Our group is designing a low-cost water filtration system for removing arsenic and mineral contamination from groundwater. We're looking to use a three-step system that can soften hard water, remove arsenic, and store filtered water for continual use. Our target communities are two areas of Peru, Carancas and Huatta, that have had major problems with arsenic in their drinking water. Our filter will use local materials (clay pots, wooden stands, sand, iron filings) and a novel chemical filtration process to provide safe, clean drinking water. We'd like for the filter to be usable in any community that doesn't have access to clean drinking water, and plan to produce educational materials for different age groups and languages.
This project proposes equipping rural families located in two known arsenic “hot spots” in southern Peru to acquire a simple arsenic filtration device for water used for cooking or drinking. It would do so through a pilot project in which engineers from an EWB chapter would collaborate with the Chijnaya Foundation (a U.S.-based 501c3 nonprofit) and its partner organization, the Peru-based Suma Marka nonprofit to introduce the SONO filter to homes drawing on groundwater with unsafe levels of arsenic. The SONO filter utilizes porous iron scraps, charcoal, sand and bits of brick and removes nearly all of the arsenic from well water.
This project will do two things: 1) provide relief for families known to have high arsenic in their well water and 2) serve as a pilot phase of a project that could be replicated in dozens of communities in the region with similar bedrock geology. The Chijnaya Foundation and Suma Marka have been working closely with the regional Ministry of Health for two years on a number of successful projects related to surface water and public health, and the director of the Laboratory of Environmental Health at the Ministry has identified arsenic testing as a priority for his division, and wishes to be involved in all phases of this project. The aim of the pilot project, if it is successful, is to provide a field-tested premise for scaling up the SONO filter: where the Ministry finds excessive arsenic in water, citizens will be directed to technicians who will be able to build these filters at an estimated cost of about $20 US per unit, with an estimated life of 5 years with no maintenance needs.
Arsenic exposure is recognized by the World Health Organization and agencies such as the U.S. EPA as a significant threat to human health. Long-term exposure to arsenic via drinking-water causes cancer of the skin, lungs, urinary bladder, and kidney, as well as other skin changes such as pigmentation changes and thickening (hyperkeratosis). The problem of arsenic in drinking water is not unique to the highlands of Peru and Bolivia, but it is relatively understudied in this region. The state of groundwater is of particular concern in this area because many rural communities are drawing increasingly on wells for drinking water as growing informal urban settlements contaminate streams and rivers.
Members of the Chijnaya Foundation and Suma Marka conducted preliminary well sampling in early 2009 in several rural districts of Peru where the geology indicated auspicious conditions for arsenic. In several locations, the results showed extremely high concentrations of arsenic, ranging between 60 and 900 parts per billion, (the maximum health guideline established by the World Health Organization is 10 ppb). Subsequent tests undertaken at Duke University confirmed these elevated levels of arsenic. Speciations of the arsenic indicated that the largest percent of the arsenic was in trivalent form, which is by far the most damaging form of arsenic for human health.
EWB-UC Berkeley brings together a team of more than twenty undergraduate and graduate student engineers, as well as three professional engineers as mentors, to tackle this design challenge and produce a usable, locally-sourced filter that lowers arsenic concentrations to potable (drinkable) levels, and removes water hardness that causes dry skin and irritation.