BioCycle February 2009, Vol. 50, No. 2, p. 42
Low cost, a simple design, system reliability and social acceptance have led to installation of composting toilets in a tourist region in Ecuador.
Chuck Henry, Elena Olsen and Marcos Fioravanti
Current estimates are that 2.6 billion people in the world lack basic sanitation. The United Nations World Water Development Report (UNESCO-WWAP 2006) estimated the deaths alone associated with sanitation-related water-borne communicable diseases were about 3 million in the year 2002. Traditional collection and treatment is expensive. The U.S. Environmental Protection Agency estimates costs of $6,700/household for on-site wastewater treatment, $10,800/ household for community cluster treatment and even higher costs for large sewage systems followed by a wastewater treatment plant.
The United Nations General Assembly declared 2008 to be the International Year of Sanitation, with a goal of reducing by half the proportion of people without access to basic sanitation by 2015. Clearly this is an exceptional goal, but the question looms: How does even a single developing nation increase by half the number of people its sanitation systems serve? Traditional wastewater treatment also presents technical obstacles. Since a mechanized treatment plant is designed to run within a narrow tuning of parameters, failure in a developing country is often just a broken part, power outage or funding shortage away.
Pit latrines have been frequently mentioned as an option in developing countries. Disadvantages include danger of groundwater contamination, so they can’t be used in rocky ground or where there is a high groundwater table. Pit toilets cannot be used inside a home, and no matter where they are, new pits must replace old ones eventually.
Composting toilets, while not a miracle solution by any means, are a simple, economical and low-impact sanitation system that require no water, are usable in remote or difficult areas, can incorporate food waste and yield usable soil amendment. Institutionalizing the use of composting toilets does present social challenges, such as perceptions of odors and handling human wastes even after processing. However, these challenges are successfully surmounted when the toilets are properly designed and operated. In fact, as argued by a teacher at El Colegio Cruz del Sur in Guayaquil, Ecuador, maintaining and using a clean basic sanitation system can increase a community’s pride and sense of worth – whether that community is a family or an entire town.
DEVELOPING EL TALADRO DE LA TIERRA
As a senior project, a University of Washington (UW) student initiated a composting toilet installation in a rural area of Costa Rica in the spring of 2006, resulting in the first international demonstration. The toilet was designed by Chuck Henry (article coauthor) from a kitchen waste composter that he built, which uses an auger to move food waste from the countertop, out of the building to a flowerbed as a finished product. The idea manifested itself well, but attracted fruit flies, prompting simple modifications for the composting toilet.
Cost, portability and simplicity of use were criteria for the installation in Costa Rica. Additionally, the client wanted it transportable, e.g., no concrete. The toilet was built in a laboratory at UW, carried onto the jet, and assembled on site (including the building) in three days. Total cost was around $150, using recycled lumber from an old house. A positive reception led to formalizing the design through UW’s Technology Transfer program.
In 2007, a project was initiated in Ecuador with Sambito Co. Ltd. to design composting toilet facilities for tourists at the beaches near Guayaquil, the country’s largest city. A workshop was held in April 2007 in Guayaquil to teach employees of Sambito and maintenance staff at El Colegio Cruz del Sur how to construct and install the compost toilet system, named Taladro de la Tierra (which translates to Earth Auger, henceforth referred to as El Taladro). As part of the workshop, the system was installed at a private high school, Colegio Cruz del Sur, for use by the guards and maintenance staff. A group of Guayaquil government officials, responsible for funding the beach facilities, were invited to the workshop installation to see the system.
The purpose of the installation was to demonstrate the technology, test the operational parameters and qualitatively test the characteristics of the resulting compost prior to the beach installations. El Taladro has proven to work exceptionally well. Moisture of the finished product varied from 31 to 64 percent (average 51percent), N varied from 1.2 to 2.3 percent, and P was 0.2 to 0.3 percent. The variation was attributed to the amount of urine included. These tests suggest that conditions were quite favorable for active composting. As such, fecal coliform counts were reduced significantly (to about 1100 MPN/g) for the relatively short study period (less than one month). Future testing will monitor pathogen dieoff for the suggested four-month period of composting. Since that time, and due to the success of this demonstration, an additional 32 units have been installed near Guayaquil, and another 80 are in the process of being funded by the Guayaquil government. In Costa Rica, three units (in addition to the original one) have been built and are in use.
Keys to success of this composting toilet include: Low cost – the system can be built easily with locally available materials and by local workers; Reliability and low maintenance – it is simple to operate and easily maintained, with weekly (or less) turning, and finished compost exiting through a 12-inch diameter tube; Social acceptance – although use of composting toilets is not widely accepted, demonstrations, such as at the school, and operational units in communities, have increased its acceptability, as well as documented results of existing units.
The success with El Taladro in Ecuador can also be attributed to a series of right conditions, including local young people trained in sustainable practices and a strong desire to provide sanitation in a difficult situation. The beach community in Santa Elena County near Guayaquil, for example, has a strong tourist industry and no sewage system. Sanitation is typically provided by use of portable toilets. Because rainfall is about 4 inches/year, water is currently hauled in by truck. Flush toilets that exist, for instance in restaurants, are flushed by pouring a small amount of water down the bowl, only enough to wash down the waste. That waste is piped into the sea without treatment. There was obvious interest in alternatives, residents and tourists alike, as well as from local and state government. There are now four toilet facilities, each with seven Taladros.
Students at Cruz del Sur, where the first workshop and toilet installation took place, are required to do senior projects, often in some way helping a poor community that the school has adopted. A number of these students have chosen to help install Taladros as their senior project. One very surprising outcome of this work in Ecuador in the poorer parts of Guayaquil was dignity: Families that received a composting toilet strongly voiced their appreciation, specifically citing an increase of dignity that they now found having adequate sanitation.
The Eastside Preparatory School in Kirkland, Washington has developed a “sister school” relationship with Colegio Cruz del Sur. In June 2009, as part of a service learning project, students from Eastside Prep will stay with the students of Cruz del Sur and join them in making and installing additional composting toilets in their adopted community, taking one step towards that United Nations’ goal in the International Year of Sanitation.
Chuck Henry and Elena Olsen are High School teachers at the Eastside Preparatory School in Kirkland, Washington. Marcos Fioravanti is with Sambito Co. Ltd. in Ecuador.
February 17, 2009 | General
Improving Sanitation With Composting Toilets (Ecuador)
BioCycle February 2009, Vol. 50, No. 2, p. 42