Panabaj and La Cumbre Elementary Schools were selected due to unusually high levels of E. coli and low levels of chlorine in their water supplies, as well as high rates of water-borne diseases within the student population.
If this is your first time hearing about biosand filters, here’s some quick background:
They came about in the early 1990s as a way to bring cheap, effective, and easy to use water purification systems to the developing world. Rather than going directly from water source to distribution tank, water is diverted into a plastic or cement mold, where it then passes through a number of biological and physical stages, each one intended to either trap or consume potentially harmful material. After it passes through the filter, water is rerouted back into the distribution tank and then out to the community. Since biosand filters have become a common part of international WASH practice, a number of studies have shown correlation between their use and decrease in diarrheal diseases in recipient communities.
According to Professor Erickson, biosand filters are particularly well suited to communities around Santiago because the filters require minimal initial investment and are capable of removing pathogens and solids quickly enough to meet the daily needs of an entire school.
Better still, upkeep is minimal. Once flow from the filter begins to slow down, teachers only have to open the plastic top, pour in a gallon of unpurified water, and swirl the filter’s top layer in a circular motion. It takes a maximum of five minutes.
From our end, it was a pleasure to work with such a competent and well-intentioned group of people. Because of them, students in Panabaj and La Cumbre won’t have to struggle nearly as much with the waterborne illnesses that afflict so many other students around Santiago.
Now it’s time to think about potential projects for next year. As always, we'll be sure to keep you in the loop!