Appropriate Technologies: Biosand water filters, Eco-Stoves and Self-composting latrines
For 5 years, the Newton-San Juan del Sur Sister City Project have been building and installing self-composting latrines, eco-stoves, and bio-sand filters to confront some of the communities’ greatest health needs. These simple but effective devices are built locally and distributed in conjunction with educational efforts led by the Centro de Salud, the local branch of the Ministry of Health, and Servicios Medicos Comunales, a local health clinic with a network of health workers in the communities. To date, we have installed these technologies in over 20 communities surrounding San Juan del Sur.
All three products are easily constructed using locally available products (cement, bricks, sand, gravel, quarry stone). Most people “buy” their filters, stoves and toilets by putting in a week’s labor at the Newton Workshop—or Taller—where Fidel Pavon, our technical expert and a local community leader teaches them not just what to do, but how these clever inventions work and contribute to better health and a more stable natural environment.
Biosand Water Filters - The importance of providing safe drinking to populations around the world is recognized internationally and expressed explicitly in the Millennium Development Goals which were adopted by the United Nations in 2001. The project’s approach is to provide point-of-use Biosand filters in homes in San Juan and the many surrounding communities. Invented by a Canadian working in Guatemala, the Biosand Filter is a cement vessel filled with layers of sand and gravel. Made from simple, locally available materials, and built here in San Juan, the filters work by trapping viruses and parasites in the many sand grain pores. In addition, a naturally forming biological layer of predator organisms, which grows at the top of the sand, consumes disease-causing E. coli bacteria. Contaminated well water is poured in the top and as it works its way down through the mass, 100% of the viruses and parasites and 96% of the E. coli bacteria are filtered out.
Eco-Stoves - Most Nicaraguan women cook over open fires forcing them, and the children who accompany them, to inhale unhealthy amounts of smoke each day. Little wonder that levels of asthma and emphysema are alarmingly high in rural areas. The project’s solution is the EcoStove. Made of brick and cement, it is a cooking box on legs which allows for air to flow in one end fueling the fire, up the cement tubes along with the smoke, and out of the house. It’s called EcoStove because it uses half the wood of an open fire, which means less cutting of trees in the surrounding watershed, which in turn means more water absorbed during the rainy season and wells less likely to go dry in March, April and May, before the rains arrive.
Self-Composting Latrines - The traditional latrine can best be thought of as a foul-smelling hole in the ground that injects harmful fecal bacteria into surrounding wells, especially in Nicaragua, where the soil is very porous in the rainy season, and pathogens migrate easily underground. The composting toilets from this project—in Spanish “Servicios Organicos”—use a watertight container that sits on the ground, not in it. A “hammock” made of heavy-duty fishing net holds a bed of leaves and sawdust; air is allowed to circulated around it, so the human waste decomposes aerobically (with oxygen). The result is a non-smelly outhouse that does not contaminate the environment, above-ground or below. An important complement to providing filters, is assuring that the water table remains as clean as possible. These latrines limit the human waste contamination and thereby improve the health of families using them.
Ongoing needs
In the last years, the Newton Workshop has installed over 50 such filters in the rural communities around San Juan. Recipients report markedly lower levels of illness not to mention better tasting water. The need for these filters is greater than the project’s capacity to deliver them for lack of resources.
There are still many families that need to have a cleaner environment inside their cooking spaces. The eco stove can do just that for them. The more donations received, the more eco stoves installed and therefore, more families can have healthy cooking spaces.
Amounts that can make a difference:
- A donation of $48 can purchase a biosand filter for a family, granting them clean water for years.
- A donation of $30 can purchase an eco-stove for a single family and prevent the myriad of health and environmental problems.
- A donation of $240 can purchase a self-composting latrine for a single family.
