The global risks of increasing reliance on bottled water

Journal Paper
Alasdair Cohen & Isha Ray
Nature Sustainability, 1: 327 – 329
Publication year: 2018

The rapid growth of bottled water use in low- and middle-income countries, and its normalization as a daily
source of drinking water, does not provide a pathway to universal access. Generous and sustained investment in
centralized and community utilities remains the most viable means for achieving safe water access for all.

Measuring User Compliance and Cost Effectiveness of Safe Drinking Water Programs: A Cluster-Randomized Study of Household Ultraviolet Disinfection in Rural Mexico

Journal Paper
Fermín Reygadas, Joshua S. Gruber, Lindsay Dreizler, Kara L. Nelson & Isha Ray
American Journal of Tropical Medicine and Hygiene
Publication year: 2018

Abstract

Low adoption and compliance levels for household water treatment and safe storage (HWTS) technologies have made it challenging for these systems to achieve measurable health benefits in the developing world. User compliance remains an inconsistently defined and poorly understood feature of HWTS programs. In this article, we develop a comprehensive approach to understanding HWTS compliance. First, our Safe Drinking Water Compliance Framework disaggregates and measures the components of compliance from initial adoption of the HWTS to exclusive consumption of treated water. We apply this framework to an ultraviolet (UV)–based safe water system in a cluster-randomized controlled trial in rural Mexico. Second, we evaluate a no-frills (or “Basic”) variant of the program as well as an improved (or “Enhanced”) variant, to test if subtle changes in the user interface of HWTS programs could improve compliance. Finally, we perform a full-cost analysis of both variants to assess their cost effectiveness (CE) in achieving compliance. We define “compliance” strictly as the habit of consuming safe water. We find that compliance was significantly higher in the groups where the UV program variants were rolled out than in the control groups. The Enhanced variant performed better immediately postintervention than the Basic, but compliance (and thus CE) degraded with time such that no effective difference remained between the two versions of the program.

From intermittent to continuous service: Costs, benefits, equity and sustainability of water system reforms in Hubli-Dharwad, India

Journal Paper
Zachary Burt, Ayşe Ercümen, Narayana Billava & Isha Ray
World Development, 109: 121 – 133
Publication year: 2018

Abstract

Urban service provision falls somewhere on the continuum of lower-cost, lower-quality, unreliable and intermittent to higher-cost, higher-quality, reliable and continuous. Piped water services in India are generally in the former category, but efforts are underway in some cities to shift to continuous supply. We use a matched-cohort research design to evaluate one such effort: an upgrade to continuous water service in a pilot zone of Hubli-Dharwad, India, while the rest of the city remained on intermittent services. We conducted a survey of ∼4000 households with four rounds of data collection over 15 months. We evaluated the household-level net benefits, the equity of their distribution, and the affordability of water access under continuous supply. We also evaluated the project at the system-level (household and utility), estimating the net present value of the upgrade and the feasibility of scale-up to the entire city. We found positive net benefits for households overall, but uneven distribution of these benefits across socio-economic strata. We also found that the costs of supply augmentation, a necessary step for scale-up, significantly reduced the project net present value. The potential for scale-up is thus unclear.

Flows, leaks and blockages in informational interventions: A field experimental study of Bangalore's water sector

Journal Paper
Tanu Kumar, Alison E.Post & Isha Ray
World Development, 106: 149 – 160
Publication year: 2018

Abstract

Many policies and programs based on informational interventions hinge upon the assumption that providing citizens with information can help improve the quality of public services, or help citizens cope with poor services. We present a causal framework that can be used to identify leaks and blockages in the information production and dissemination process in such programs. We conceptualize the “information pipeline” as a series of connected nodes, each of which constitutes a possible point of blockage. We apply the framework to a field-experimental evaluation of a program that provided households in Bangalore, India, with advance notification of intermittently provided piped water. Our study detected no impacts on household wait times for water or on how citizens viewed the state, but found that notifications reduced stress. Our framework reveals that, in our case, noncompliance among human intermediaries and asymmetric gender relations contributed in large part to these null-to-modest results. Diagnostic frameworks like this should be used more extensively in development research to better understand the mechanisms responsible for program success and failure, to identify subgroups that actually received the intended treatment, and to identify potential leaks and blockages when replicating existing programs in new settings.

