Sanitation is a key research area at the Berkeley Water Center. See what research and projects are centered around water, sanitation and toilets. 


Mass gatherings can facilitate infectious disease transmission

In a new study published in the American Journal of Epidemiology, a team of interdisciplinary researchers, includign BWC affiliate Justin Remais, found that even modestly sized community gatherings were associated with increased transmission of diarrheal diseases—a major global killer—in a study region in Esmeraldas, Ecuador.

2019 Bay Area WASH Symposium

UC Berkeley welcomed students, professors and researchers interested in water, sanitation and hygiene (WASH) to campus May 3, 2019 for the Bay Area WASH Symposium.

The Pope and Sanitation

Berkeley water PhD student Chris Hyun looks at what the pope says about sanitation. Why? There are about 1.4 billion people without access to proper sanitation. There are about 1.1 billion Catholics in the world. If every Catholic follows what the pope orders in this encyclical, it would go a long way to fixing our sanitation problems. So, what does he say?

The sanitation and urban agriculture nexus: urine collection and application as fertilizer in São Paulo, Brazil

Separately collected urine is an attractive potential fertilizer because of its high nutrient content, low cost, and inherent linkage of urban wastewater management and peri-urban agriculture. Urine from waterless urinals was applied to corn and lettuce plants to examine the impact of urine application rates and frequency on plant growth and soil parameters. In both corn and lettuce experiments, urine application significantly (p < 0.05) increased growth and leaf production relative to control plants. More frequent applications led to lower soil cation exchange capacities for corn and higher soil nitrogen content for both crops. Based on preliminary implementation calculations, waterless urinals at the University of São Paulo (USP), School of Arts, Sciences, and Humanities campus could lead to over 1,500 m3 of water saved and 360 m3 of urine produced on an annual basis. These experiments and modeling results are discussed in the context of scaling up urban urine collection, transport, and fertilization in São Paulo, Brazil.

Solar Drinking Water Disinfection (SODIS) to Reduce Childhood Diarrhoea in Rural Bolivia: A Cluster-Randomized, Controlled Trial

Despite an extensive SODIS promotion campaign we found only moderate compliance with the intervention and no strong evidence for a substantive reduction in diarrhoea among children. These results suggest that there is a need for better evidence of how the well-established laboratory efficacy of this home-based water treatment method translates into field effectiveness under various cultural settings and intervention intensities. Further global promotion of SODIS for general use should be undertaken with care until such evidence is available.

Toilet Cleaners of Lucknow

BWC Co-Director Isha Ray and PhD student CS Sharada Prasad  focus on the back-end of the sanitation chain, on those who clean out latrines where there is no flush or sewer to carry away the waste in a pictoral essay.

Public Spaces, Private Acts: Toilets and Gender Equality

Isha Ray examines gender equality through the lens of access to basic sanitation: If we are to make sanitation truly accessible, we must explicitly design and construct infrastructure that meets the needs of the most marginalized—including the low-income woman whose dignity and mobility rests on the presence of clean, safe facilities outside of the home.

What is Sanitation?

What is Sanitation?

Photos and videos - Rachel Sklar and Sharada Prasad CS, UC Berkeley

Financial Support: The production of this video is partially funded by Partnerships for Enhanced Engagement in Research (PEER) grant supported by USAID and administered by US NAS

How Your Pee Could Help Billions Of People

Most of us flush our urine down the toilet, but William Tarpeh uses it to create fertilizer and hopes to help people in need. See how here.

blueEnergy’s Water and Sanitation Technology for Nicaragua
The enormity of the world’s water and sanitation problems cannot be overstated. UN Water estimates that more than 3 million people die from water, sanitation, and hygiene-related causes each year, and nearly 10 percent of the global disease burden could be reduced through improved water supply, sanitation, hygiene, and water resource management.
Going “Beyond the Bowl” to Achieve Gender Equity in Sanitation

In 2013 Isha Ray, a UC Berkeley professor and international water expert, received a request from UN Women—to determine whether progress on sanitation in the world’s poorest places has been gender equal.

