A 330 pound concrete BioSand Filter, one of about 600 being delivered in 2008-2009. The unwieldiness of this model is a major drawback. Photo by David Gullette
Solving Water Problems in Southwestern Nicaragua
By David Gullette
In global terms, ours is the troubled century of water. Expanding populations, extreme climatic events, and threatened or contested sources of “the vital liquid” are guaranteed to cause more crises—even regional conflicts—in the coming decades.
But let us tighten the focus to the strip of land in Nicaragua between the Pacific and Lake Nicaragua, south of Rivas all the way to the Costa Rican border: here folks are paradoxically both rich and poor when it comes to access to potable water.
The port town of San Juan del Sur went from sleepy fishing village to international resort in 20 years, like Provincetown on fast forward. It now gets its water (heavily chlorinated) from the big lake, pumped through a system financed by the Spanish government. Ironically, the residual taste of chlorine, plus a widespread revulsion at the very idea of drinking lake water, means that most sanjuaneños who can afford it use tap water for everything but drinking. The bottled water business is booming.
Meanwhile, in the 33 impoverished rural communities scattered around the 250 square mile township, potable water from a tap remains a distant dream.
Most rural homes get their water from hand-dug wells. And virtually all these wells are contaminated, given the omnipresence of farm animals plus the haphazard placement of porous latrines. The water contains E. coli bacteria, as well as a range of parasite cysts. Intestinal ailments are widespread, dangerous for vulnerable infants, and hard (and expensive) to get rid of.
We in the Newton (MA)/San Juan del Sur Sister City Project (www.newtonsanjuan.org) have been working with our Nicaraguan colleagues for more than a decade on a set of interlocking water solutions: home-based purification of well water; rehabilitation of wells; installation and repair of hand-operated pumps; teaching families basic hygiene; watershed preservation (partly through reducing firewood use); and introducing sealed-unit composting toilets to replace the traditional latrines.
Our preferred method of purifying well water has been the BioSand Filter (BSF).
Invented by a Canadian and promoted around the world by CAWST.org in Calgary, the BSF is essentially a box, usually of concrete, the size of a free-standing water-cooler, filled with carefully processed sand and gravel. Contaminated well water is poured in at the top, works its way slowly down through the column of sand, and comes out of a spout, purified. Key to the process is a “biolayer” created by the permanent two inches of water above the top layer of sand, where “good bacteria” slowly form a colony: they trap and eat much of the E. coli population that passes through.
The BSF has obvious advantages: it’s cheap (about US$50 each); home-based; and requires no chemicals or electricity.
The downsides are that boxes made of concrete are extremely heavy (330 lbs. without the sand/gravel) and thus hard to deliver and move for maintenance; they also require daily use to keep the “good bacteria” in the biolayer well-fed and oxygenated. If neglected for more than a day or two, the biolayer dies and starts to stink, and the efficacy of the system is compromised. Thus the human element at the point of use is crucial. Families have to be disciplined enough to follow the “use-it-every-day rule” and keep their water storage bucket clean to avoid recontamination.
In 2008 and 2009, grants from the Boston-based Conservation, Food and Health Foundation allowed us to manufacture and install more than 600 BSFs in twenty rural communities,and to train area promotoras and village brigadistas to troubleshoot and help villagers comply with the rules of proper filter use.
In 2011, retired businessman Dennis St. John approached us with his design for a BSF made entirely of PVC (using a 10” drainage pipe for the column). For the 2012 pilot project we installed twelve of these in one community. We have been very pleased: the PVC filter weighs only 29 lbs. empty, and laboratory tests show that it removes contaminants as well as the concrete filters do. Plus, it’s elegant and easy to clean. We’ll build and install 36 more in January 2013.
Our Nicaraguan colleagues also emphasize domestic hygiene, especially hand-washing and keeping animal feces out of the yard. Particularly useful in these efforts are graphic posters made available by CAWST.org. We have also paid to have wells dug deeper and re-lined, and to have the classic “rope pump” installed or repaired.
Because an occasional well runs dry early in the year, we also focus on “how to take good care of your watershed.” Since virtually everyone cooks with wood in the countryside, we point out that stripping vegetation from around the house can actually put the water supplies at risk. We explain how, when it rains, a forested hillside is like a sponge; if deforested, it’s like a zinc roof. But people still need wood to cook. So Fidel Pavón and I developed our own model stove, which uses half the amount of wood of the typical open fire with the added advantage that its chimney rids the house of the smoke that gives mothers emphysema and children asthma. As we were building the prototype, Fidel’s wife, Luzmarina, was hospitalized with emphysema, but after we replaced her open fire with our EcoStove, her symptoms disappeared.