User preferences and willingness to pay for safe drinking water: Experimental Evidence from Rural Tanzania

Journal Paper
Zachary Burt, Robert M Njee, Yolanda Mbatia, Veritas Msimbe, Joe Brown, Thomas F Clasen, Hamisi M Malebo & Isha Ray
Social Science and Medicine, 173:63 – 71
Publication year: 2017

Abstract

Almost half of all deaths from drinking microbiologically unsafe water occur in Sub-Saharan Africa. Household water treatment and safe storage (HWTS) systems, when consistently used, can provide safer drinking water and improve health. Social marketing to increase adoption and use of HWTS depends both on the prices of and preferences for these systems. This study included 556 households from rural Tanzania across two low-income districts with low-quality water sources. Over 9 months in 2012 and 2013, we experimentally evaluated consumer preferences for six “low-cost” HWTS options, including boiling, through an ordinal ranking protocol. We estimated consumers’ willingness to pay (WTP) for these options, using a modified auction. We allowed respondents to pay for the durable HWTS systems with cash, chickens or mobile money; a significant minority chose chickens as payment. Overall, our participants favored boiling, the ceramic pot filter and, where water was turbid, PuR™ (a combined flocculant-disinfectant). The revealed WTP for all products was far below retail prices, indicating that significant scale-up may need significant subsidies. Our work will inform programs and policies aimed at scaling up HWTS to improve the health of resource-constrained communities that must rely on poor-quality, and sometimes turbid, drinking water sources.

Predictors of Drinking Water Boiling and Bottled Water Consumption in Rural China: A Hierarchical Modeling Approach

Journal Paper
Alasdair Cohen, Qi Zhang, Qing Luo, Yong Tao, John M Colford, Jr. & Isha Ray
Environmental Science and Technology
Publication year: 2017

Abstract

Approximately two billion people drink unsafe water. Boiling is the most commonly used household water treatment (HWT) method globally and in China. HWT can make water safer, but sustained adoption is rare and bottled water consumption is growing. To successfully promote HWT, an understanding of associated socioeconomic factors is critical. We collected survey data and water samples from 450 rural households in Guangxi Province, China. Covariates were grouped into blocks to hierarchically construct modified Poisson models and estimate risk ratios (RR) associated with boiling methods, bottled water, and untreated water. Female-headed households were most likely to boil (RR = 1.36, p < 0.01), and among boilers those using electric kettles rather than pots had higher income proxies (e.g., per capita TV ownership RR = 1.42, p < 0.01). Higher-income households with younger, literate, and male heads were more likely to purchase (frequently contaminated) bottled water, or use electric kettles if they boiled. Our findings show that boiling is not an undifferentiated practice, but one with different methods of varying effectiveness, environmental impact, and adoption across socioeconomic strata. Our results can inform programs to promote safer and more efficient boiling using electric kettles, and suggest that if rural China’s economy continues to grow then bottled water use will increase.

 

Measuring household consumption and waste in unmetered, intermittent piped water systems

Journal Paper
Emily Kumpel, Cleo Woelfle-Erskine, Isha Ray & Kara Nelson
Water Resources Research, 53: 302 – 315
Publication year: 2017

Abstract

Measurements of household water consumption are extremely difficult in intermittent water supply (IWS) regimes in low‐ and middle‐income countries, where water is delivered for short durations, taps are shared, metering is limited, and household storage infrastructure varies widely. Nonetheless, consumption estimates are necessary for utilities to improve water delivery. We estimated household water use in Hubli‐Dharwad, India, with a mixed‐methods approach combining (limited) metered data, storage container inventories, and structured observations. We developed a typology of household water access according to infrastructure conditions based on the presence of an overhead storage tank and a shared tap. For households with overhead tanks, container measurements and metered data produced statistically similar consumption volumes; for households without overhead tanks, stored volumes underestimated consumption because of significant water use directly from the tap during delivery periods. Households that shared taps consumed much less water than those that did not. We used our water use calculations to estimate waste at the household level and in the distribution system. Very few households used 135 L/person/d, the Government of India design standard for urban systems. Most wasted little water even when unmetered, however, unaccounted‐for water in the neighborhood distribution systems was around 50%. Thus, conservation efforts should target loss reduction in the network rather than at households.

