Kara Nelson on Aspirational Technologies and the Sustainable Development Goals

In 1990, at the age of 20, Kara Nelson found herself in a refugee camp in Zimbabwe, just months before the independence government lifted a 10-year ban on land redistribution. The UC Berkeley biophysics student was taking a gap year to see what life was like as a non-student, and the realities of what she chose to see hit her hard.

“For six months, part of my work was with refugees from the independence war who were living in an informal settlement just outside the capital city of Harare. I became exposed to the fact that they didn’t have access to any type of basic infrastructure we take for granted in the United States, including water and sanitation.”

Nelson, now a professor of civil and environmental engineering at UC Berkeley, didn’t realize then that water and sanitation would become the focus of her career. Yet when she returned to campus, she shifted her coursework toward more applied science and took classes in African American and peace and conflict studies, while looking for opportunities to connect the science she was doing to the issues she cared about. She came to realize that engineering had the set of tools for applied research that could address critical infrastructure challenges in the developing world.

At University of Washington, while earning a M.S.E. in environmental engineering, Nelson looked for classes on the intersection of development and engineering but they didn’t exist. So she created a summer class on water and sanitation in low-income countries with a group of fellow students and a few professors. The experience further confirmed her interests. And she told herself she would pursue a PhD only if she could do dissertation work outside the U.S. Although it took Nelson several years to put together the funding, research, and logistical pieces, the UC Davis PhD managed to spend 20 months in Mexico as part of a research group at the National Autonomous University of Mexico, exploring low-cost, low-energy wastewater treatment systems.

“In Mexico, I developed a contextual understanding of the similar challenges that low-income countries confront and how the problems change based on local drivers and conditions,” said Nelson. “The barriers to solving water and sanitation problems around the world are huge, and they can’t be surmounted with just money.”

Nelson recounted this from her office in Davis Hall, where she has a bird’s eye view of the San Francisco Bay, framed paintings of water scenes, and photos of her two sons. Nelson may be a leading scholar on global water and sanitation research, with more than 90 journal papers to her name and a resume that extends 23 pages, but she does not boast her achievements. She speaks in a measured cadence that indicates a habit for meticulous thinking. Among her recognitions are a Presidential Early Career Award for Scientists and Engineers (2003), a National Science Foundation CAREER Award (2003), an Award of Merit from the Water Environment Foundation’s Disinfection Committee (2011), and a Fulbright Fellowship in Colombia from the US Information Agency (2014).

Close to 30 years in water, sanitation, and hygiene (“WASH”) research have taken the professor from Oregon to India, Kenya, China, Ghana, Panama, back to Mexico, and around the United States. These time and travel commitments have made her wise as well as careful about how to make WASH services affordable and environmentally sustainable. As a new professor, she participated in a project in Mexico teaching rural communities how to build their own water treatment devices with locally available materials. This was in line with the philosophy of “appropriate technology,” an engineering approach popularized by German economist E.F. Schumacher that advocated human-scale, decentralized, and often village-based technologies for poor communities.

“This sounds like a great idea,” explained Nelson, “but who wants to spend every week for a month building a water treatment system for your house when you’ve got other priorities?”

Nelson advocates “aspirational technology,” the idea that development engineers like herself should be designing not for poor people, but for people. “Aspirational technology is what people want for meeting their drinking water or sanitation needs,” she explained. “They want it to be exciting the way a smartphone is exciting—something you are proud to share with your neighbors and in-laws and make you feel you’re creating a better world for your children. One of the shortcomings of the appropriate technology movement is that it was sometimes perceived as designing technologies for poor people, as if they were different than technologies for rich people and that poor people had different aspirations. They don’t.”

Nelson adds that these solutions, even if they are aspirational, must not require implementation and maintenance from individual households. A shortcoming of many appropriate technologies is that they rely on low-income households to, for example, purify their own water or safely remove human waste from their households, when this is not something expected of people in the Global North. Nelson advocates that when engineers design technologies—whether for densely populated neighborhoods in Bangalore or small towns in California’s Central Valley—they must think of a whole package of household services at an affordable cost.

