Hektoen International

A Journal of Medical Humanities

A column of volcanic sand

David Gullette
Boston, Massachusetts, United States


The original all-concrete BioSand Filters we made for many years.
330 lbs without its sand.

Why shouldn’t a retired English professor devote himself to Public Health?

I fell hard for Nicaragua in the 1980s, organizing Boston academics against Contra aid, visiting the country in 1986 with Father Steve Chinlund, meeting the famous poet/priest and Minister of Culture Ernesto Cardenal, and beginning to work on a book about how newly-literate peasants (campesinos) in Ernesto’s Christian base community had started to write poetry. It was a natural fit for a lefty professor in his 40s: liberation theology, poetry, revolution, and a reason to head south to bisect the Massachusetts winter. The Campesino Poetry book was the first of three I would write about Nicaragua.

Hundreds of US citizens trekked down “to support the Sandinista Revolution” in the ‘80s. The mainstream mocked us as “Sandalistas.” Meanwhile, our Boston suburb of Newton had joined a nationwide movement of Sister City Projects. We partnered with the Nicaraguan town of San Juan del Sur, a charming Pacific coast port with a half-moon bay, raggedy fishing fleet, and weekenders from Managua. My wife and I were the first hands-on delegates, sprucing up existing schools and building new ones out in the scattered villages of the 250-square-mile township. We bought the materials and hired a master-mason, but folks in the villages did the hard work.

As the new century began I started taking students from Simmons University down to Nicaragua for two weeks to live with families and do community service. Most of the students were studying nursing and physical therapy. Nursing students weighed babies, gave shots, and were even allowed to sew up machete wounds on weekends. PT students gave drop-in massage and advice sessions to older country folks waiting to see volunteer eye doctors from Connecticut. Then I started to seek volunteers from elsewhere. A Harvard medical student from a Nicaraguan immigrant family spent a summer looking at fecal samples under a microscope. Verdict: up to 80% of rural people were infected with as many as three types of parasites, causing chronic diarrhea. Their water came from hand-dug wells near animals and outhouses. I told the Sister City Project. Our first impulse was to pool our money to buy medicine. Then a doctor said: “Cure them on Monday, they’ll get re-infected on Tuesday.” The answer seemed obvious: we needed to purify the water from the well.

The 10” PVC filter we made for several years.

I began to search the web for solutions we could afford and came across a sand-based filter developed by a professor at the University of Calgary. David Manz knew that even ancient Egyptians used sand to decontaminate water from the Nile River. He developed a water-cooler-sized concrete box filled with sand and a drainage system. Manz discovered that the top layer of sand in the filter (below a standing two inches of water) slowly forms a colony of predator organisms where lots of the E. coli are trapped and eaten. Manz called his invention the BioSand Filter (BSF), and it was the centerpiece of his new Center for Affordable Water and Sanitation Technology (CAWST) in Calgary.

I was stunned: how could we make these in rural Nicaragua? CAWST was having a BioSand Filter training seminar in Danlí, Honduras, just north of Nicaragua. We sent one of our best workers, Fidel Pavón, up to Danlí. He returned to San Juan a total BSF convert. We bought an expensive iron mold for casting the BSFs in Fidel’s yard, I got a pair of grants from a Boston foundation, and we started turning out one filter each day. The best sand for the filter came from an extinct volcano called Motastepe: sifted fine and washed eight times, it was ideal for removing pathogens.

The problem was that the cement filters weighed about 350 pounds empty. It took two strong guys to lift one. We would slide them up planks to the mayor’s flatbed truck (buffered with six inches of sawdust) and drive carefully to the target village. Once the filter was moved into the house, Fidel would install the sand, give instructions about daily use (oxygen and nutrients for the bio-layer) and keeping storage buckets clean, then move on to the next family. People loved them for a while, then bit by bit they began to be abandoned, these bulky gifts from the gringos. Often people slipped over the border to pick bananas for a few weeks in Costa Rica and the bio-layers of their filters died, resulting in a bad smell, ants, and no more filter use.

