Aug 30, 2019

From RO to Rainwater

Maintenance concerns prove critical for a treatment system at a rural school in Kenya

Maintenance concerns prove critical for a treatment system at a rural school in Kenya

In a rural area of southeastern Kenya, there is a school with more than 1,000 students that has been treating its borehole water with a reverse osmosis (RO) system designed in Texas. Well Beyond put it there, and it will never do that again.

Well Beyond is a team of engineers, hydrogeologists and technical experts in the water field, and its job is to provide technical expertise for clean water projects in developing regions of the world. It is not a nongovernmental organization, but it was created from one. Well Aware, an Austin-based clean water nonprofit, began implementing clean water systems in Kenya in 2010 and has since expanded into Tanzania and Uganda. The team’s collective experiences—through Well Aware and their respective careers—in navigating the challenges with access to clean water in some of the most remote places on the planet have provided them with a niche knowledge to support the work of well-meaning nonprofits who lack this specific proficiency. However, we have not always been so keen.

Well Beyond originally installed a solar-powered reverse osmosis system but quickly found that the prefilters were not well-suited for the level of sediment in the raw water. Later, they installed a rainwater harvesting and purification system that used solar-powered ultraviolet purification.
Well Beyond originally installed a solar-powered reverse osmosis system but quickly found that the prefilters were not well-suited for the level of sediment in the raw water. Later, they installed a rainwater harvesting and purification system that used solar-powered ultraviolet purification.

Trial & Error

Sharing our lessons learned helps other groups avoid the mistakes we made in the early years. One of these lessons came from the implementation of a customized water treatment system for the Ndatani School and its surrounding community, which were in need of clean water as they are located in a dry, remote southeastern part of the country.

As we were designing the water project for Ndatani, just two years into our work in Kenya, we anticipated a low yielding borehole. Upon weighing the risks and benefits for the school, we determined the investment was well worth the less-than-ideal output. Surprisingly, we hit a decent yield after 200 meters of drilling, and we all celebrated, until the water quality analysis results were delivered. The nitrates were almost 20 mg/L, well above the World Health Organization (WHO) standards of 10 mg/L. The most common health risk for high nitrate levels is methemoglobinemia, or “blue baby” syndrome. 

We could not allow the children to drink the water we had just made available. As a team who is committed to providing communities in East Africa with safe water, not just for the short-term, but to enable their long-term success, we were not going to walk away from this school. However, local options were limited and most were cost prohibitive. Additionally, the school had no electrical power available nearby, posing another obstacle to overcome in the water treatment system planning.

As we began to review the options, we knew we would need a customized treatment system to get the nitrates within a safe range for this school. In this specific case, the most technologically advanced system that would effectively treat the high nitrates of the borehole water was an RO system, which uses a membrane filter to remove ions and other unwanted contaminants from drinking water. 

After weeks of research, we located a shop in Victoria, Texas, that was willing to help. Together, we designed a solar-powered RO machine with as few moving parts as possible that also met the required dimensions and weight parameters. We shipped our new machine to Kenya’s main port, Mombasa, and we installed it in Ndatani. We celebrated the success, and the school began to thrive with its new technology—for a little while.

Designed in Texas, it became challenging to find replacement parts for the solar-powered reverse osmosis system in Kenya due to metric measurements when the  system began  to malfunction.
Designed in Texas, it became challenging to find replacement parts for the solar-powered reverse osmosis system in Kenya due to metric measurements when the system began to malfunction.

Maintenance Matters

We received our first call from the school about a year after the RO system was in place. Although we provided it with two years of cleaning chemicals, the school already was out. Our Kenyan project manager explained to us that they thought the system would work better if they scrubbed harder and with more solution. In response, we provided additional cleaning supplies and instructions on cleaning the system properly, and the project seemed to be back on track.

Nine months after that, we discovered the school had discontinued use of the treatment system altogether, and the students had been without clean water for several weeks. We learned that the membranes clogged much sooner than anticipated because the prefilters were not well-suited for the level of sediment in the raw water.

Despite aggressive efforts, the parts needed for the repairs on the treatment system this time were simply not available in Kenya. Similar parts were possible to purchase, but the metric measurements and other specifications were not matching up with what was needed, and any inappropriate substitutes would only further compromise our already fragile equipment.

Our subsequent team trip to Kenya included gathering supplies from the U.S. to pack and haul to East Africa. Two of our technical team members spent several days on site at Ndatani replacing filters and membranes and repairing other pieces of the system that failed as a result of the poor upkeep. The team also used the time in the community to educate a local technician on the basic maintenance required to keep the system functioning properly, educate the teachers on the importance of treating water, and educate the students on the importance of clean water.

Again, the system was back up and running. By this time, we had lost confidence in our water treatment choice, and we began holding our breath. After three years of malfunctions, expensive maintenance, and overall system downtime, we realized we had made a huge mistake and that an entire project redesign was necessary. We went back to the drawing board to find the next solution for this school.

By this time, we were well-versed in rainwater harvesting and purification, and the school had more than ample roof space. We designed a robust rainwater collection system that includes two points of solar-powered ultraviolet (UV) purification and 70,000 liters of water storage. This new system allows the community to use the treated rainwater for drinking and cooking, while supplementing with untreated borehole water for agriculture, cleaning and other non-potable water applications. 

Lessons Learned

This story has a happy ending, and the school has now expanded, accommodating twice the number of children it could before. It has gardens and dormitories now, as well, and the waterborne illness rates have fallen to zero. That said, had we implemented the raw borehole water and treated rainwater hybrid in the first place, we could have saved thousands of dollars, provided months of additional clean water, and avoided the confusion, health risks and stress for the community. 

In providing the RO system, our design did not allow for community upkeep, since it required technical expertise to service and maintain when diagnostics and repairs were necessary. The community could not take ownership of the system because they could not do anything to troubleshoot problems if and when they arose. As a whole, this system was not a realistic design for the community it was intended to serve. 

Since implementing this water system, we have completed numerous other projects that require additional water treatment before consumption is safe. In these cases, we have bypassed the more complicated systems and, instead, worked with local suppliers to install efficient yet simple solutions that the community can understand and help maintain, while still providing clean water. 

For surface and rainwater, solar-powered UV purification requires little maintenance and it is free to operate. Occasional filter and bulb replacements are necessary, but these are widely available in-country and are nominal in expense. Where we have encountered fluoride, large-scale bone char filtration has been implemented to greatly reduce the negative health effects within communities. While each of these systems still requires care and upkeep, there are far fewer moving parts and they are much simpler for the community to maintain.

Ultimately, there are so many considerations that factor into maintaining and managing a successful water project. Community training, system upkeep and maintenance, and realistic design are just a few. Deploying cutting-edge technology requires thorough consideration of a culture as well as sourcing when working in international development. That does not mean, however, that technology cannot be used properly and be highly effective. Fully understanding not just what is available in the region of work, but also the cultural adoption probabilities and level of education needed to support the technology long-term, is essential in predicting success.

This is why, with the knowledge we have accumulated over the years on challenging projects, as well as our earned comprehensive understanding of community needs and potential, we have developed our own technology that is realistic, simple and appropriate for the people and communities with which we work. 

We call this technology The WellBeyond App. It provides users in a community with in-hand and onsite troubleshooting for their water systems, monthly and quarterly maintenance checklists, and further knowledge of their water source. We have found that this technology, partnered with our stakeholder training and continued partnership with communities, expands the lifetime of each system and provides the communities with the tools they need for overall success. 

About the author

Sarah Evans is the founder of Well Aware. Evans can be reached at [email protected] or 512.200.7312. 

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