Bio

Jennifer (“Jenna”) Davis is an Associate Professor in the Department of Civil and Environmental Engineering and the Higgins-Magid Senior Fellow at the Woods Institute for the Environment, both of Stanford University. Professor Davis’ research and teaching is focused at the interface of engineered water supply and sanitation systems and their users in developing countries. With a background in public health, infrastructure planning, and environmental science & engineering, Davis explores questions related to interventions that trigger household investment in water, sanitation, and hygiene improvements; the features of water and sanitation services that users value and why; and the health and economic impacts of improvements in water supply and sanitation. She has conducted field research in more than a dozen countries, including most recently Kenya, Mozambique, and Bangladesh. Over the past five years, approximately 25 graduate students and post-docs have obtained training in the field with Davis's projects.

Academic Appointments

Professional Education

  • PhD, UNC-Chapel Hill (1998)
  • MSPH, UNC-Chapel Hill (1995)

Contact

Links

Current Research and Scholarly Interests

Professor Davis’ research and teaching is focused at the interface of engineered water supply and sanitation systems and their users in developing countries. With a background in public health, infrastructure planning, and environmental science & engineering, Davis explores questions related to interventions that trigger household investment in water, sanitation, and hygiene improvements; the features of water and sanitation services that users value and why; and the health and economic impacts of improvements in water supply and sanitation. She has conducted field research in more than a dozen countries, including most recently Kenya, Mozambique, and Bangladesh.

Projects

  • Chlorine Disinfection Systems For Low Income Urban Areas: Bangladesh, Stanford University

    Little work has been done to explore intermediate options between promoting household point-of-use (POU) water treatment technologies (treating drinking water in the home) and expensive city-wide networked water treatment (piped water to individual households). The project addresses this technology gap by developing and evaluating low-cost, in-line chlorination systems that can reduce contamination of drinking water in low-income areas of Dhaka, Bangladesh. This project is in collaboration with Dr. Steve Luby at the International Center for Diarrheal Diseases Research, Bangladesh (ICDDR'B) in Dhaka.

    Current definitions of “access to improved water supply” are based on a technological standard, one that does not take into account the microbiological quality of water accessed by households. Thus, whereas some 800 million people are considered to be lacking access to “improved” water supplies, the number who lack access to safe water is likely to be much higher. The field of POU water treatment has emerged from the understanding that centralized water supply is prohibitively expensive for low-income country governments to build in the near future. At the same time, following several decades of implementation, evidence suggests that uptake and consistent use of POU products among households is limited. This project seeks to explore low-cost chlorinatin systems as an alternative.

    Location

    Bangladesh, Dhaka

  • Rural Health and Development At the Food Water Nexus: Kenya, Civil Environmental Enginering Dept., Stanford University

    This project will explore water-nutrition-health interconnections and will serve as a stepping stone toward the development of theoretical and experimental paradigms linking water, agriculture, and health. The broad goals of the project are 1) to investigate the interactions between household productive and domestic water use, nutritional outcomes, and infectious disease, and 2) to identify local interventions and policy responses that are likely to improve overall health outcomes. More specifically, the project will identify the extent which, and potential causal mechanisms by which, access to domestic and productive water supplies and associated nutritional benefits affect the progression of both HIV and TB among adults living in rural African households.

    Location

    Kenya

2015-16 Courses

Stanford Advisees

All Publications

  • Hands and Water as Vectors of Diarrhea! Pathogens in Bagannoyo, Tanzania ENVIRONMENTAL SCIENCE & TECHNOLOGY Mattioli, M. C., Pickering, A. J., Gilsdorf, R. J., Davis, J., Boehm, A. B. 2013; 47 (1): 355-363

