were you ever in danger of "losing" your customers or were they patiently waiting for you to come up with better models? I guess they get the toilet at a very subsidised cost so they didn't "jump ship" or what was your experience with your customers during those six years?"

We are currently adding about 45 customers per month to the EkoLakay service and we have about 5 people drop off every month. The main reason identified for leaving the service is the cost - we charge approximately $5 USD for monthly waste collection and toilet servicing. Even though our attrition rate is already low, I expect it to go down further. We still have some people on the service who signed up in the early phase of our pilot when we were charging less and/or not following up on non-payment. Now that people see we're serious about collecting the monthly fee, only people who are fully aware of the financial obligation are signing up.

Our commitment to design excellence comes from our desire to keep our initial construction and maintenance costs extremely low and from our desire to provide our customers with a high quality service they can be proud of. While we are not yet fully satisfied with our current toilet design - our quest for perfection is never ending - we do not think people were leaving the service because of design flaws. The SOIL team is quick to respond to customer complaints, and we worked with our customers to resolve any design problems that arose in a timely manner. This kept our customers happy (and therefore unlikely to leave the service on account of design flaws), but it also kept our costs higher. We found that having grant and donor funding to subsidize these early R&D costs has been critical to our success.

[i"]In hindsight, is there anything you could have done differently to arrive at your current design faster? Could you have received better advice from some experts to find the optimal solution faster?"[/i]

We had a rapid improvement in our design with Re.Source Sanitation joined us - so yes in hindsight it would have been nice to have experts sooner in the process! And hopefully people who choose to implement similar projects in the future can take advantage of all this R&D work to start out with a more optimal solution to the one we started with.

Do you think you have reached the optimal solution now?

Never! The quest for perfection continues! Truly we are very pleased with our current design but we continue to welcome design improvements that further reduce costs and further improve the user experience.

"Interesting that your latest toilet model has no bottom; I guess that could lead to seepage of urine into the ground if the urine container overflows?"

Because these toilets are in people's homes they tend to notice the overflow very quickly and empty the urine container regularly. This prevents long-term issues with seepage. Also many people just incorporate a quick urine container check in their daily household cleaning, thereby obviating any overflow issues.

"Your work however shows that it's too simplistic to speak of success/failure in a binary mode. There are many shades in between, and a failure today can be turned into a success tomorrow if we learn from the shortcomings and improve on the design. Right? Perhaps the point is not to give up and to have a long-term, patient view, not a short-term "3 year project cycle" view..."

This is exactly how we work at SOIL. We are dedicated to building dignified, affordable, sustainable sanitation solutions. This is a long-term commitment. If something we try fails, we try to learn from that failure to improve the next iteration. It's been a long slog - we're approaching our 10-year anniversary!! - but 2,400 people are currently using a SOIL EkoLakay toilet in Haiti and this number is growing daily. We are also pleased that we can help other implementers around the world learn from our successes and failures. If one learns from their mistakes and makes something better because of it, perhaps failure is just a necessary part of moving forward. Reminds me of the Haitian proverb that "pipi krapo fè rivye a desann" - "[even] frog pee helps the river flow."

Warmest wishes,
Leah

Leah Nevada Page, SOIL Development Director

Dear SOIL team,

Thanks a lot for putting this together: 6 years of trials and tribulations of different low-cost urine diverting dry toilet seats for households in Haiti! That's a really interesting story. I see you had a few comments on your blog about it, too:
www.oursoil.org/the-long-and-eventful-jo...ehold-toilet-design/

I am just wondering: were you ever in danger of "losing" your customers or were they patiently waiting for you to come up with better models? I guess they get the toilet at a very subsidised cost so they didn't "jump ship" or what was your experience with your customers during those six years?

In hindsight, is there anything you could have done differently to arrive at your current design faster? Could you have received better advice from some experts to find the optimal solution faster? Do you think you have reached the optimal solution now? (interesting that your latest toilet model has no bottom; I guess that could lead to seepage of urine into the ground if the urine container overflows?)

We hear a lot about "sanitation failures" these days. Well, it was Susan Davis from Improve International who brought it up for me, she also presented at the recent SuSanA meeting about it (see also this thread here: forum.susana.org/forum/categories/183-mo...ents-the-netherlands). Your work however shows that it's too simplistic to speak of success/failure in a binary mode. There are many shades in between, and a failure today can be turned into a success tomorrow if we learn from the shortcomings and improve on the design. Right? Perhaps the point is not to give up and to have a long-term, patient view, not a short-term "3 year project cycle" view...

Regards,
Elisabeth

SOIL's Cap-Haitien EkoLakay Program Coordinator, Marion Cherrak, wrote out a brief a history of SOIL's toilet design process in order to share with you - "EcoSan lovers, SOIL fans, and toilet developers around the world!" The current household toilet model that SOIL uses is a durable, user-approved, UD, EcoSan toilet costing less than $30 USD to manufacture. But it was a long and evolved design journey to get to this point and you can read the full scoop on the SOIL blog at: www.oursoil.org/the-long-and-eventful-jo...ehold-toilet-design/

We believe that our design process might be interesting to other SuSanA readers as we've run trials of many different technologies and construction techniques and have 8 years of iterative design experience informing our current toilet model. We welcome your questions and comments!



Are you curious how we got from this clay pot toilet (very breakable and requiring imported products):


To this beautiful ferro-cement toilet built locally for less than $30 USD:


Read all about it on the SOIL blog at: www.oursoil.org/the-long-and-eventful-jo...ehold-toilet-design/

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