Frontline worker compliance with transparency reforms: Barriers posed by family and financial responsibilities

Journal Paper
Christopher Hyun, Alison E. Post & Isha Ray
Governance, 31: 1 - 18
Publication year: 2017

Abstract

Significant development funding flows to informational interventions intended to improve public services. Such “transparency fixes” often depend on the cooperation of frontline workers who produce or disseminate information for citizens. This article examines frontline worker compliance with a transparency intervention in Bangalore’s water sector. Why did compliance vary across neighborhoods, and why did workers exhibit modest rates of compliance overall? Drawing on ethnographic observation and an original data set, this article finds that variation in workers’ family responsibilities and financial circumstances largely explains variation in compliance with the intervention. Furthermore, workers often prioritize long‐standing responsibilities over new tasks seen as add‐ons, leading to modest rates of compliance overall. Perceptions of “core” jobs can be sticky—especially when reaffirmed through interactions with citizens. This article represents one of the first multimethod companions to a field experiment, and illustrates how the analysis of qualitative and observational data can contribute to impact evaluation.

Determinants of the use of alternatives to arsenic-contaminated shallow groundwater: an exploratory study in rural West Bengal, India

Journal Paper
Caroline Delaire, Abhijit Das, Susan Amrose, Ashok Gadgil, Joyashree Roy & Isha Ray
Journal of Water and Health, 15.5: 799 – 812
Publication year: 2017

Abstract

Shallow groundwater containing toxic concentrations of arsenic is the primary source of drinking water for millions of households in rural West Bengal, India. Often, this water also contains unpleasant levels of iron and non-negligible fecal contamination. Alternatives to shallow groundwater are increasingly available, including government-built deep tubewells, water purchased from independent providers, municipal piped water, and household filters. We conducted a survey of 501 households in Murshidabad district in 2014 to explore what influenced the use of available alternatives. Socioeconomic status and the perceived likelihood of gastrointestinal (GI) illness (which was associated with dissatisfaction with iron in groundwater) were the primary determinants of the use of alternatives. Arsenic knowledge was limited. The choice amongst alternatives was influenced by economic, social, and aesthetic factors, but not by health risk perceptions. The use of purchased water was rarely exclusive and was strongly associated with socioeconomic status, suggesting that this form of market-based water provision does not ensure universal access. Demand for purchased water appeared to decrease significantly shortly after free piped water became available at public taps. Our results suggest that arsenic mitigation interventions that also address co-occurring water problems (iron, GI illness) could be more effective than a focus on arsenic alone.

Upgrading a piped water supply from intermittent to continuous delivery and association with waterborne illness: A matched cohort study in urban India

Journal Paper
Ayşe Ercümen, Benjamin F. Arnold, Emily Kumpel, Zachary Burt, Isha Ray, Kara Nelson, & John M. Colford, Jr
PLoS Medicine, 12(10): e1001892.
Publication year: 2015

Abstract

Background

Intermittent delivery of piped water can lead to waterborne illness through contamination in the pipelines or during household storage, use of unsafe water sources during intermittencies, and limited water availability for hygiene. We assessed the association between continuous versus intermittent water supply and waterborne diseases, child mortality, and weight for age in Hubli-Dharwad, India.

Methods and Findings

We conducted a matched cohort study with multivariate matching to identify intermittent and continuous supply areas with comparable characteristics in Hubli-Dharwad. We followed 3,922 households in 16 neighborhoods with children <5 y old, with four longitudinal visits over 15 mo (Nov 2010–Feb 2012) to record caregiver-reported health outcomes (diarrhea, highly credible gastrointestinal illness, bloody diarrhea, typhoid fever, cholera, hepatitis, and deaths of children <2 y old) and, at the final visit, to measure weight for age for children <5 y old. We also collected caregiver-reported data on negative control outcomes (cough/cold and scrapes/bruises) to assess potential bias from residual confounding or differential measurement error.

