Socorro, a village of 450 people, is located in the Bocacosta region along the volcanic slopes of the highlands in southwestern Guatemala. The area is a rich agricultural region for coffee and ethnohistorically for cacao. From 1887 through 1946, the town was administered by a German coffee company, which built the existing infrastructure, including the spring retaining wall. Despite the village's proximity to a major international highway, infrastructure is severely underdeveloped. A survey of the village reveals that few have latrines or other waste disposal systems, and in most cases the waste is channeled toward the river. This river also serves as a drinking water source for the approximately 75% of the village that utilizes it. The other 25% have short, usually unlined earthen wells of 3-5 meters in depth. Approximately 5 years ago, the community of Socorro began to organize to address some of these development needs and formed a citizens' council. Due mostly to community labor, most homes now have piped river water, which is used for drinking, cooking, and washing. However, this water is not potable.
In 2006, members of Socorro formed an informal committee that focused upon improving their community's water systems. Paulino Calva, our community contact, is head of this Socorro water committee, known as El Consejo Promejoramiento Para Agua. Their two main concerns were the current water treatment and drainage systems.
In 2007, Wuqu' Kawoq (http://www.wuqukawoq.org/), our NGO partner, began medical clinics in Socorro. A partnership was formed between the committee and Wuqu' Kawoq to find a source of clean water. Founder Dr. Peter Rohloff contacted EWB-UIUC (www.ewb-uiuc.org) in fall 2007 and requested that we design and build a potable water distribution system.
The need for the project is evident. Microbiological surveys routinely show high levels of contamination in river water used for drinking. Decontamination by boiling is economically and logistically impossible because burnable wood is expensive and not abundant. Wuqu' Kawoq has routinely seen a very high prevalence of acute and chronic diarrheal illnesses, as well as soil-transmitted helminthes infections and subsequent malnutrition. They routinely find high levels of giardiasis, amoebiasis, and round worm infections on fecal exams. In the first months of winter rains, diarrheal rates exceed 75% of the child population. Efforts have been made to solve these problems medically, but a more sustainable solution is required. Chlorination has not been effective due to cultural reservations, such as dislike for the taste and failure to be compelled by its efficacy and necessity. Boiling water is not effective due to the high cost of firewood, and attempts to educate the community regarding sanitation measures have thus far been largely ineffective.
Wuqu' Kawoq had identified as a potential water source a natural spring about 150 m from the center of the village. It is located slightly uphill from the village and, more importantly, uphill from the contaminated river. The spring's landowner was willing to sell the property prior to our original site assessment in January of 2008. Shorty after the return from the site assessment trip, the spring was sold. During the fall of 2008, we started development of a second design involving water acquisition from the nearby Chichoy River, centralized water treatment, and subsequent distribution to the homes in Socorro. The design included an intake, sedimentation, roughing filtration, slow sand filtration, primary chlorination, and the application of residual chlorine to keep the treated water clean as it goes through the distribution system.
Following the assessment trip in March 2009 and heading into the summer of 2009, the community leaders were becoming discouraged by the lack of progress of the water project. Wuqu' Kawoq requested that we not travel to Socorro over the summer of 2009 because because each trip raised the village's expectations, but nothing was delivered. To survey another site for the centralize treatment system or to identify another spring source to use would take another site assessment trip plus additional time to redesign and implement the system. Therefore the project team decided to change the focus of the project to Point of Use (POU) water treatment to treat the contaminated water that was already being piped to Socorro. To qualm the uneasiness of the community leaders, the project team wrote a document comparing various POU treatment options along with our recommendation that one of the options analyzed, the construction of concrete biosand filters, be implemented during fall 2009 and spring 2010. We submitted to the report through Wuqu' Kawoq. The NGO discussed the possible options with the community and replied that the village would be willing to proceed with the implementation of concrete biosand filters.
Implementation of the filters occurred from December 2009 to June 2010. In total, around 90 filters were successfully implemented throughout Socorro. Additionally, two social workers (employees of Wuqu' Kawoq) were trained to educate members of the community about the filters. A monitoring trip was taken during winter of 2010 and 2011 that confirmed that the majority of the filters were in use and functioning properly. Subsequent trips will continue to reinforce proper filter usage, sanitation, and hygiene.
Additionally, in April 2009 we were awarded the EPA P3 award for our proposed research into the use of iron oxides in biosand filtration to improve virus removal. Ungalvanized iron nails would be added to the sand media. As the water passes through the biosand filter, the iron nails would be exposed to the dissolved oxygen in the water and would rust. The iron oxides that are generated are composed of adsorption sites to which the viruses would attach. As the adsorption sites are filled, the iron oxides would fall off the iron nails exposing new iron material. This newly exposed iron would rust, creating new iron oxide adsorption sites for further virus removal. The process passively regenerates itself to indefinitely remove viruses from solution. The iron oxides are a precipitate and would be caught in the sand media once they fall off the iron nails, and therefore would not appear in the biosand filter permeate. The research was originally designated for the use in the slow sand filters in the centralized water treatment system, but since then it has been adapted to biosand filters. Future plans include comparing the function of the iron-amended filters to the sand filters already in use in the community. This research effort is in collaboration with the Universidad del Valle de Guatemala (http://www.uvg.edu.gt/).