    Abstract

    Diarrheal disease is a leading cause of under-five childhood mortality worldwide, with at least half of these deaths occurring in sub-Saharan Africa. Transmission of diarrheal pathogens occurs through several exposure routes including drinking water and hands, but the relative importance of each route is not well understood. Using molecular methods, this study examines the relative importance of different exposure routes by measuring enteric bacteria (pathogenic Escherichia coli) and viruses (rotavirus, enterovirus, adenovirus) in hand rinses, stored water, and source waters in Bagamoyo, Tanzania. Viruses were most frequently found on hands, suggesting that hands are important vectors for viral illness. The occurrence of E. coli virulence genes (ECVG) was equivalent across all sample types, indicating that both water and hands are important for bacterial pathogen transmission. Fecal indicator bacteria and turbidity were good predictors of ECVG, whereas turbidity and human-specific Bacteroidales were good predictors of viruses. ECVG were more likely found in unimproved water sources, but both ECVG and viral genes were detected in improved water sources. ECVG were more likely found in stored water of households with unimproved sanitation facilities. The results provide insights into the distribution of pathogens in Tanzanian households and offer evidence that hand-washing and improved water management practices could alleviate viral and bacterial diarrhea.

    View details for DOI 10.1021/es303878d

    View details for Web of Science ID 000313220300046

  • Mechanisms of post-supply contamination of drinking water in Bagamoyo Tanzania. Journal of Water & Health Harris, A., R., Davis, J., Boehm, A., B. 2013; 3 (11): 543-54

    View details for DOI 10.2166/wh.2013.023

  • Enteric pathogens in stored drinking water and on caregiver's hands in Tanzanian households with and without reported cases of child diarrhea PLOS One Mattioli, M., Boehm, A., B., Davis, J., Harris, A., Mrisho, M., Pickering, A., J. 2013; 1 (9): e84939

    View details for DOI 10.1371/journal.pone.0084939

  • Does sense of ownership matter for rural water system sustainability? Evidence from Kenya Journal of Water, Sanitation, and Hygiene for Development Marks, S., Onda, K., Davis, J. 2013; 2 (3): 122–133

    View details for DOI 10.2166/washdev.2013.098

  • Socioeconomic and environmental impacts of domestic bio-digesters: Evidence from Arusha, Tanzania Energy for Sustainable Development Laramee, J., Davis, J. 2013

    View details for DOI 10.1016/j.esd.2013.02.001

  • Does User Participation Lead to Sense of Ownership for Rural Water Systems? Evidence from Kenya WORLD DEVELOPMENT Marks, S. J., Davis, J. 2012; 40 (8): 1569-1576

    View details for DOI 10.1016/j.worlddev.2012.03.011

    View details for Web of Science ID 000306028400007

  • Fecal Contamination and Diarrheal Pathogens on Surfaces and in Soils among Tanzanian Households with and without Improved Sanitation ENVIRONMENTAL SCIENCE & TECHNOLOGY Pickering, A. J., Julian, T. R., Marks, S. J., Mattioli, M. C., Boehm, A. B., Schwab, K. J., Davis, J. 2012; 46 (11): 5736-5743

    Abstract

    Little is known about the extent or pattern of environmental fecal contamination among households using low-cost, on-site sanitation facilities, or what role environmental contamination plays in the transmission of diarrheal disease. A microbial survey of fecal contamination and selected diarrheal pathogens in soil (n = 200), surface (n = 120), and produce samples (n = 24) was conducted in peri-urban Bagamoyo, Tanzania, among 20 households using private pit latrines. All samples were analyzed for E. coli and enterococci. A subset was analyzed for enterovirus, rotavirus, norovirus GI, norovirus GII, diarrheagenic E. coli, and general and human-specific Bacteroidales fecal markers using molecular methods. Soil collected from the house floor had significantly higher concentrations of E. coli and enterococci than soil collected from the latrine floor. There was no significant difference in fecal indicator bacteria levels between households using pit latrines with a concrete slab (improved sanitation) versus those without a slab. These findings imply that the presence of a concrete slab does not affect the level of fecal contamination in the household environment in this setting. Human Bacteroidales, pathogenic E. coli, enterovirus, and rotavirus genes were detected in soil samples, suggesting that soil should be given more attention as a transmission pathway of diarrheal illness in low-income countries.

