Pilot 1 Story. Tech Team
In our area, levels of arsenic and fluoride contamination are rising in groundwater sources and are found prevalent in community water supplies. However, when it comes to mitigating this issue, low-cost appropriate treatment technologies are not readily accessible. As an organization, Caminos de Agua has used rainwater harvesting as a solution to get people off of contaminated groundwater. This solution is successful, however has limitations. By expanding our focus to groundwater treatment Systems (GTS), Caminos can have a larger reach and offer diverse solutions to people in need of safe, healthy water.
With a focus on developing open-source and accessible solutions, Caminos has spent thousands of hours researching and testing alternatives for groundwater treatment. Throughout the world, there has been a longstanding focus on treating water bacteriologically, but when it comes to other contaminants, including arsenic and fluoride, there is a lack of accessible technology. We especially see this in our region. To combat the fact that low-cost and effective solutions to groundwater treatment are not readily available, Caminos embarked on the mission to better understand existing technologies and synthesize a solution that could be locally-sourced and quickly implemented.
In the laboratory, the Caminos Tech Team worked for over five years, doing experiments with various treatment technologies related specifically to arsenic and fluoride. Efficacy of these technologies can depend a good deal on the specific conditions of regional water. Therefore, Caminos made a point of sourcing local water with diverse conditions to perform the analyses.
Working in collaboration with global WASH leaders, the team built upon the technology of bone char for fluoride adsorption and began to produce it in-house, testing and improving methods throughout the process. Meanwhile also testing a range of commercial adsorption media. Within this process, the tech team saw promising results with a granular iron-oxide, named Bayoxide. The team also collaborated on developing the lead-lag column set-up, to optimize the capacity of the adsorption media.
As the technological side of groundwater treatment was progressing, the team recognized that the next challenge was developing how it was to be implemented and what the requirements for monitoring and testing would be. Caminos recognizes that technology is never a solution by itself and it is only successful with dedicated training and community involvement. Caminos is guided by the notion that we are all agents of our own change and follows community decision making processes. Therefore, the goal of the pilot became not only to understand the technical performance of the treatment technology, but to run a full-scale operational system alongside users. With this came the opportunity to observe user interaction and sampling and maintenance requirements.
The community that initially came to mind, as a place to implement the first pilot, was a community with high levels of groundwater contamination, Pozo Ademado. Caminos approached the community about the option to work side by side on the project. After conversations regarding the details of the project, the community members unfortunately decided against involvement. The pilot would only serve a limited amount of the families and they were worried it would create conflict. In addition, due to the nature of it being a pilot, it would require more involvement than usual, to collect samples and take readings. In the end, they decided that this was not possible.
Luckily, another connection was made and a partnership moved forward to install the first pilot on a spirulina algae farm, located near the land owned by Caminos. The owner of the farm, recognizing government regulation to have limited arsenic in his product, became interested in the project in order to treat the water he used to grow his spirulina. Plans were made to install a system that would treat around 2,300 L/day of water, adjacent to his existing water lines, on the side of his existing concrete water tank The Bayoxide treatment media, housed within our locally-sourced and internally-designed PVC columns, became the base for this Pilot 1 trial.
The system works as follows. Water from the local well comes into the storage tank and is first treated by sediment filters to remove dust and debris. It then flows through two columns of Bayoxide treatment media, in lead-lag set up, to remove the arsenic from the water. After, the water is directed into a clean water storage tank, where it is pumped for use in the spirulina growing tanks. The water comes out of the system with arsenic levels below the WHO recommendation for healthy water and is ready to support the algae growth process at the farm.
After one year of monitoring and testing, Pilot 1 had successfully produced over 700,000 liters of treated water at a cost of around $1USD/1,000L . After an informative year of water treatment and analysis, the Caminos team had gained valuable knowledge of the system, it’s performance and operation. The pilot was ready to be transferred to long-term use by the spirulina farm. Since the beginning of 2020, the pilot has been continuing to produce arsenic-free water for the user and continues to be in use.
This first pilot has set the stage for future work in groundwater treatment. The next stage involves a system able to remove not only arsenic, but also fluoride, among other contaminants, at a community level.