Going Beyond the Bowl to Achieve Gender Equity in Sanitation

This discussion paper by Zachary Burt, Kara Nelson and Isha Ray reviews the extensive literature on sanitation to show that inadequate access to this basic service prevents the realization of a range of human rights and of gender equality. We recognize that “dignity” is a highly culture- and gender-specific term; we therefore argue that sanitation for all—sanitation that serves all genders equally—must be designed and planned explicitly for the unique needs of women and girls.

BWC Leaders Affecting Water Sanitation

Berkeley Water Center Co-Director David Sedlak and Professor Kara Nelson are both affecting the future of direct potable reuse and  just served on an expert panel to advise on developing uniform recycling criteria for indirect potable reuse via surface water augmentation and on the feasibility of developing such criteria for direct potable reuse.

Solving Real People's Real Problems

Cooke Scholar William Tarpeh's work could have a transformational effect on the developing world.  A doctoral student in environmental engineering at UC Berkeley, William is reimagining sanitation and developing ways to convert waste into a precious resource, fertilizer.  Will said, "I think that a lot of the solutions to our world’s most pressing problems are in the minds of children who are simply preoccupied with survival. Sanitation for me is one way to remove that preoccupation with just surviving. These kids are instead thinking about how to change their own futures and the future of our world."

The Sustainability and Impact of Water, Sanitation, and Hygiene Interventions in India

Diarrheal diseases kill approximately 1.5 million children under age five annually, representing the second leading cause of death and the leading cause of malnutrition for this age group.1  Reducing the prevalence of diarrhea in developing countries requires expanding access to improved water and sanitation facilities and improving hygienic practices that contaminate water. This study evaluated a range of health and non-health benefits of a comprehensive program to expand and improve water and sanitation infrastructure and improve hygienic practices in the Southern Indian state of Tamil Nadu.

In-toilet disinfection of fresh fecal sludge with ammonia naturally present in excreta

The goal of Professor Kara Nelson's project was to develop a method for disinfecting fresh excreta within the toilet itself, thereby reducing the risk of pathogen exposure associated with removal and  disposal or end-use of the fecal sludge. We aimed to develop a process that could be incorporated into self-contained waterless toilets (the waste is stored in containers rather than a pit) that are emptied regularly by a service provider. 

Potty mouth: Would you drink recycled toilet water to save the world? (Psst, you may already be doing so)

As the water crisis deepens, cities are recycling the H2O we flush away and reclaiming it as drinking water. BWC Co-Director David Sedlak comments.


ERG student Emily Woods created her own start-up company, Sanivation, to focus on solar treatment of human waste and conversion to charcoal in Kenya. Sanivation is a social enterprise dedicated to improving the overall dignity, health, and environment of urbanizing communities in East Africa through delivering clean, safe, and efficient sanitation services.

Celebrating World Toilet Day, reinventing sanitation

In the lab, BWC doctoral student William Tarpeh is using new technical processes to extract nitrogen from urine to create a nutrient-rich fertilizer. “From a technical perspective,” he says, “urine has a lot of interesting chemistry going on.”

Isha Ray: Gender Equality and Sanitation at TedXBerkeley

All too often, we think of gender equality in terms of associated “hot button” words—education, pay, civil rights. But we neglect an essential part of the female experience—dignity in access to toilets—which has profound implications for achieving gender equality. Isha Ray, Co-Director of the Berkeley Water Center, shares the experiences of women worldwide and why we need to reevaluate our understanding of women’s issues.

The Human Right(s) to Water and Sanitation: History, Meaning, and the Controversy OverPrivatization

The recognition by the United Nations (U.N.) General Assembly1 and the U.N. Human Rights Council2 in 2010 of a human right to safe drinking water and sanitation has propelled awareness of the global water and sanitation crisis to new heights, while also raising a host of challenging issues. This article surveys the evolution of this right by attempting to place it within a broader historical context and by addressing some of the controversies around privatization.

The effect of India’s total sanitation campaign on defecation behaviors and child health in rural Madhya Pradesh: a cluster randomized controlled trial

Poor sanitation is thought to be a major cause of enteric infections among young children. However, there are no previously published randomized trials to measure the health impacts of large-scale sanitation programs.