    View details for DOI 10.1021/es300022c

    View details for Web of Science ID 000304783000017

    View details for PubMedID 22545817

  • Freshwater Availability and Water Fetching Distance Affect Child Health in Sub-Saharan Africa ENVIRONMENTAL SCIENCE & TECHNOLOGY Pickering, A. J., Davis, J. 2012; 46 (4): 2391-2397

    Abstract

    Currently, more than two-thirds of the population in Africa must leave their home to fetch water for drinking and domestic use. The time burden of water fetching has been suggested to influence the volume of water collected by households as well as time spent on income generating activities and child care. However, little is known about the potential health benefits of reducing water fetching distances. Data from almost 200,?000 Demographic and Health Surveys carried out in 26 countries were used to assess the relationship between household walk time to water source and child health outcomes. To estimate the causal effect of decreased water fetching time on health, geographic variation in freshwater availability was employed as an instrumental variable for one-way walk time to water source in a two-stage regression model. Time spent walking to a household's main water source was found to be a significant determinant of under-five child health. A 15-min decrease in one-way walk time to water source is associated with a 41% average relative reduction in diarrhea prevalence, improved anthropometric indicators of child nutritional status, and a 11% relative reduction in under-five child mortality. These results suggest that reducing the time cost of fetching water should be a priority for water infrastructure investments in Africa.

    View details for DOI 10.1021/es203177v

    View details for Web of Science ID 000300465900056

    View details for PubMedID 22242546

  • Freshwater availability affects child health in sub-Saharan Africa Environmental Science & Technology Pickering, A., Davis, J. 2012

    View details for DOI 10.1021/es203177v

  • The role of productive water use in women's livelihoods: Evidence from rural Senegal Water Alternatives Houweling, E., van, Hall, R., Diop, A., S., Davis, J., Seiss, M. 2012; 3 (5): 658-677
  • Water supply services for Africa's urban poor: the role of resale JOURNAL OF WATER AND HEALTH Zuin, V., Ortolano, L., Alvarinho, M., Russel, K., Thebo, A., Muximpua, O., Davis, J. 2011; 9 (4): 773-784

    Abstract

    In sub-Saharan Africa only 35% of the urban population has access to a piped water connection on their premises. The majority of households obtain water from public standpipes or from neighbors who are connected to the municipal network. Water resale is often prohibited, however, because of concerns about affordability and risks to public health. Using data collected from 1,377 households in Maputo, Mozambique, we compare the microbiological quality, as well as the time and money costs of water supply from individual house connections, public standpipes, and water obtained from neighbors. Households with their own water connections have better service across virtually all indicators measured, and express greater satisfaction with their service, as compared with those using other water sources. Households purchasing water from their neighbors pay lower time and money costs per liter of water, on average, as compared with those using standpipes. Resale competes favorably with standpipes along a number of service quality dimensions; however, after controlling for water supply characteristics, households purchasing water from neighbors are significantly less likely to be satisfied with their water service as compared with those using standpipes.

    View details for DOI 10.2166/wh.2011.031

    View details for Web of Science ID 000297599300016

    View details for PubMedID 22048436

  • Increasing the Role of Economics in Environmental Research (or Moving beyond the Mindset That Economics = Accounting) ENVIRONMENTAL SCIENCE & TECHNOLOGY Characklis, G. W., Adriaens, P., Braden, J. B., Davis, J., Hamilton, B., Hughes, J. B., Small, M. J., Wolfe, J. 2011; 45 (15): 6235-6236

    View details for DOI 10.1021/es202128s

    View details for Web of Science ID 000293196400007

    View details for PubMedID 21740005

  • Drivers of Conflict in Developing Country Infrastructure Projects: Experience from the Water and Pipeline Sectors JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT-ASCE Boudet, H. S., Jayasundera, D. C., Davis, J. 2011; 137 (7): 498-511

    View details for DOI 10.1061/(ASCE)CO.1943-7862.0000333

    View details for Web of Science ID 000292516700004

  • The Effects of Informational Interventions on Household Water Management, Hygiene Behaviors, Stored Drinking Water Quality, and Hand Contamination in Peri-Urban Tanzania AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE Davis, J., Pickering, A. J., Rogers, K., Mamuya, S., Boehm, A. B. 2011; 84 (2): 184-191