We’ve decided to present the EcoStoves as a reward for families who use their BioSand Filter properly. At the same time, it’s a new incentive to those who have stopped using their filters: get your filter re-installed, follow the rules, and become eligible for a stove. (Unlike the BSF program, in which we gave the filters free of charge, participants in the EcoStove program must donate sweat equity and when possible, materials such as cement, sand, and bricks, to obtain a stove.)
Demonstrably, clean lungs, clean water and healthy watersheds go hand in hand.
One obvious alternative to the use of BSFs would be to have wells professionally bored to great depths where contamination is not a problem. The issue here is cost: it’s extremely expensive to have a deep well bored, and a pump for such a well requires electricity, yet fewer than half of the villages we serve are wired. And in most villages the houses are so dispersed that piping water to each home would be an additional challenge.
But one non-electrified community did it right: Ojochal, where about twenty families live along an ascending dirt road. In 2008, the Union Church in Newton worked with local residents to take several steps toward a potable water supply. They deepened the existing, privately owned well at the top of the road that most people used and then constructed a hardwood tower to hold a 1,100 gallon water tank. They installed a set of solar panels to power a submersible pump to fill the tank and finally, they excavated a trench for a two-inch water main to run the water down the hill, with a spigot in front of each house. Eventually the mayor’s office found money to bore a deep public well. Today, all the Ojochal families have access to solar-pumped high-quality water that does not require subsequent filtration. But of course there are 32 other villages.
One other way to limit the infiltration of pathogens from surrounding soil into a well is by using composting toilets (CT). The first of our “in-house outhouses” was a twin-bin affair (one room for boys and one for girls) built next to the schoolhouse we financed in the community of Cebadilla.
Essentially our CT is a pair of tall boxes on, not in the ground. Their floors are sealed with roofing cement. A tall stack carries off water vapor and whatever gases arise from the composting process, and creates a slight updraft to disperse odors. On top of the boxes sit the roofed “throne rooms.” Because San Juan del Sur is a fishing port, we were able to modify a Vietnamese-model CT, employing a “hammock” of heavy-duty nylon fish net that holds the “biomass” in the air so that aerobic decompostion can take place. The “hammock” was filled first with layers of palm fronds, zacate (a perennial fodder grass), corn husks, leaves, and sawdust from the sawmill a mile away. A bucket of sawdust is left in each stall, and the teachers are urged to throw a handful or two of sawdust into each toilet at the end of every school day.
This system has functioned flawlessly—without strong odors or external leaks—since February 2005. Not far away is a hand-dug well that serves most of the community. The schoolyard where the well is located is livestock-free, thanks to a barbed-wire fence. As a result, the unfiltered well water registers a fairly low E. coli count, compared to similar (unfenced) wells in the region.
Our Canadian colleagues at Project Nicaragua/NicaCan have been promoting single-family composting toilets in several other rural communities in the San Juan del Sur township. They found that often families would help build their new CT and then, when the Canadians left, revert out of habit to using the old odoriferous, well-water-polluting latrine. The donors now insist that the old latrine be dismantled before the family can receive the new CT.
This sporadic backsliding points to a key issue that we who do development work must sooner or later confront, whether we work in water purification, sanitation, alternative building materials, or something as basic as making sure kids get sent to school. The point is, people are slow to change old habits, or as we say in Nicaragua, La costumbre es la ley: old customs rule. Some people will never change. I once saw a man kneel on a rock covered with monkey feces and drink directly from the creek which ran below his knees. Maybe his intestinal system had years ago adapted to the bacterial flora of the water he and the monkeys shared. Or maybe he suffered from chronic parasitosis and simply lived with it. What is clear is that an infant or toddler would almost certainly not be as immune to infection. Worldwide, 5,000 such children die every day from contaminated water. Doubtless the parents of many of these children had been warned about microbes. But as in all types of education, including public health, steady repetition and reinforcement of basic lessons is crucial. Patience is power.
Certainly, our efforts to guarantee year-round potable water for folks in our little part of the world will never have 100 percent success. But over the years we have forged partnerships between activists in Newton and numerous Nicaraguan colleagues—in the medical community, local government, civil society, village councils, and individual families—that will at least assure that la lucha continúa: the fight for clean water goes on.
David Gullette is Vice President of the Newton, MA/San Juan del Sur Sister City Project. He is author of Nicaraguan Peasant Poetry from Solentiname, ¡GASPAR! A Spanish Poet/Priest in the Nicaraguan Revolution, and Dreaming