Continuous supply had no significant overall association with diarrhea (prevalence ratio [PR] = 0.93, 95% confidence interval [CI]: 0.83–1.04, p = 0.19), bloody diarrhea (PR = 0.78, 95% CI: 0.60–1.01, p = 0.06), or weight-for-age z-scores (Δz = 0.01, 95% CI: −0.07–0.09, p = 0.79) in children <5 y old. In prespecified subgroup analyses by socioeconomic status, children <5 y old in lower-income continuous supply households had 37% lower prevalence of bloody diarrhea (PR = 0.63, 95% CI: 0.46–0.87, p-value for interaction = 0.03) than lower-income intermittent supply households; in higher-income households, there was no significant association between continuous versus intermittent supply and child diarrheal illnesses. Continuous supply areas also had 42% fewer households with ≥1 reported case of typhoid fever (cumulative incidence ratio [CIR] = 0.58, 95% CI: 0.41–0.78, p = 0.001) than intermittent supply areas. There was no significant association with hepatitis, cholera, or mortality of children <2 y old; however, our results were indicative of lower mortality of children <2 y old (CIR = 0.51, 95% CI: 0.22–1.07, p = 0.10) in continuous supply areas. The major limitations of our study were the potential for unmeasured confounding given the observational design and measurement bias from differential reporting of health symptoms given the nonblinded treatment. However, there was no significant difference in the prevalence of the negative control outcomes between study groups that would suggest undetected confounding or measurement bias.

Conclusions

Continuous water supply had no significant overall association with diarrheal disease or ponderal growth in children <5 y old in Hubli-Dharwad; this might be due to point-of-use water contamination from continuing household storage and exposure to diarrheagenic pathogens through nonwaterborne routes. Continuous supply was associated with lower prevalence of dysentery in children in low-income households and lower typhoid fever incidence, suggesting that intermittently operated piped water systems are a significant transmission mechanism for Salmonella typhi and dysentery-causing pathogens in this urban population, despite centralized water treatment. Continuous supply was associated with reduced transmission, especially in the poorer higher-risk segments of the population.

Safe Drinking Water for Low-Income Regions

Journal Paper
Susan Amrose, Zachary Burt & Isha Ray
Annual Review of Environment and Resources, 40:9.1 – 9.29
Publication year: 2015

Abstract

Well into the 21st century, safe and affordable drinking water remains an unmet human need. At least 1.8 billion people are potentially exposed to microbial contamination, and close to 140 million people are potentially exposed to unsafe levels of arsenic. Many new technologies, water quality assessments, health impact assessments, cost studies, and user preference studies have emerged in the past 20 years to further the laudable goal of safe drinking water for all. This article reviews (a) the current literature on safe water approaches with respect to their effectiveness in improving water quality and protectiveness in improving human health, (b) new work on the uptake and use of safe water systems among low-income consumers, (c) new research on the cash and labor costs of safe water systems, and (d) research on user preferences and valuations for safe water. Our main recommendation is that safe water from “source to sip” should be seen as a system; this entire system, rather than a discrete intervention, should be the object of analysis for technical, economic, and health assessments.

Microbiological evaluation of household drinking water treatment in rural China shows benefits of electric kettles: A cross-sectional study

Journal Paper
Alasdair Cohen, Yong Tao, Qing Luo, Gemei Zhong, Jeff Romm, John M Colford, Jr. & Isha Ray
PLoS ONE, 10(9): e0138451
Publication year: 2015

Abstract

Background

In rural China ~607 million people drink boiled water, yet little is known about prevailing household water treatment (HWT) methods or their effectiveness. Boiling, the most common HWT method globally, is microbiologically effective, but household air pollution (HAP) from burning solid fuels causes cardiovascular and respiratory disease, and black carbon emissions exacerbate climate change. Boiled water is also easily re-contaminated. Our study was designed to identify the HWT methods used in rural China and to evaluate their effectiveness.

Methods

We used a geographically stratified cross-sectional design in rural Guangxi Province to collect survey data from 450 households in the summer of 2013. Household drinking water samples were collected and assayed for Thermotolerant Coliforms (TTC), and physicochemical analyses were conducted for village drinking water sources. In the winter of 2013–2104, we surveyed 120 additional households and used remote sensors to corroborate self-reported boiling data.