    Abstract

    Safe water storage and hand hygiene have been shown to reduce fecal contamination and improve health in experimental settings; however, triggering and sustaining such behaviors is challenging. This study investigates the extent to which personalized information about Escherichia coli contamination of stored water and hands influenced knowledge, reported behaviors, and subsequent contamination levels among 334 households with less than 5-year-old children in peri-urban Dar es Salaam, Tanzania. One-quarter of the study participants received information about strategies to reduce risk of water- and sanitation-related illness. Respondents in another three study cohorts received this same information, along with their household's water and/or hand-rinse test results. Findings from this study suggest that additional work is needed to elucidate the conditions under which such testing represents a cost-effective strategy to motivate improved household water management and hand hygiene.

    View details for DOI 10.4269/ajtmh.2011.10-0126

    View details for Web of Science ID 000287003900002

    View details for PubMedID 21292883

  • Efficacy of alcohol-based hand sanitizer on hands soiled with dirt and cooking oil JOURNAL OF WATER AND HEALTH Pickering, A. J., Davis, J., Boehm, A. B. 2011; 9 (3): 429-433

    Abstract

    Handwashing education and promotion are well established as effective strategies to reduce diarrhea and respiratory illness in countries around the world. However, access to reliable water supplies has been identified as an important barrier to regular handwashing in low-income countries. Alcohol-based hand sanitizer (ABHS) is an effective hand hygiene method that does not require water, but its use is not currently recommended when hands are visibly soiled. This study evaluated the efficacy of ABHS on volunteers' hands artificially contaminated with Escherichia coli in the presence of dirt (soil from Tanzania) and cooking oil. ABHS reduced levels of E. coli by a mean of 2.33 log colony forming units (CFU) per clean hand, 2.32 log CFU per dirt-covered hand, and 2.13 log CFU per oil-coated hand. No significant difference in efficacy was detected between hands that were clean versus dirty or oily. ABHS may be an appropriate hand hygiene method for hands that are moderately soiled, and an attractive option for field settings in which access to water and soap is limited.

    View details for DOI 10.2166/wh.2011.138

    View details for Web of Science ID 000293624300001

    View details for PubMedID 21976190

  • Site fights Global Projects McAdam, D., Schaffer Boudet, H., Davis, J., Orr, Ryan, J., Scott, W., Richard, Levitt, Raymond, E. edited by Scott, W. R., Levitt, R. E., Orr, R. J. Cambridge, UK: Cambridge University Press. 2011
  • Water resale to neighbors in Maputo, Mozambique: costs, service quality, and user satisfaction Journal of Water and Health Zuin, V., Ortolano, L., Alvarinho, M., Russel, K., Thebo, A., Muximpua, O., Davis, J. 2011; 9 (4): 773-784

    View details for DOI 10.2166/wh.2011.031

  • Drivers of conflict in global infrastructure projects: Experience from the water and pipeline sectors Journal of Construction Engineering and Managemen Schaffer-Boude, H., Jayasundera, D., C., Davis, J. 2011; 7 (137): 498-511

    View details for DOI 10.1061/(ASCE)CO.1943-7862.0000333

  • Understanding Household Behavioral Risk Factors for Diarrheal Disease in Dar es Salaam: A Photovoice Community Assessment Journal of Environmental and Public Health Badowski, N., Castro, C., Montgomery, M., Pickering, A., Mamuya, S., Davis, J. 2011

    View details for DOI 10.1155/2011/130467

  • "Site Fights": Explaining Opposition to Pipeline Projects in the Developing World1 SOCIOLOGICAL FORUM McAdam, D., Boudet, H. S., Davis, J., Orr, R. J., Scott, W. R., Levitt, R. E. 2010; 25 (3): 401-427

    View details for DOI 10.1111/j.1573-7861.2010.01189.x

    View details for Web of Science ID 000280638000001

  • Hands, Water, and Health: Fecal Contamination in Tanzanian Communities with Improved, Non-Networked Water Supplies ENVIRONMENTAL SCIENCE & TECHNOLOGY Pickering, A. J., Davis, J., Walters, S. P., Horak, H. M., Keymer, D. P., Mushi, D., Strickfaden, B., Chynoweth, J. S., Liu, J., Blum, A., Rogers, K., Boehm, A. B. 2010; 44 (9): 3267-3272

