William Tarpeh
William Tarpeh meets you with an easy warmth. In his Stanford lab he carries himself with a quiet sense of joy, as if the work around him is a puzzle he never tires of turning over. Beakers, tubes, and small electrochemical rigs surround him. The place hums with experiments, yet he seems calm in the middle of it all. There is a spark in his eyes that suggests he still cannot believe the world lets him do this for a living.
He grew up in Virginia and went through Thomas Jefferson High School for Science and Technology, a place packed with restless young engineers. At Stanford he studied chemical engineering and picked up a minor in African studies, drawn to the way science intersects with social realities. He pushed deeper into environmental engineering at Berkeley, where he earned both his master’s and his doctorate. Those years shaped the questions that now define his career. How do you take something society ignores and turn it into a resource. How do you build systems that reclaim value from the streams that disappear behind pipes and treatment plants.
His specialty is wastewater, though he talks about it in a way that makes it feel like a living system. He studies the chemistry of urine and industrial effluents with the precision of an engineer and the curiosity of someone who enjoys figuring things out from first principles. Nitrogen, ammonia, disinfectants, valuable compounds. His lab develops ways to extract them and convert them into usable products. Fertilizer that can support local agriculture. Disinfectants that can be made on site. Tools that could give communities more control over their own resources.
The devices in his lab look deceptively simple. Small reactors. Tailored membranes. Electrochemical cells that shepherd ions along clean paths. Beneath that simplicity sits an enormous amount of thinking. He designs systems that can work in the real world. Not just in ideal lab conditions, but out in the field, where water chemistry shifts, maintenance is unpredictable, and budgets are tight. His team tests these technologies in California and abroad, measuring how they behave under pressure and how they might scale.
Talking with him, you sense the way he balances rigor with optimism. He lights up when describing the moment an extraction method achieves a clean separation or when a pilot system produces its first useful product. His excitement is infectious. You can almost see the chain of possibilities expanding in his mind. He rarely talks about accolades, though he received a MacArthur Fellowship in 2025. That recognition captured something real about his work. It is inventive but firmly rooted in practical needs. It aims to make life better for people who rarely see the benefits of advanced engineering.
Photographing him reveals his mix of calm and curiosity. One moment he leans into the science with total focus. The next he lifts his head and breaks into an amused smile. He gives the impression of someone who honors the complexity of the world but still approaches it with a kind of delight. The lab around him becomes a landscape of small mysteries waiting to be solved.
William Tarpeh is reshaping how we think about waste. He treats it not as an endpoint but as a starting point. Something filled with potential. Standing with him in the soft light of the lab, you feel that sense of possibility settling in. The sense that the systems we take for granted could be rebuilt with more intelligence, more imagination, and more humanity.
William Tarpeh
William Tarpeh meets you with an easy warmth. In his Stanford lab he carries himself with a quiet sense of joy, as if the work around him is a puzzle he never tires of turning over. Beakers, tubes, and small electrochemical rigs surround him. The place hums with experiments, yet he seems calm in the middle of it all. There is a spark in his eyes that suggests he still cannot believe the world lets him do this for a living.
He grew up in Virginia and went through Thomas Jefferson High School for Science and Technology, a place packed with restless young engineers. At Stanford he studied chemical engineering and picked up a minor in African studies, drawn to the way science intersects with social realities. He pushed deeper into environmental engineering at Berkeley, where he earned both his master’s and his doctorate. Those years shaped the questions that now define his career. How do you take something society ignores and turn it into a resource. How do you build systems that reclaim value from the streams that disappear behind pipes and treatment plants.
His specialty is wastewater, though he talks about it in a way that makes it feel like a living system. He studies the chemistry of urine and industrial effluents with the precision of an engineer and the curiosity of someone who enjoys figuring things out from first principles. Nitrogen, ammonia, disinfectants, valuable compounds. His lab develops ways to extract them and convert them into usable products. Fertilizer that can support local agriculture. Disinfectants that can be made on site. Tools that could give communities more control over their own resources.
The devices in his lab look deceptively simple. Small reactors. Tailored membranes. Electrochemical cells that shepherd ions along clean paths. Beneath that simplicity sits an enormous amount of thinking. He designs systems that can work in the real world. Not just in ideal lab conditions, but out in the field, where water chemistry shifts, maintenance is unpredictable, and budgets are tight. His team tests these technologies in California and abroad, measuring how they behave under pressure and how they might scale.
Talking with him, you sense the way he balances rigor with optimism. He lights up when describing the moment an extraction method achieves a clean separation or when a pilot system produces its first useful product. His excitement is infectious. You can almost see the chain of possibilities expanding in his mind. He rarely talks about accolades, though he received a MacArthur Fellowship in 2025. That recognition captured something real about his work. It is inventive but firmly rooted in practical needs. It aims to make life better for people who rarely see the benefits of advanced engineering.
Photographing him reveals his mix of calm and curiosity. One moment he leans into the science with total focus. The next he lifts his head and breaks into an amused smile. He gives the impression of someone who honors the complexity of the world but still approaches it with a kind of delight. The lab around him becomes a landscape of small mysteries waiting to be solved.
William Tarpeh is reshaping how we think about waste. He treats it not as an endpoint but as a starting point. Something filled with potential. Standing with him in the soft light of the lab, you feel that sense of possibility settling in. The sense that the systems we take for granted could be rebuilt with more intelligence, more imagination, and more humanity.