 

Findings

Our HWT prevalence estimates were: 27.1% boiling with electric kettles, 20.3% boiling with pots, 34.4% purchasing bottled water, and 18.2% drinking untreated water (for these analyses we treated bottled water as a HWT method). Households using electric kettles had the lowest concentrations of TTC (73% lower than households drinking untreated water). Multilevel mixed-effects regression analyses showed that electric kettles were associated with the largest Log10TTC reduction (-0.60, p<0.001), followed by bottled water (-0.45, p<0.001) and pots (-0.44, p<0.01). Compared to households drinking untreated water, electric kettle users also had the lowest risk of having TTC detected in their drinking water (risk ratio, RR = 0.49, 0.34–0.70, p<0.001), followed by bottled water users (RR = 0.70, 0.53–0.93, p<0.05) and households boiling with pots (RR = 0.74, 0.54–1.02, p = 0.06).

Conclusion

As far as we are aware, this is the first HWT-focused study in China, and the first to quantify the comparative advantage of boiling with electric kettles over pots. Our results suggest that electric kettles could be used to rapidly expand safe drinking water access and reduce HAP exposure in rural China.

Field efficacy evaluation and post-treatment contamination risk assessment of an ultraviolet disinfection and safe storage system

Journal Paper
Fermin Reygadas, Joshua S. Gruber, Isha Ray & Kara L. Nelson
Water Research, 85: 74 – 84
Publication year: 2015

Abstract

Inconsistent use of household water treatment and safe storage (HWTS) systems reduces their potential health benefits. Ultraviolet (UV) disinfection is more convenient than some existing HWTS systems, but it does not provide post-treatment residual disinfectant, which could leave drinking water vulnerable to recontamination. In this paper, using as-treated analyses, we report on the field efficacy of a UV disinfection system at improving household drinking water quality in rural Mexico. We further assess the risk of post-treatment contamination from the UV system, and develop a process-based model to better understand household risk factors for recontamination. This study was part of a larger cluster-randomized stepped wedge trial, and the results complement previously published population-level results of the intervention on diarrheal prevalence and water quality. Based on the presence of Escherichia coli(proportion of households with ≥1 E. coli/100 mL), we estimated a risk difference of −28.0% (95% confidence interval (CI): −33.9%, −22.1%) when comparing intervention to control households; −38.6% (CI: −48.9%, −28.2%) when comparing post- and pre-intervention results; and −37.1% (CI: −45.2%, −28.9%) when comparing UV disinfected water to alternatives within the household. We found substantial increases in post-treatment E. coli contamination when comparing samples from the UV system effluent (5.0%) to samples taken from the storage container (21.1%) and drinking glasses (26.0%). We found that improved household infrastructure, additional extractions from the storage container, additional time from when the storage container was filled, and increased experience of the UV system operator were associated with reductions in post-treatment contamination. Our results suggest that the UV system is efficacious at improving household water quality when used as intended. Promoting safe storage habits is essential for an effective UV system dissemination. The drinking glass appears to represent a small but significant source of recontamination that is likely to impact all HWTS systems.

The Drinking Water Disparities Framework: On the origins and persistence of inequities in exposure

Journal Paper
Carolina Balazs & Isha Ray
American Journal of Public Health | Framing Health Matters, 104: 603 – 611
Publication year: 2014

Abstract

With this article, we develop the Drinking Water Disparities Framework to explain environmental injustice in the context of drinking water in the United States. The framework builds on the social epidemiology and environmental justice literatures, and is populated with 5 years of field data (2005–2010) from California’s San Joaquin Valley. We trace the mechanisms through which natural, built, and sociopolitical factors work through state, county, community, and household actors to constrain access to safe water and to financial resources for communities. These constraints and regulatory failures produce social disparities in exposure to drinking water contaminants. Water system and household coping capacities lead, at best, to partial protection against exposure. This composite burden explains the origins and persistence of social disparities in exposure to drinking water contaminants.