    Abstract

    Almost half of the world's population relies on non-networked water supply services, which necessitates in-home water storage. It has been suggested that dirty hands play a role in microbial contamination of drinking water during collection, transport, and storage. However, little work has been done to evaluate quantitatively the association between hand contamination and stored water quality within households. This study measured levels of E. coli, fecal streptococci, and occurrence of the general Bacteroidales fecal DNA marker in source water, in stored water, and on hands in 334 households among communities in Dar es Salaam, Tanzania, where residents use non-networked water sources. Levels of fecal contamination on hands of mothers and children were positively correlated to fecal contamination in stored drinking water within households. Household characteristics associated with hand contamination included mother's educational attainment, use of an improved toilet, an infant in the household, and dissatisfaction with the quantity of water available for hygiene. In addition, fecal contamination on hands was associated with the prevalence of gastrointestinal and respiratory symptoms within a household. The results suggest that reducing fecal contamination on hands should be investigated as a strategy for improving stored drinking water quality and health among households using non-networked water supplies.

    View details for DOI 10.1021/es903524m

    View details for Web of Science ID 000277067000014

    View details for PubMedID 20222746

  • Efficacy of Waterless Hand Hygiene Compared with Handwashing with Soap: A Field Study in Dar es Salaam, Tanzania AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE Pickering, A. J., Boehm, A. B., Mwanjali, M., Davis, J. 2010; 82 (2): 270-278

    Abstract

    Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed.

    View details for DOI 10.4269/ajtmh.2010.09-0220

    View details for Web of Science ID 000274263300018

    View details for PubMedID 20134005

  • Microbial and metal water quality in rain catchments compared with traditional drinking water sources in the East Sepik Province, Papua New Guinea JOURNAL OF WATER AND HEALTH Horak, H. M., Chynoweth, J. S., Myers, W. P., Davis, J., Fendorf, S., Boehm, A. B. 2010; 8 (1): 126-138

    Abstract

    In Papua New Guinea, a significant portion of morbidity and mortality is attributed to water-borne diseases. To reduce incidence of disease, communities and non-governmental organizations have installed rain catchments to provide drinking water of improved quality. However, little work has been done to determine whether these rain catchments provide drinking water of better quality than traditional drinking water sources, and if morbidity is decreased in villages with rain catchments. The specific aim of this study was to evaluate the quality of water produced by rain catchments in comparison with traditional drinking water sources in rural villages in the East Sepik Province. Fifty-four water sources in 22 villages were evaluated for enterococci and Escherichia coli densities as well as 14 health-relevant metals. In addition, we examined how the prevalence of diarrhoeal illness in villages relates to the type of primary drinking water source. The majority of tested metals were below World Health Organization safety limits. Catchment water sources had lower enterococci and E. coli than other water sources. Individuals in villages using Sepik River water as their primary water source had significantly higher incidence of diarrhoea than those primarily using other water sources (streams, dug wells and catchments).

    View details for Web of Science ID 000275310700014

    View details for PubMedID 20009255

  • Water quality of water in rain catchments compared to other drinking water sources in the East Sepik Province, Papua New Guinea Journal of Water and Health Horak, H., M., Chynoweth, J., S., Myers, W., P., Davis, J., A., Fendorf, S., Boehm, A., B. 2010; 8: 126-138
  • Bacterial hand contamination among Tanzanian mothers varies temporally and following household activities Tropical Medicine & International Health Pickering, A., Julian, T., Boehm, A., Davis, J. 2010

    View details for DOI 10.1111/j.1365-3156.2010.02677.x

  • How well is the demand-driven, community management model for rural water supply systems doing? Evidence from Bolivia, Peru and Ghana WATER POLICY Whittington, D., Davis, J., Prokopy, L., Komives, K., Thorsten, R., Lukacs, H., Bakalian, A., Wakeman, W. 2009; 11 (6): 696-718

