|Rural water treatment system in Puerto Rico.|
Improving Drinking Water Quality in Rural Puerto Rico with Low-Cost TechnologyEnergy efficient and easy to maintain, these systems could significantly lower rates of water-borne disease
There are estimated to be nearly 250 drinking water systems that serve small communities in rural Puerto Rico that are not under the purview of the Puerto Rico Aqueduct and Sewer Authority (PRASA). The drinking water supply in these rural communities typically consist of little more than tablet chlorinators and large holding tanks for water that drains down from mountainous streams, which is then piped into local homes. In many cases, the systems offer ineffective treatment, or none at all.
Funded by EPA Office of Research and Development’s (ORD) Regional Applied Research Effort (RARE) program—which addresses environmental science issues of critical importance to EPA’s regions— researchers from ORD, in collaboration with partners from the Region 2 Caribbean Environmental Protection Division and local drinking water systems, are building on their ongoing efforts to improve drinking water quality in rural Puerto Rico. This new project will install treatment systems that combine chlorination with ultra-violet (UV) disinfection in small rural communities.
Craig Patterson, an ORD engineer, says chlorine kills most of the microbes that cause diarrhea and other water-borne diseases. But some microbes, including Giardia and Cryptosporidium parasites, are chlorine-resistant. Emitted by specialized fluorescent lamps, UV light kills these pathogens, and others as well. EPA developed and field tested the combination of chlorine and UV treatments as a double barrier against contamination. “We plan to analyze microbial levels in the water before and after treatment,” Patterson says. “So in that sense, this project is also a verification study designed to further investigate the technology’s performance in the field.”
Patterson’s collaborator, Dr. Graciela Ramirez-Toro from InterAmerican University (IAU), in San German, Puerto Rico, says that the combination chlorine/UV-based treatment has the advantage of being cheap, energy efficient, and easy to run. With ORD’s assistance, the technology was already installed and tested in the rural community of La Sofia. As part of the current RARE project, which started June 1, 2013. IAU partners will evaluate La Sofia’s capacity to maintain and operate the treatment system, while also documenting its associated costs. “We will work with community members to help them understand the importance of proper drinking water treatment for improving health,” Ramirez-Toro says.
ORD already has a history of working on drinking water issues with IAU and other university-based collaborators in Puerto Rico. Patterson and scientists at the University of Puerto Rico’s Mayaguez campus worked together to upgrade a much larger and more resource-intensive slow-sand filtration system in the town of Las Piedras. Slow-sand filters remove viruses and bacteria from water percolating through the system. “But these systems take a lot of work to maintain,” Patterson says. EPA helped the local community take over system operation and maintenance and the community-based organization now serves as a model for similar local water systems.
According to Dr. Marie O’Shea, ORD’s Regional Science Liaison in Region 2, technologies appropriate for Puerto Rico’s non-PRASA communities need to take into consideration the limited infrastructure, resources, and expertise available in these small rural communities. “These systems should be easy to build, operate and maintain.” Dr. O’Shea says. “Ideally they should be low-cost, low-tech, fabricated with parts available on the island, and energy efficient, for example, operational via gravity or solar power.”
Patterson explains that ORD’s role is, in part, to help select the right treatment systems for the right locations in Puerto Rico. “But clean drinking water isn’t just about treatment,” he says. “It’s also about community involvement.” Our study will provide installation and initial technical support and our IAU partners and residents in the small communities will take it from there.”