Increasingly, Nelson’s applied research is focused on hybrid solutions to water and sanitation in industrialized and developing countries. That is because in developing country cities, centralized systems will likely never meet universal water and sanitation needs—and in developed countries,  the large, centralized, infrastructure-heavy systems are not adaptable enough to be environmentally sustainable.

Through the U.S. National Science Foundation Engineering Research Center ReNUWIt (Reinventing our Nation’s Urban Water Infrastructure), where Nelson leads the engineering research thrust, she is studying approaches to recycle wastewater in buildings to conserve both water and energy. Another project, in Kenya and started with her former graduate student William Tarpeh, involves recovering nutrients from urine for fertilizer. Nelson is also a leading expert on intermittent water supply, a ubiquitous problem in developing countries, in which drinking water pipes deliver water only periodically. And yet another project involves turning wastewater back into drinking water through a series of advanced treatment steps, with applications for Southern California and other water-scarce cities.

Nelson is also focused on using recycled waste water to irrigate food crops—both in the U.S. and in developing countries—because the looming food crisis is tightly connected to the unfolding environmental crisis. She explains that many of our food systems are not sustainable due to the runoff of fertilizer, which is polluting surface water and in some cases ground water. Nelson is convinced that across the globe hybrid water and sanitation solutions can improve livelihoods and reduce environmental pollution.

“In industrialized countries, we have great opportunities to offset more pristine waters by using recycled water to irrigate food,” she said. “In developing countries, about 10 percent of the world’s food is irrigated with wastewater, which allows farmers to increase their productivity, but it’s inadequately treated so it exacerbates public health problems.”

Nelson is the rare full professor under 50 who pursued doctoral work in engineering solutions for low-income communities and has made it a continued focus. As a result, graduate students have been flocking to UC Berkeley to follow in her footsteps. They are among the first cohort of “development engineers”—engineers who pursue interdisciplinary technological interventions in low-resource settings.

Nelson’s development engineering PhD students who have gone on to academic careers include: William Tarpeh, an assistant professor of chemical engineering at Stanford University whose Kenya-based work focuses on extracting nitrogen from urine for producing liquid fertilizer; Emily Kumpel, an assistant professor of civil and environmental engineering at University of Massachusetts, Amherst, whose work focuses on water quality monitoring in Sub-Saharan Africa; and Andrea Silverman, an assistant professor of civil and urban engineering at New York University, who studies low-cost wastewater treatment in sub-Saharan Africa. In the NGO sector, she has mentored: Fermin Reygadas, executive director and co-founder of Fundacion Cantaro Azul, a nonprofit that develops and implements point-of-use ultraviolet water disinfection solutions in Mexico; and Ashley Murray Muspratt, founder of Pivot, a dual sanitation and renewable fuel company in Rwanda.

Said Nelson: “I feel strongly that the field of development engineering has to grow dramatically if we’re going to impact the development challenges around the world. Right now, we have the vast majority of our researchers at top universities focusing on issues that are important but often not the biggest priorities for the world’s low-income populations. If we’re going to make progress on the Sustainable Development Goals, we need many more researchers in the science and technology fields to be working on problems that people in low-resource communities face.”

Nelson is busy these days. In addition to her research and teaching commitments, she is the Associate Dean for Equity and Inclusion for the College of Engineering. In this role she is leading initiatives to diversify the student body and faculty in engineering, such as the Advancing Faculty Diversity Initiative and the pipeline program NextProf. Another major emphasis is improving equity and climate across the college so that everyone has the support they need to reach their potential.