Someone mentioned the Habitat for Humanity principle of “sweat equity” — when people are given something, they need to participate in the making of it. This made sense, and the change of approach came just as we started to experiment with a new model of the filter. Dennis St. John, a restless retired engineer and architect, heard about our project and our search for a lighter type of filter. One day he wrote me from Arizona and asked why we didn’t try making the filters out of 10” PVC pipes, the kind used for water projects. The next day he sent a photo of his first prototype: thin and elegant, weighing less than twenty pounds empty, with the piping on the outside. “We should field test it,” he said. “Can you come down to Nicaragua next January?” I asked. He could and joined me and our new Filter Coordinator, a former school-teacher, Antonia Mendoza. Trucking down twenty meter long 10” PVC tubes from Managua, we fabricated a dozen filters with the amas de casa (housewives) and kids of San Antonio de Bastón under Dennis’ eagle-eye. By the end, a woman could put her new filter under one arm, her baby under the under, and walk home. We tested the well water versus the filtered water: the bacterial reduction was pretty much the same as with cement filters.

This beautiful new model had one major drawback: getting a leak-proof PVC base attached to the 10” tube. Dennis used the best flexible silicon glue available, Goop, and glued the bottom of the tube to a PVC disk he had brought from the States, clamping tube and base together overnight with a set of six bungee cords. But importing two key ingredients (strong glue and flat PVC disks) ran counter to our mantra at the time: appropriate technology means solving local problems using easily available local materials. No imports!

Our current “Filtrito” based on a 5-gallon plastic bucket,
lightweight and inexpensive.

All the same, with a beautiful and inexpensive model proving a success (people loved the look), this was apparently our future. Meanwhile, in a lab at Lehigh University in Pennsylvania, an engineering graduate student named Julie Napotnik was asking radically simple questions: Why not make a BioSand Filter out of the standard five-gallon plastic buckets available in markets all over the world? Would they hold enough sand to do the job? And would they work in real-life conditions in the tropics? I invited Julie to Nicaragua to field-test her invention in San Geronimo, a distant village with gigantic ancient trees and a clear stream running right through it. She came down with another engineering grad student, Anna Murray from Tufts. The San Geronimo women were enchanted by these young American experts, who in slow competent Spanish showed them how to make a contraption that would protect their families. In subsequent years Anna and Julie returned regularly to do careful testing of the filtered water from the bucket-filters: decontamination of well-water remained, and remains, consistently high. Since then we have installed over a thousand of what we now call our “filtritos.”

I write these words on the thirtieth anniversary of the Sister City Project’s first trip to San Juan del Sur, sitting on my rustic porch, with the blue Pacific in the distance. We have been back every January since 1989. Dozens of citizens and high school and college kids from the Boston/Newton area have also been here. Four Newton families own houses here; four of my students married their Nicaraguan boyfriends. My wife and her Nicaraguan colleague founded a Free High School for Adults that has graduated a thousand students. My year revolves around the annual mid-winter trip. While still an English professor at heart, I now dream in Spanish and have befriended various Nicaraguan writers. But I can still load a water sample into a Petri dish, incubate it, and interpret the results. And in addition to the BioSand Filter project that Antonia Mendoza directs year-round, we have an ever-evolving EcoStove (with chimney) project, so people can cook with wood without filling the house (and everybody’s lungs) with smoke. We belong to the Global Alliance for Clean Cookstoves. A high point of my year is getting into the rented truck with Antonia and heading out to a new community with its own special challenges and rewards, ready to tackle thorny technical and human complications, make new friends, and just wander in the woods of Nicaragua with their 100-plus species of trees and elusive birds and sassy monkeys. What amazing luck for this old schoolmaster, who way back in the ‘80s was asked by Father Steve if he wanted to go down and “see this Revolution made by a bunch of priests, nuns, and poets.”


All images credit of David George Gullette



DAVID GEORGE GULLETTE was educated in North Carolina public schools, Harvard, UC Berkeley, and UNC Chapel Hill. A Fulbright took him to Rome in 1966, after which he taught English for 42 years at Simmons University in Boston. He was an early editor of Ploughshares (literary quarterly), founding editor of Fenway Press, and since 1989 has been Literary Director of the Poets’ Theatre. He was also a co-founder of the Newton/San Juan del Sur (Nicaragua) Sister City Project, of which he is President. He has published poetry, fiction, plays, translations from Italian and Spanish, and essays about his work in Nicaragua.


Winter 2019  |  Sections  |  Travel

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