Storage and non-payment: persistent informalities within the formal water supply of Hubli-Dharwad, India

Journal Paper
Zachary Burt & Isha Ray
Water Alternatives, 7: 106 – 120
Publication year: 2014

Abstract

Urban water systems in Asia and Africa mostly provide intermittent rather than continuous water supplies; such systems compromise water quality and inconvenience the user. Starting in 2008, an upgrade to continuous (24/7) water services was provided for 10% of the twin cities of Hubli-Dharwad, India, through a process of privatisation and formalisation. The goals were to improve water quality, free consumers from collecting and storing water, and reduce non-revenue (i.e. unpaid for) water. Drawing on household surveys (n = 1986) conducted in 2010-2011 in the 24/7 zones, as well as on a range of interviews, we find that, even with ‘formal’ 24/7 water service, most consumers continue the supposedly ‘informal’ practices of in-home storage and water use without payment of bills. We argue that multiple unaccounted-for factors – including a history of distrust between the consumer and the utility, seemingly small infrastructural details, resistance to higher tariffs, and valuing convenience above water quality – have kept these informal practices embedded within the formalised delivery system. Our research contributes to understanding why formalisation may only partially supplant informal practices even when the formal system is functional and reliable.

Challenges and Achievements in Millennium Development Goals for Water and Sanitation for Women and Girls

Other WritingsUN Discussion Paper
Isha Ray
UN Women Expert Group Briefing Paper
Publication year: 2013

A stepped wedge, cluster-randomized trial of a household UV-disinfection and safe storage drinking water intervention in rural Baja California Sur, Mexico

Journal Paper
Joshua S. Gruber, Fermin Reygadas, Ben Arnold, Isha Ray, Kara L. Nelson & John Colford, Jr
American Journal of Tropical Medicine and Hygiene, 89: 238 – 245
Publication year: 2013

Abstract

In collaboration with a local non-profit organization, this study evaluated the expansion of a program that promoted and installed Mesita Azul, an ultraviolet-disinfection system designed to treat household drinking water in rural Mexico. We conducted a 15-month, cluster-randomized stepped wedge trial by randomizing the order in which 24 communities (444 households) received the intervention. We measured primary outcomes (water contamination and diarrhea) during seven household visits. The intervention increased the percentage of households with access to treated and safely stored drinking water (23–62%), and reduced the percentage of households with  contaminated drinking water (risk difference (RD): −19% [95% CI: −27%, −14%]). No significant reduction in diarrhea was observed (RD: −0.1% [95% CI: −1.1%, 0.9%]). We conclude that household water quality improvements measured in this study justify future promotion of the Mesita Azul, and that future studies to measure its health impact would be valuable if conducted in populations with higher diarrhea prevalence.

Environmental justice implications of arsenic contamination in California’s San Joaquin Valley: a cross-sectional cluster-design examining exposure and compliance in community drinking water systems

Journal Paper
Carolina Balazs, Rachel Morello-Frosch, Alan Hubbard & Isha Ray
Environmental Health, 11:84 (14 November 2012)
Publication year: 2012

Abstract

Background

Few studies of environmental justice examine inequities in drinking water contamination. Those studies that have done so usually analyze either disparities in exposure/harm or inequitable implementation of environmental policies. The US EPA’s 2001 Revised Arsenic Rule, which tightened the drinking water standard for arsenic from 50 μg/L to 10 μg/L, offers an opportunity to analyze both aspects of environmental justice.

Methods

We hypothesized that Community Water Systems (CWSs) serving a higher proportion of minority residents or residents of lower socioeconomic status (SES) have higher drinking water arsenic levels and higher odds of non-compliance with the revised standard. Using water quality sampling data for arsenic and maximum contaminant level (MCL) violation data for 464 CWSs actively operating from 2005–2007 in California’s San Joaquin Valley we ran bivariate tests and linear regression models.

Results

Higher home ownership rate was associated with lower arsenic levels (ß-coefficient= −0.27 μg As/L, 95% (CI), -0.5, -0.05). This relationship was stronger in smaller systems (ß-coefficient= −0.43, CI, -0.84, -0.03). CWSs with higher rates of homeownership had lower odds of receiving an MCL violation (OR, 0.33; 95% CI, 0.16, 0.67); those serving higher percentages of minorities had higher odds (OR, 2.6; 95% CI, 1.2, 5.4) of an MCL violation.

Conclusions

We found that higher arsenic levels and higher odds of receiving an MCL violation were most common in CWSs serving predominantly socio-economically disadvantaged communities. Our findings suggest that communities with greater proportions of low SES residents not only face disproportionate arsenic exposures, but unequal MCL compliance challenges.