She said what continues to motivate her in the classroom is helping students think about water and sanitation from a systems perspective—connecting the technical and societal pieces and showing how engineers need to be working in teams that have expertise in public health, agriculture, energy, and policy. Along with Research Engineer Dr. Jennifer Stokes-Draut, she developed a popular class in 2017 called “Water Systems of the Future,” which aims to provide tomorrow’s water leaders with the skills needed to overcome barriers to innovation in the risk-averse water sector.

“We all aspire to improve livelihoods, so we should be designing technologies that truly meet people’s needs and expectations,” said Nelson. She paused to carefully consider her words: “I’m a techno optimist. I think our ecosystems are in crisis. But I do think technologies will help us get out of the mess that we’re in, if we can work together to transform our institutions and political will.”

—Tamara Straus

“Imagining the Future Helps Us Engineer Toward that Future”: A Q&A with Will Tarpeh

When Will Tarpeh was an undergraduate at Stanford University, he didn’t know if it was possible to be a research engineer who works in the developing world. His global interests started in high school, when he learned that more than 2 billion people lack access to adequate sanitation. And they expanded throughout college, as he studied chemical engineering and African studies and interned at Sarar Transformación, a Mexican nonprofit focused on sanitation. “That’s when I got interested in ecological sanitation,” he said, “which is just the idea of using waste as fertilizer.”

Tarpeh, now an assistant professor in chemical engineering at Stanford, says his professional turning point happened at UC Berkeley in 2013, the year the Development Engineering program started. The Blum Center sat down with Tarpeh to learn more about his views of Development Engineering and how his research combines electrochemical engineering, global sanitation, and resource recovery.

How did Development Engineering shape your academic work in global sanitation?

It was extreme serendipity. Development Engineering started the year I got to Berkeley and made a lot of things possible. It gave me a formal structure—having a chapter in my dissertation that was explicitly about Development Engineering and about my sanitation work in Kenya. If it weren’t there and if I hadn’t gone to Berkeley, I might not have explored this part of my academic identity in as much detail. Now it’s such a crucial part, I can’t imagine being an academic without it.

What else drew you to Cal?

I wanted to work with Professor Kara Nelson, because she has a process engineering focus for achieving sanitation goals. She had a Gates Foundation grant that was part of their Grand Challenges exploration, and she and a post-doc were working on the idea of using ammonia from urine to disinfect feces. I tagged along and went to the Gates Foundation’s Reinvent the Toilet Expo, which was my dream at that time. I got to see all these cool toilets, and realized there was a large community of academic researchers who shared my interests.

How did your own research develop?

My first year in graduate school I reviewed journal papers and focused on unanswered questions. That’s when we landed on urine and recovering nitrogen. We chose urine because there were lots of motivations for separating out urine and feces. And from a chemical engineering perspective, we thought nitrogen from urine could be useful because nitrogen fertilizers are central to modern society—they’ve helped feed a growing population. We focused on what we could borrow from other subfields, such as the extraction of nitrogen from wastewater in the U.S., and also on what we could dream up on our own to address sanitation access.

How do you see your academic contributions?

My first paper as a PhD student compared materials that adsorb or concentrate nitrogen in urine. We compared four different adsorbents. Then we took the work to the field and published it in the Development Engineering journal—which meant characterizing the technology in lab, bringing it to the field, and in between looking at the operating and design parameters to show the trajectory as a contribution. Another contribution is in electrochemical nitrogen recovery. Electrochemistry and wastewater treatment have met in earnest over the past decade or so. I’ve been part of the first group of people to apply electrochemistry to urine and to extract nitrogen in a new way we call electrochemical stripping. It’s set some records in terms of nitrogen recovery efficiency and resulting energy efficiency.

You said in a previous interview that “a lot of the solutions to the world’s most pressing problems are in the minds of children who are simply preoccupied with survival.” Why are children a place to understand the world’s grand challenges?

Grand Challenges are really interesting because they are descriptive in nature. Through them, academics, UN representatives, and others try to describe a reality that millions of people experience. But I think the expertise really lies in the communities who experience the problems. We as scientists can try to lend our technical expertise in other communities—but the people who live in those communities are the real experts. That’s how I approach my work. This comes in part from growing up in a low-income household in the U.S., and knowing that resource-constrained communities have valuable skills and life experiences to solve their own problems.

