Kara L. Nelson

Current PhD Students

Karina Chavarria  


Karina’s research focuses on microbial ecosystems at the interface of drinking water infrastructure and environmental health in low- and middle-income countries. She focuses on the effects of intermittent water supply on bacterial diversity of drinking water to improve our understanding of water quality. Her broader research interests include waterborne pathogens, sustainable drinking water and sanitation, and wastewater reuse.

John Erickson  


John researches piped drinking water systems that operate intermittently and the effect of intermittent supply on water quality and infrastructure condition. The research is intended to help water utilities prioritize infrastructure investments and operate their distribution systems more effectively.

Erica Fuhrmeister  


Erica’s research focuses on water and sanitation in low and middle income countries. She is currently working on a sanitation impact study in rural Bangladesh to assess if access to improved sanitation facilities reduces fecal contamination in the household environment. Her broader research interests include environmental microbiology, pathogen transmission and wastewater infrastructure.

Lauren Kennedy


Lauren is interested in the impact of disinfectants on microbial communities in drinking water distribution systems and in potable reuse systems.

Will Tarpeh


Will focuses on nitrogen recovery as ammonia from source-separated urine in source-separated and combined waste streams. He focuses on two physicochemical processes: ion exchange and electrochemistry. Applications for these techniques range from treating side streams at wastewater treatment plants to decentralized treatment systems. His other research interests include sustainable sanitation and scaling, evaluating, and implementing technologies in resource-constrained communities. 

Anne Thebo


Anne Thebo is a PhD student in environmental engineering whose research focuses on understanding the impacts of wastewater irrigation in developing countries. She is conducting a spatially based assessment of wastewater irrigation at the global scale and a case study in Hubli-Dharwad, India evaluating the relationship between irrigation practices, health, and upstream sanitation infrastructure. Her work seeks to both quantify the extent of irrigation with untreated wastewater and better understand the factors which either exacerbate or mitigate risks associated with this practice.

Ileana Wald


Ileana is currently working on a project that investigates resource recovery from urine in source-separated waste streams. Her broader research interests include decentralized waste treatment, sustainable sanitation technologies and pathogen removal from waste treatment systems.

Current Postdoctoral Researchers

Andrea Silverman


Andrea's research interests include waterborne pathogens, natural mechanisms of disinfection, wastewater reuse, and low-cost wastewater/fecal sludge treatment to mitigate the microbial health risks associated with waste reuse. Andrea studies sunlight disinfection of viruses in the laboratory and, in the field, its application as a low-cost intervention to treat wastewater used in urban, irrigated agriculture in Ghana. 



Current Undergraduate Researchers


Former Lab Members


Andrew Torkelson, PhD 2015


Andy is currently a consultant at Geosyntec.

Mi Nguyen, PhD 2015 


Mi is currently a postdoctoral research at Eawag in Dubendorf, Switzerland.  

Fermin Reygadas, PhD 2014 


Fermin is currently the Director of Fundacion Cantaro Azul a non-profit organization he co-founded that designs and implements safe water, hygiene, and sanitation programs in underserved communities.


Rabia Chaudhry, PhD 2014.


Rabia is currently a AAAS Science and Technology Fellow in Washington, D.C.

Jannis Wenk, Postdoc 2012-2014  


Jannis is currently a Lecturer in Chemical Engineering at the University of Bath, U.K.


Emily Kumpel, Ph.D. 2013


Emily Kumpel is postdoctoral researcher at The Aquaya Institute in Nairobi, Kenya.

Temitope Ogunyoku, Postdoc 2011-2013.


Temitope Ogunyoku is currently at IBM Research-Africa in Nairobi, Kenya.



Postdoctoral researchers (current position): Jee Yeon Kim (2009-2010; Samsung Research Group); David Love (2007-2009; Johns Hopkins University); Allegra da Silva (2008-2009; CDM); Maria Raynal (2007-2008 ; Universidad National Autonoma de México); Tamar Kohn (2004-2006; école Polytéchnique Fédérale de Lausanne); Jose Antonio Barrios (2005; National Water Commission, México)

Ph.D. students: Sintana Vergara (May 2012; World Bank); Michael Fisher (July 2011; Microvi Technologies); Khalid Kadir (July 2010; lecturer, U.C. Berkeley); Ashley Murray (May 2009; Founder, Waste Enterprisers, Accra, Ghana); Gordon Williams (May 2009; Trussell Technologies); Sarah Silkie (August 2008); Brian Pecson (Fall 2006; Trussell Technologies); Tryg Lundquist (Fall 2006; Associate Professor, Cal State San Luis Obispo)

M.S. students: Deepak Subramanian, Alejandro Guido, Jeff Dahm, Forest Kaser, Micah Lang, Fermin Reygadas, Sarah Brownell, Hans Schwing, Amy Pickering, Alicia Chakrabati, IlJoo Yang, Matthew Tolcher 

B.S. students: Fikreselam Habebo, Katya Cherukumilli, Malavika Neti, Douglas Fabini, Joshua Song, Majid Khan, Brian Coox, Ofelia Romero, Rachel Peletz, April Wong, Sonia Lopez, Ali Kattan, Senem Surelli