Social disparities in nitrate contaminated drinking water in California’s San Joaquin Valley

Journal Paper
Carolina Balazs, Rachel Morello-Frosch, Alan Hubbard & Isha Ray
Environmental Health Perspectives, 119: 1272 – 1278.13
Publication year: 2011

Abstract

Background: Research on drinking water in the United States has rarely examined disproportionate exposures to contaminants faced by low-income and minority communities. This study analyzes the relationship between nitrate concentrations in community water systems (CWSs) and the racial/ethnic and socioeconomic characteristics of customers.

Objectives: We hypothesized that CWSs in California’s San Joaquin Valley that serve a higher proportion of minority or residents of lower socioeconomic status have higher nitrate levels and that these disparities are greater among smaller drinking water systems.

Methods: We used water quality monitoring data sets (1999–2001) to estimate nitrate levels in CWSs, and source location and census block group data to estimate customer demographics. Our linear regression model included 327 CWSs and reported robust standard errors clustered at the CWS level. Our adjusted model controlled for demographics and water system characteristics and stratified by CWS size.

Results: Percent Latino was associated with a 0.04-mg nitrate-ion (NO3)/L increase in a CWS’s estimated NO3 concentration [95% confidence interval (CI), –0.08 to 0.16], and rate of home ownership was associated with a 0.16-mg NO3/L decrease (95% CI, –0.32 to 0.002). Among smaller systems, the percentage of Latinos and of homeownership was associated with an estimated increase of 0.44 mg NO3/L (95% CI, 0.03–0.84) and a decrease of 0.15 mg NO3/L (95% CI, –0.64 to 0.33), respectively.

Conclusions: Our findings suggest that in smaller water systems, CWSs serving larger percentages of Latinos and renters receive drinking water with higher nitrate levels. This suggests an environmental inequity in drinking water quality.

Interpreting the unknown: Uncertainty and the management of transboundary groundwater

Journal Paper
Anita Milman & Isha Ray
Water International, 36: 631 – 645
Publication year: 2011

This paper shows how uncertainty undermines collaborative transboundary groundwater management. Focusing on the Santa Cruz Aquifer, spanning the United States–Mexico border between Arizona and Sonora, the authors describe the uncertainties within the aquifer using interviews and hydrologic studies. We discuss how data requirements and ambiguous interpretations exacerbate these uncertainties, and explain how each country’s water-management culture combines with this uncertainty to create contrasting views on groundwater availability and abstraction impacts. As a result, water managers in both countries predict different impacts from pumping and recharge, and each uses that information discursively to support unilateral policies rather than to promote collaborative management.

Public versus private: Does it matter for water conservation? Insights from California

Journal Paper
Giorgos Kallis, Isha Ray, Julian Fulton & James McMahon
Environmental Management, 45: 177 – 191
Publication year: 2010

Abstract

This article asks three connected questions: First, does the public view private and public utilities differently, and if so, does this affect attitudes to conservation? Second, do public and private utilities differ in their approaches to conservation? Finally, do differences in the approaches of the utilities, if any, relate to differences in public attitudes? We survey public attitudes in California toward (hypothetical but plausible) voluntary and mandated water conservation, as well as to price increases, during a recent period of shortage. We do this by interviewing households in three pairs of adjacent public and private utilities. We also survey managers of public and private urban water utilities to see if they differ in their approaches to conservation and to their customers. On the user side we do not find pronounced differences, though a minority of customers in all private companies would be more willing to conserve or pay higher prices under a public operator. No respondent in public utility said the reverse. Negative attitudes toward private operators were most pronounced in the pair marked by a controversial recent privatization and a price hike. Nonetheless, we find that California’s history of recurrent droughts and the visible role of the state in water supply and drought management undermine the distinction between public and private. Private utilities themselves work to underplay the distinction by stressing the collective ownership of the water source and the collective value of conservation. Overall, California’s public utilities appear more proactive and target-oriented in asking their customers to conserve than their private counterparts and the state continues to be important in legitimating and guiding conservation behavior, whether the utility is in public hands or private.

