Access to safe water is a right, not a privilege. This is underscored by the United Nations’ 2030 Agenda for Sustainable Development, where goal 6 is to ensure access to water and sanitation for all. Clean water for drinking is a critical necessity for life, and also facilitates good hygiene, which are both important for disease prevention and management. However, at least 1.7 billion people worldwide use a drinking water source that is contaminated with faeces (WHO, 2022), and 2 billion people lack access to basic hand washing facilities (WHO, 2023). Unfortunately, children in low-income households in subtropical regions are most affected by poor water quality, with the highest rate of waterborne disease.
Today, new technological advancements host the possibility of addressing this issue. Among many developments in the field of water treatment, ultraviolet (UV)-based water disinfection stands out as a superior purification method. This type of disinfection employs UV light to destroy DNA and RNA, rendering it highly effective against many types of microorganisms. UV disinfection is known as the healthiest form of disinfection, as it does not require any chemical residuals or additives. Furthermore, a single UV purification system is a long-term water quality solution, in comparison to filtration-based methods which require continuous maintenance to remain effective.
As an organization with skills and expertise in UV technology, the International UV Association (IUVA) has created a task force to work towards advancing the UN SDG goals. This task force includes academics, members from NGOs and volunteers, and has the overall objective of providing support to projects that include the use of UV technology to protect public health and the environment in low- and middle-income settings.
As a part of this task force, academics across the world have been deploying UV-based water disinfection technologies in dozens of countries worldwide (Figure 1). Although successful in improving public health and access to safe water, these initiatives faced significant challenges related to 1) maintenance, 2) longevity and environmental concerns, and 3) energy consumption. Many UV lamps demand frequent cleaning and servicing by specialized technicians, which poses a significant logistical challenge in remote communities. Furthermore, UV lamp efficacy declines sharply over time, resulting in a short effective lifespan. These lamps also contain mercury, which may contaminate the environment. Finally, UV lamps demand a significant amount of energy, which is often infeasible for remote, off-grid regions. Together, these issues render UV lamps too costly to provide sustainable, long-term water quality protection in remote communities.
One such community lies in the heart of Kenya - Nyamesocho. This village is home to Dr. Paul Nyangaresi, a postdoctoral researcher in the laboratory of Dr. Sara Beck at the University of British Columbia. Growing up in Nyamesocho, Dr. Nyangaresi is deeply familiar with the community’s daily struggles to access clean water. Boreholes, streams, protected springs and harvested rainwater are the most common sources of water used for cooking and drinking. However, these sources suffer from severe contamination. Worms are frequently present in harvested rainwater, and high levels of E. coli and coliforms contaminate all water sources (Figure 2). As a result of a lack of access to clean, safe water, there is an extremely high burden of waterborne disease amongst the Nyamesocho residents, including typhoid, dysentery, and cholera.
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Challenges in water access are particularly evident at Rianyabayo Memorial Academy, a school within the Nyamesocho rural community, which serves about 363 students (Figure 3). Similar to the households in the Nyamesocho rural community, the school lacks access to clean water. The nearest water source is a protected spring, located approximately 0.5 km away from the school. Each day, 40 school children as young as 10 years old spend 2 hours fetching water from this spring, each making 3 trips back and forth (Figure 4). This equates to 20% of their learning time being spent on water collection, a sacrifice no child should have to shoulder. In spite of the laborious efforts made to access water from the protected spring, this water is still heavily affected by bacteria and parasites. Growing up, Dr. Nyangaresi was one of these students participating in the daily water collection routine. Now, as a postdoctoral researcher at UBC, he returned to his home, equipped with the newest innovations in water purification to improve the quality of life for children in his community.
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Dr. Nyangaresi and Dr. Beck aimed to provide clean and safe water to the children and staff at Rianyabayo Memorial Academy. However, this endeavour is complicated by the lack of electricity at the school. As such, the UBC team turned to a UV light emitting diode (LED) system, which could be powered by locally available solar panels. UV LEDs circumvent the maintenance challenges of traditional UV mercury lamps, as they do not require cleaning and frequent servicing. They also do not contain mercury, preventing environmental contamination. They also boast a much longer effective lifespan than traditional lamps, and utilize significantly less energy, rendering them ideal for application in many remote settings.
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Harvested rainwater was selected as the best source for the project, as this region receives abundant rainfall throughout the year. Most importantly, the harvested rainwater was found to have a higher UV transmittance (UVT) than water from the protected spring, borehole, or stream (Figure 5). However, there were a number of challenges related to its use. Rainwater is harvested as runoff from the rooftop, which is made of galvanized corrugated iron sheets. As a result, harvested rainwater is contaminated by dirt from the rooftop, including bird/animal droppings, tree leaves, and dust. Raw harvested rainwater was found to contain visible worms and have an unpleasant odor, especially after storage (Figure 6). Additionally, when harvested rainwater sits undisturbed for long periods of time in the storage tank, it creates a high risk for microbial growth.
