Saving Water, Twenty Million Gallons at a Time

  • EkoLakay Toilet

Two things we know to be true about SOIL’s crew: we’re data driven to our core and we’re really passionate about poop (or about finding innovative ways to transform it from something that wreaks havoc on the environment and public health into something that combats climate change and grows more food!) So, it won’t come to you as a surprise that our resident Composting Advisor Julie Jeliazovski decided to start tracking the number of times we were all using the restroom in SOIL’s office bathroom (aka our test lab!). She was hard at work crunching numbers to determine just how much water SOIL’s sanitation service is saving in Haiti when families use one of our dry, composting household toilets. Spoiler alert: it’s a lot.

A Run Down on Growing Global Water Scarcity

According to FAO, 2 billion people around the world live in areas plagued by physical water scarcity and another 1.6 billion face water scarcity due to a lack of the necessary infrastructure to bring water into their communities. And as a result of the impacts of global climate change, the crisis is only anticipated to worsen. Half the world is expected to be living in high-stress water areas by 2030. We see this reality every day in the communities where SOIL works in Haiti: water is expensive, hard to come by, and so often unsafe to drink. Just 62% of people living in the country have access to an improved water source. 

As you might know, there currently aren’t sewage systems in Haiti and it’s unlikely that they become the prevailing paradigm in the country even in the long-term because of contested land tenure in urban settlements, the enormous amount of up-front capital required, and the necessity of steady water and energy supplies to operate the systems. But – even if it were feasible in the coming years to install sewer infrastructure – might it be better to instead invest in regenerative solutions that protect the environment instead of draining our scarce water resources? We say yes!

Developing Regenerative, Resilient Solutions

Here’s how SOIL’s waterless toilets work: SOIL’s sanitation service deploys a technology called Container-Based Sanitation (CBS), where toilets collect human waste in sealable, removable containers that are transported to treatment facilities when full. Instead of requiring a flush and a great deal of water to transport the waste and accompanying wastewater, the “flushing” actually comes in the form of organic material which keeps the toilets smelling nice and facilitates the process that transforms the waste into lush, agricultural-grade compost at our waste treatment site.

Let’s Add it Up! 

One of the most water intensive household activities in a household is the flush of a toilet! In the US, it’s the single highest source of household water consumption. Most adults urinate 6 to 8 times per day, and the standard flush is 6 liters (or 1.5 gallons), though it’s often significantly higher for older toilet models. That’s a lot of water day that could otherwise be used to drink, shower, or grow food!

Though SOIL’s toilets themselves don’t require water, along the sanitation service chain there are a few places where water is necessary: when SOIL sanitizes the containers once they’ve been emptied, for employees at the composting site to use to shower after work, and to wash the uniforms of members of the composting team. Because SOIL is working to develop a sanitation solution that can be replicated by communities across the globe, we meticulously track key performance indicators. That means we already had this information on water inputs per container accessible (~34 US gallons in Port-au-Prince*), we just needed to figure out how many times it took for a family (or office) to go to the bathroom (when they would otherwise be flushing) before their EkoLakay container is filled.

After a few months of tracking, we determined that this number is 187. Let that soak in! Every filled EkoLakay container saves 187 flushes worth of water. What does that mean for SOIL’s operations at large? That means that, even taking into consideration the water usage at the composting site, a household using SOIL’s household sanitation service is saving on average almost 20,000 gallons of water per year as compared to a family using a flush toilet.

Currently SOIL serves nearly 1,100 households with our sanitation service, and we use an estimated 2.6 million*** gallons of water per year. If all 1,100 of those households were on flush toilets**, the total water use per year would be nearly 24 million gallons, meaning the total annual water savings from SOIL’s system compared to flush toilets is more than 21 million gallons of water. That’s a lot of water that would otherwise be flushed down the drain.

We hope someday we’ll be able to do an even deeper dive into this research on relative water savings. Some questions we’d be excited to explore: how does a different grind on the carbon cover “flush” material impact the amount of waste that can fit into one container?  How does the water savings differ between SOIL’s operations in Cap-Haitien* and SOIL’s operations in Haiti’s capital city, Port-au-Prince?

What other questions should we be asking? Let us know in the comment section below and be sure to sign up for our monthly newsletter to hear directly from our teams as we continue to conduct groundbreaking research on SOIL’s ecological sanitation solution.

To learn more about the climate-positive sanitation urban sanitation systems that SOIL is incubating in Haiti, visit

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*Because SOIL’s teams in Cap Haitien are able to work much more efficiently at a larger scale, they are able to manage the service with far less water per container, though we’re working to reduce water consumption at both sites. The results in this blog are just using figures from SOIL’s operations in Port-au-Prince, meaning that the overall water savings of SOIL’s sanitation services, as well as the current use of water to manage the service for 1,100 households, is likely much higher!

** Using conservative estimates both in average trips to the bathroom per day and in the amount of water used per flush toilet. We calculated the average flush at 1.5 gallons each, but some research indicates it’s actually closer to 3.5. We also only used the figures for household water consumption and didn’t try to estimate how much additional water might be used at the treatment facility. Meaning that this analysis, despite already being incredible, underestimates SOIL’s total water savings compared to traditional technologies.


Water Use Comparisons Table


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3 Replies to "Saving Water, Twenty Million Gallons at a Time"

  • Dana Vialli
    August 13, 2018 (7:53 pm)

    SOIL remains the most exemplary ecology organization I know of, just as Jenkin’s ‘The Humanure Handbook’ is the best book on ecology I have ever read. Unfortunately most ecologists have not heard of either.

    • SOIL Haiti
      August 14, 2018 (5:38 pm)

      Thank you, Dana! Your words mean a lot to us. We hope that people will continue to learn about ecological sanitation solutions and will continue to work hard to publicize what we do in an effort to support that.

  • Jessica wiliam
    June 24, 2022 (3:19 am)

    Thank you for sharing useful information that I care. This article is so great.

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