How new is the field of Development Engineering?

 It’s not new in some ways. People have been doing this kind of engineering for as long as there’s been inequality. What’s new is that we’re studying how we do it and thinking about better ways to do it. Ten years ago, it was news to people that you need to engage the community when you design for it. It really was. We would learn about implementation failures all the time—and be surprised that engineers didn’t remember to ask people about their sanitation needs and, as a result, the new toilets got turned into closets because they had roofs. Now, I see the frequency with which that kind of thing is reported going down, which tells me there’s value in the Development Engineering enterprise. It formalizes things in a way that engineers who don’t focus on development can appreciate.

How important is field work to Development Engineering?

It’s a crucial site of learning. Going back and forth into the field has been extremely valuable to my research. Maybe the traditional model of humanitarian engineering was: you develop something in the lab about a problem in a developing community; you say, I have an answer for that; you characterize it in the lab; and you go out and say, here it is. But then you realize you were designing for constraints that didn’t reflect reality in the community. Development Engineering is about iterating. Over the course of my PhD, I went to Kenya and worked with Sanergy. That’s when I realized they were collecting urine but not yet creating value from it. Then I tinkered in the lab on the urine research, and spent the next four years going back and forth to see what worked and made adjustments, which allowed for the rigorous study we expect in academic communities.

 Is being a Development Engineer a liability in academia?

I don’t think it is the liability it was five or ten years ago. It’s attractive now to do Development Engineering because of the huge impact you can have. Another part of this is students are demanding training to try to solve development problems. I have engineering students who say global sanitation really gets them moving and motivated. From a disciplinary perspective, Development Engineering is one of the ways we stay relevant to our students and to the Grand Challenges that people are facing around the world.

Are you seeing more academic engineers like yourself who do applied research in developing countries?

I do feel there’s a generation of professors tying loose ends together and thinking about ways to leverage skill sets that are no longer within one discipline. Alice Agogino always talked about the wicked problems that refuse to be classified in one silo and that demand multiple approaches. Many professors now have multiple skill sets and are oriented toward solving wicked problems. I feel I’m part of this, combining electrochemical engineering, global sanitation, and resource recovery.

Do you think it’s significant that most of your mentors have been women?

Yes, and that was a recent epiphany. After Berkeley, I did a post-doc at University of Michigan, where I also was advised by two women—Nancy Love and Krista Wigginton. Female professors have impacted me, particularly by seeing the extra obstacles they have to go through and the strategies they use to succeed. Being supportively mentored by advisors who are different than me has prepared me to support students from diverse backgrounds in my own career.

How do you advocate for STEM inclusion and equality now that you’re a professor?

I recommend students and colleagues for awards, formally by writing recommendation letters and informally by suggesting people for collaborations and so on. Also, being a black male, I try to serve as a role model for students. At Stanford, I give lunch talks with minority or under-represented students. It doesn’t take a lot of time and it could be a high impact intervention for one of them. I also work to design impactful programs. Kara [Nelson] and I were involved in the Graduate Pathways Symposium at Berkeley for underrepresented minorities to apply to grad school. I also make sure when I work in Kenya, I give author credit to the local researchers on my academic papers.

 When will we achieve global sanitation?

There are some estimates that low and middle-income countries are not going to fully address the problem by 2050. One argument is that we won’t get there because of the barriers to creating centralized wastewater treatment facilities. But there are other options, namely resource efficiency. A paper I’m working on argues that if we take resource recovery one step further and bake sustainability into every process we do, we can minimize the inputs for everything we produce. The paper encapsulates the idea of the circular economy, of resource recovery. Of course, being a urine researcher, I believe separating urine has a role to play in that. I believe imagining the future helps us engineer toward that future.

—Tamara Straus