    View details for DOI 10.2166/wp.2009.310

    View details for Web of Science ID 000272199200004

  • Sustaining the benefits of rural water supply investments: Experience from Bolivia Post-construction Support and Sustainability in Community-Managed Rural Water Supply: Case Studies in Peru, Bolivia, and Ghana Davis, J., Luckas, H., Jeuland, M., Soto, B., Lizarraga, G., Alvestegui, A. edited by Bakalian, A., Wakeman, W. Washington, DC: The World Bank. 2009
  • The economic returns to water and sanitation investments Global Crises, Global Solutions: Costs and Benefits Davis, J. edited by Lomberg, B. Cambridge, UK: Cambridge University Press. 2009
  • Explaining variation in opposition to pipeline projects in the developing world Environmental Politics McAdam, D., Schafer, H., Davis, J., Orr, R. 2009; 2 (18): 307-308
  • Sustaining the benefits of rural water supply investments: Experience from Cochabamba and Chuquisaca, Bolivia WATER RESOURCES RESEARCH Davis, J., Lukacs, H., Jeuland, M., Alvestegui, A., Soto, B., Lizarraga, G., Bakalian, A., Wakeman, W. 2008; 44 (12)

    View details for DOI 10.1029/2007WR006550

    View details for Web of Science ID 000261889600001

  • Improving access to water supply and sanitation in urban India: microfinance for water and sanitation infrastructure development WATER SCIENCE AND TECHNOLOGY Davis, J., White, G., Damodaron, S., Thorsten, R. 2008; 58 (4): 887-891

    Abstract

    This article summarises initial findings of a study to explore the potential of providing micro-financing for low-income households wishing to invest in improved water supply and sanitation services. Through in-depth interviews with more than 800 households in the city of Hyderabad in India, we conclude that, even if provided with market (not concessional) rates of financing, a substantial proportion of poor households would invest in water and sewer network connections.

    View details for DOI 10.2166/wst.2008.671

    View details for Web of Science ID 000259176600019

    View details for PubMedID 18776626

  • Sustaining the benefits of rural water supply investments: Experience from Bolivia Water Resources Research Davis, J., Luckas, H., Jeuland, M., Soto, B., Lizarraga, G. 2008; 44: W12427

    View details for DOI 10.1029/2007WR006550

  • Private-sector Participation in the Water and Sanitation Sector Annual Review of Environment and Resources Davis, J. 2005; 30: 1-39
  • Challenges for Water Sector Reform in Transition Economies Water Policy Davis, J., Whittington, D. 2004; 4 (6): 1-15
  • Corruption in Public Services: Experience from South Asia’s Water and Sanitation Sector World Development Davis, J. 2003; 1 (32): 53-71
  • Scaling Up Slum Upgrading Efforts: Where are the Bottlenecks? International Development Planning Review Davis, J. 2003; 3 (26): 301-319
  • Assessing Community Preferences for Development Initiatives: Are Willingness-to-pay Studies Robust to Mode Effects? World Development Davis, J. 2002; 4 (32): 655-672
  • Implementing a Demand-driven Approach to Community Water Supply Planning: A Case Study of Lugazi, Uganda Water Resources and Economic Development, Cheltenham Whittington, D., Davis, J., McClelland, E. edited by Saleth, R. M. UK: Edward Elgar Publishing. 2002
  • How Important is Improved Water Infrastructure to Microenterprises? Evidence from Uganda World Development  Davis, J., Kang, A., Vincent, J., Whittington, D. 2001; 10 (29): 1753-1767
  • Designing a “Neighborhood Deal” for Urban Sewers: A Case Study of Semarang, Indonesia Journal of Planning Education and Research Whittington, D., Davis, J., Miarsono, H., Pollard, R. 1999; 3 (19): 297-308
  • Implementing a Demand-driven Approach to Community Water Supply Planning: A Case Study of Lugazi, Uganda Water International Whittington, D., Davis, J., McClelland, E. 1999; 3 (23): 134-145
  • Participatory Research Techniques for Development Projects: A Comparison of the Contingent Valuation and Community Dialogue methods Economic Development and Cultural Change Davis, J., Whittington, D. 1998; 1 (47): 73-81