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To increase the UVT further, harvested rainwater is filtered by a mosquito net, which crudely filters large debris. The water is then run through layers of locally-sourced biosand/charcoal for filtration, which removes suspended particles, reducing the overall turbidity. Using gravity, this filtered water then flows into a single point-of-use faucet, where it is treated by a 265 nm UV-C light. This pilot project, completed in March 2023, was successful in providing some purified water using a rainwater source and a UV LED disinfection system (Figure 7).
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However, this project faced one major challenge, related to the capacity of the UV purification system. The reactor used has an extremely low flow rate of 2.8 LPM - barely an adequate amount for hand washing. By comparison, a typical North American faucet has a flow rate of 8.3 LPM. This minimal flow of clean water at a single faucet is not sufficient to provide a reliable supply for handwashing, drinking, and cooking to the hundreds of students and staff at Rianyabayo Memorial Academy.
To augment and improve the supply of clean water at the school, the UBC team undertook a second, larger project, with the goal of providing an adequate supply of clean water for Rianyabayo Memorial Academy. They approached Dr. Ted Mao, an internationally recognized expert in UV water disinfection and president of the IUVA, in search of partners for this project. Dr. Mao connected the UBC team with Clear Inc., a Canada-based company specializing in UV water purification systems. In this case study, we demonstrate the utility of such a partnership to deploy next-generation UV LED water purification technologies in remote communities, such as Rianyabayo Memorial Academy.
Together, the UBC team and Clear determined that Rianyabayo Memorial Academy required a different type of UV LED system to address the challenges faced in the pilot project. A novel UV LED system, pioneered and developed at UBC, utilizes a patented lensing system to concentrate and direct UV light from an LED through the water column. This allows for a much greater flow rate with higher disinfection levels than other existing UV LED products. Additionally, this technology requires less maintenance overall, reducing costs. It also offers the advantages of increased robustness, longer lifespan, low heat generation, stainless-steel housing and small size. Importantly, this particular system has extremely high energy efficiency, making it ideal for solar-powered applications at the school, as it can operate effectively with smaller solar panels and batteries.
As one of the world’s first distributors of this novel technology, manufactured by Acuva, Clear funded and donated the technology for this project. Dr. Nyangaresi returned to Kenya and oversaw the installation of the new UV LED system over the course of four months, personally handling many aspects of the process whilst also leading the overall effort. As this new UV LED system can purify a much greater flow rate of 35 LPM, it was installed directly downstream of the filtration system, upstream of 8 different POUs (Figure 8). With this tenfold increase in flow rate, the updated UV LED system is able to exceed the daily needs of all 363 students and staff. This new system maintains a UV dose well above 16 mJ/cm2, and has over 9000 hours of LED life. This project had the added benefit of providing electric lighting in the school, powered by excess solar energy from the rooftop solar panels.
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Microbiological testing shows that the biosand treated water tests positive for E. coli, but is free from these bacteria after UV LED treatment (Figure 9). This demonstrates the success of the project, which has a number of positive outcomes:
To assess the success of the project from the perspective of the local community at Rianyabayo Memorial Academy, Dr. Nyangaresi conducted a survey amongst teachers, parents, and staff at the school.
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Before implementing the UV water treatment, a significant 65% of respondents rated the school's water quality as poor (Figure 10a), which reflects and highlights the severe health risks faced by these children. After the project's completion, an impressive 95% of respondents rated the water quality as excellent (Figure 10b). This significant improvement not only alleviates the disease burden from poor water quality, but also frees up valuable time previously spent fetching water, allowing these students to focus more on their education. Importantly, this project reduces the trauma of waterborne illness within the community - no child or family should have to face the burden of losing loved ones to preventable diseases.
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The incredible life-changing impact of this project did not go unnoticed. Dr. Nyangaresi was awarded the prestigious Mitacs Innovation Award, recognizing his pivotal role in spearheading this transformative initiative. This accolade highlights the power of collaboration between Canadian technological innovation, academia, and industry to drive meaningful change. At the award ceremony in Ottawa, Canada, Clear’s CEO, Ron Blutrich, proudly joined Dr. Nyangaresi to celebrate his remarkable achievement (Figure 11). Reflecting on the success of the project, Dr. Nyangaresi emphasized the urgency of action, declaring to Ron, “We’ve collected enough data. Now it’s time to just do it!” Clear is eager to continue to partner with the UBC team, the IUVA, and other groups on future humanitarian projects to bring clean and safe water to underserved communities worldwide.
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This case study describes the first deployment of UBC's patented UV LED technology in a remote community setting. This technology represents the best known solution to combat the challenge of global waterborne disease. The success of this project shows the immense potential for UBC's technology to scale up the efforts towards UN sustainability goals to provide clean water for all. Here, we show that improvement in water quality is more than just enhancing public health; it also saves valuable time and alleviates a psychological burden - empowering entire communities to thrive and grow towards a healthier, brighter future.
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