Inside SOIL’s Laboratory in Cap-Haitïen: How We Test Our Compost

Behind every bag of SOIL’s KonposLakay compost is a careful process to ensure it is safe, free of harmful pathogens, and ready to restore Haiti’s soils. Each batch is held to rigorous standards in compliance with the Haitian government’s requirements for processing waste as well as the World Health Organization (WHO) safety guidelines. This level of quality control certifies that our compost is not only suitable for farmers to use on their crops but also contributes to healthier ecosystems throughout Cap-Haitïen.

At SOIL’s waste treatment site, the only facility treating human waste in northern Haiti,  Lab Technician Lenot Philistin conducts the testing of each compost pile. We visited him in Moucinette to learn more about the compost testing protocol and its importance.

“The main work of the lab is to test and measure Total Coliforms and E. coli. This is our main pathogen of concern when dealing with human waste. We also want to make sure SOIL’s sanitation workers at the composting plant are not exposed to contamination and to ensure the compost is safe for farmers.” (Lenot Philinstin)

In the Mouchinette lab, Lenot relies on three main pieces of equipment:

• IDEXX Quanti-tray sealer
• Incubator
• UV light

These tools (along with a scale, blender, graduated cylinders, and glass pipettes) allow him to detect the presence of pathogens and verify that the compost has reached safe, agricultural-grade quality.

The Testing Process

Testing follows a regular weekly rhythm. Mondays are spent cleaning and preparing the lab  and Tuesday is test day. Results are analyzed on Wednesday and then sent to the Waste Treatment supervisor.

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Here are the five steps of SOIL’s customized compost testing process:

1. Compost samples are taken from different locations of each pile and blended with water.
2. A reagent (Colilert®) is dissolved into the sample to aid detection of the presence of E. coli.
3. The prepared sample goes into the incubator for 24 hours.
4. After incubation, a UV light is used to gauge whether E. coli is present.
5. Results are documented and shared weekly.

In addition to these weekly tests, once a year SOIL sends a sample of compost to a laboratory in France for additional microbiological and physicochemical analysis. These external lab analyses add another layer of assurance that KonposLakay meets international safety standards.

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Lenot taking a sample from the compost pile to show us the testing process. 

Meet Lenot!

Lenot joined the SOIL team in 2017, after working in a medical lab in Cap-Haïtien. He was trained by one of SOIL’s former agronomists and has been leading compost testing since.

When asked what he finds most interesting about his work, he shared:

“Knowing that I test compost in order to prevent people from getting sick is meaningful—for the health of farmers, communities, and our sanitation workers.”

Thanks to Lenot and the waste treatment team, every bag of KonposLakay is not only a product of ecological transformation but also of rigorous science and care. There are often many logistical difficulties in getting lab supplies to the office, and we are incredibly thankful to our monthly supporters whose donations ensure that these materials are consistently available. 

Compost testing may happen behind the scenes, but it’s at the very heart of SOIL’s mission to build safe, sustainable sanitation in Haiti with evidence-based solutions.