Why let waste go to waste?

With a neon bucket swinging playfully in hand and a royal blue cooler slung over her shoulder, Maureen Kinyua looks like she’s headed for the beach. But her long pants, scuffed hiking boots, and red daypack suggest otherwise.

Born and raised in Kenya, Maureen received a scholarship to study in the U.S. and is now in her fourth year of pursuing a PhD in Environmental Engineering from University of South Florida. Maureen’s dissertation pertains to improving the health of people in developing countries, women in particular, through sustainable technology that is uncomplicated to install, use, and maintain.

“Environmental engineers and public health sometimes concentrate on water water water water [in developing countries]…but they forget livestock waste is such a big polluter of water,” Maureen said.

Enter the biodigester.

Maureen stands on a plank in front of UGACR’s farm biodigester. Microbe treated water gurgles beneath her as it flows from the biodigester.

It’s essentially a fancy word for waste cleaning machine. Waste, anything from human or livestock fecal matter to leftover scraps from meals, is disposed of into one end of a balloon-like cylindrical tube. With time, microbes trapped inside the digester break down the matter, mainly into water, carbon dioxide, and methane. These components are cycled into reuse, increasing environmental, social, and economic standards in a given location.

“You can provide people with a well, but then it gets polluted by livestock waste, so you’ve not really solved the issue, and you’re still not helping their economics or the environment,” Maureen said.

Her research, therefore, highlights the environmental, social, and economic benefits of the biodigester. Having received another grant to continue her research, Maureen has returned to UGA Costa Rica and the surrounding community to sample livestock waste and test it’s biogas potential. Out of curiosity, I tagged along.

I knew we made it to our first farm when Maureen slapped on purple latex gloves and glided on over to the pigpen. How elegantly she reached down, a yogi diving toward her toes. But instead of grabbing her little piggies, she snatched up a lump of poo belonging to one of the five oinking pigs curiously looking on. She zip-locked and stowed the sample in her bucket. Leaving the scene of sampling, we ducked below a thin blue pipe running from the biodigester in the garden, to the house, disappearing through the kitchen window. Maureen proceeded to educate me about the advantages of re-purposing waste.

Intrigued by Maureen’s sampling, the pigs investigate their visitors.
Intrigued by Maureen’s sampling, the pigs investigate their visitors.


  • Firewood is a common resource for cooking in developing countries. The demand for wood contributes to ecosystem destruction. Connecting the extracted methane gas from the biodigester into a kitchen, via a tube, decreases, and in time could offset, deforestation. It’s a new form of energy that requires existing waste to operate –waste that would be dumped otherwise.
  • Lowering the levels of jettisoned solid waste in water has its perks, too. Solids from waste get caught in fish gills, suffocating them, and block essential sunlight from reaching aquatic life. Solids release excess nitrogen and phosphorus, triggering algal blooms, which rely on microbes to aid with decomposition. The overbearing algae-microbe combo eradicates oxygen on which fish and other aquatic life depend.
  • Wastewater flows from the biodigester with fewer toxins and, because the liquid is fortified with natural remaining nitrogen and phosphorus, can be reused as fertilizer.


  • Indoor air pollution mainly affects women who cook with firewood. Microbe-made methane can replace wooden fires as a cooking source, reducing smoke and ash pollution in the home.
  • Microbe-treated wastewater that flows back into waterways is cleaner than solid waste dumping, lowering the risk of water-induced sickness.


  • Biodogesters release water that has nitrogen and phosphorus components. There’s no need then, to purchase mineral fertilizers that are toxic for the waterways in which they eventually end up. Farmers can simply water their crops with the excess biodogester water and save money doing so. In Costa Rica, neighboring farmers have saved between $20-40 per month after having installed a biodigester.
  • Less air and water pollution means less frequent, costly doctors’ visits for indoor pollution related illnesses.

Having heard about the positive effects of a biodigester, a local Costa Rican farmer eagerly asked Maureen, “when are you returning to build one?”

Blog contribution by Alex Fylypovych, UGA Costa Rica Photojournalism Intern

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s