Part of the foundation work requirements for École Elie Dubois in downtown Port-au-Prince commanded that a 9-foot deep, 15-foot wide hole be dug in a corner of the school's site. Then the builders were to make a domed structure that no human would ever occupy–and a structure that doesn't have much architectural precedence in Haiti, maybe five years. But this underground container is supposed to be watertight and can help with the school's energy needs. These strange instructions are the start of a biodigestion system for the school–and serve as an answer to a riddle baffling designers throughout Haiti's reconstruction: how should Haitian dispose of their waste?

Throughout the reconstruction effort, significant attention has been paid to possible solutions of turning human waste into a usable byproduct. Up until the earthquake (and in plenty of instances since), sanitation has been a problem, a health issue, or a crisis of epidemic proportions. School buildings are particularly susceptible to the spread of pathogens to vulnurable populations. But in Haiti, proper sanitation comes at a premium. The bathrooms of most schools can't but be simple pit latrines–pits that, when filled are covered with dirt, instigating the resituation of the latrine somewhere else on the schoolgrounds.

A more or less typical pre-quake Haitian school latrine

More fortunate schools such as at Elie Dubois have employed cisterns on site to collect waste. Cisterns store the waste in underground containers which are then emptied every 3-5 years by a truck, and the contents are taken to some off-site "facility." One hesitates to use the term "Waste Management" because to date in Haiti, there isn't any. Typically waste is trucked to the city dump to co-mingle with general garbage.

So there's something missing in Haiti's waste management infrastructure, but before any plans by international aid organizations were laid for a waste treatment center (or, heaven-if not economics-forbid, municipal sewage infrastructure), grassroots groups have been doing what they could with localized waste treatment solutions that could rely less, if at all, on a larger system to dispose of what could be a very lucrative byproduct.

The fact of the matter is: poop makes some really great fertilizer. Given the right amount of time and one of a diverse menu of processes, human waste can transform into nutrient-rich matter for distribution on agricultural land–land that, before Haiti assumed its distinctively tree-stripped and barren profile, was once among the most agriculturally-productive nations in the world. With the combination of a favorable climate and a cooperative population, there seems to be limitless potential to kickstart an agricultural renaissance for the island nation.

Yet fertile land alone cannot secure Haiti's promise to farm and reforest. Some of these continued problems stem from a reliance on charcoal for cooking. Charcoal can be produced from trees at basically any stage in their life cycle, and charcoal has become a fairly large industry in Haiti, threatening its ability to reforest.

A garden and a fish farm, both fed by a biodigester

Enter Brazil-based VivaRio, an organization that has been working in Haiti since 2005, and has built at its base of operations what it envisions to be the futrue for Haitian waste management. In the community of Kay Nou, in Bel Air, as well as in 50 other locations around the country, VivaRio is simultaneously collecting cooking fuel and fertilizer through its biodigesters. While the solid sludge output is generally ready to enrich soil, VivaRio emphasizes their system's ability to turn a byproduct gas into a cleaner-when-burned cooking fuel to offset the owner's reliance on charcoal.

The biodigester's domed structure has to be built to collect solid waste in a controlled chamber and be processed by bacteria. The byproduct of this "anaerobic" process is solid sludge fit for fertilizer, and methane gas. The methane, rising to the top of the dome, can be piped to the kitchen and put to work! Meanwhile, liquids from the biodigester are siphoned into what's called a "living machine," where plants in a leach field help to clean the effluent released from the tank.
Design section of Elie Dubois campus–including cafeteria/kitchen, toilet block and biodigester
A section of a biodigester (left), and what it looks like when it's finished (right)

Construction of Elie's biodigester is now underway–soon it will be hooked up the the latrine block on one end and the kitchen on the other and become an environmental and economic machine working on behalf of the school. The toilet system the school has opted for is a flush system like you would find in most bathrooms in the US. The system is comfortable, effective, but requires a lot of water. For this the school's system incorporates a large water collection cistern to help with the water consumption load. The team is anxious to study the performance of the Elie biodigester to see its potential in "pour flush systems" (using only 1-3 L) or "dry" systems which require no water at all.

Elie currently doesn't have plans of reusing its sludge and opts to continue trucking it off-site as had been done from their cistern before the quake.






Check out this RAD video of how the dome comes together–genious!

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