Urban water supply in India: Status, reform options, and possible lessons

Journal Paper
David McKenzie & Isha Ray
Water Policy, 11: 442 – 460
Publication year: 2009

Abstract

Large numbers of households in cities around the developing world do not have access to one of the most basic of human needs–a safe and reliable supply of drinking water. This paper uses the experience of India as a lens through which to view the problems of access to water in urban areas and the various options available for reform. Using two sets of data from the National Family Health Survey, as well as published and unpublished secondary sources, the paper presents the status of access to drinking water in urban India, the performance of India’s urban water sector compared to other Asian metropolitan regions and the reform efforts that are under way in several Indian cities. A review of these ongoing reforms illustrates some of the political economy challenges involved in reforming the water sector. Based on this analysis, we draw out directions for more effective research, data collection and policy reform. While each country faces unique challenges and opportunities, the scope and range of the Indian experience provides insights and caveats for many low-income nations.

Equity reexamined: A study of community-based rainwater harvesting in Rajasthan, India

Journal Paper
Jaquelin Cochran & Isha Ray
World Development, 37: 435 – 444
Publication year: 2009

Summary

Equity is central to community-based development efforts, but community perspectives on equity are seldom examined in the development literature. This study investigates how equity in a rainwater harvesting program is understood, and practiced in two Rajasthani communities. Drawing on Bourdieu’s concept of symbolic capital, we find that the symbolic capital accrued from contributing to the project is as central to community understandings of equity as the distribution of benefits from the project. We find that a continuing sense of community despite heterogeneity is itself a form of symbolic capital. Community-based valuations of equity thus enable a more catholic approach to costs, and benefits that broadens our knowledge both of equity, and of development.

Women and water in the developing world

Other Writings
Isha Ray
March 20, 2008. In: Encyclopedia of Earth, Cutler J. Cleveland (ed). Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment
Publication year: 2008

The Contested Commons: Conversations Between Economists and Anthropologists

Book
Pranab Bardhan & Isha Ray
Malden and Oxford: Blackwell Publishing.
Publication year: 2008

The Contested Commons explores the theme of common environmental resources from the dual perspectives of economics and anthropology, with a focus on developing countries

  • Contributed readings written by senior scholars in the fields of Economics, Anthropology, and Sociology
  • Looks at the challenges of interdisciplinary work in the social sciences, illustrating the variation in approaches/methodology
  • Focuses on economic security, ecological sustainability, identity formation, and participatory decision-making, particularly in the developing world

An integrated method for evaluating community-based safe water programs and an application in rural Mexico

Journal Paper
Carol de Wilde, Anita Milman, Yvonne Flores, Jorge Salmeròn & Isha Ray
Health Policy and Planning, 23: 452 – 464
Publication year: 2008

Abstract

The burden of diarrhoeal disease remains high in the developing world. Community-based safe drinking water programmes are being promoted as cost-effective interventions that will help reduce this illness burden. However, the effectiveness of these programmes remains under-investigated. The primary argument of this paper is that the biological exposure reductions underlying safe water interventions vary tremendously over space and time, and studies that only report results of intent-to-treat analyses cannot reveal why such programmes succeed or fail. The paper develops a stepwise evaluation framework to characterize, and so analyse, the technical, financial, social and behavioural factors that underlie exposure and mediate the impact of safe water investments. Relevant factors include physical performance of the water system, community capacity to maintain and manage the systems, and the time and budget constraints of households participating in the programme. The approach draws on the public health, community-based resource management, and household choice literatures to identify modifiable points of failure along the causal pathway to programme impact. The evaluation framework is used to assess the performance and impact of UVWaterworks, a community-based water purification system in rural Mexico, 5 years after the programme began. No impact on diarrhoea incidence was found in this case. The assessment method revealed that (a) household priorities and preferences were a key factor in maintaining exposure to safe drinking water sources, and therefore (b) user convenience was a primary leverage point for programme improvement. The findings indicate that a comprehensive examination of the many factors that influence the performance and impact of safe water programmes is necessary to elucidate why these programmes fail or succeed.

Women, water and development

Journal Paper
Isha Ray
Annual Review of Environment and Resources, 32: 421 – 449
Publication year: 2007

Abstract

That women play a central role in the provision, management, and safeguarding of water is one of the four internationally accepted principles of water management. This principle is especially important for the developing world where millions of women lack access to water for their basic needs. The objectives of this chapter are to summarize what is known about women with respect to water and about water with respect to women as well as to provide a sense of the current debates around these themes. A review of the literature suggests that the lack of gender-disaggregated data on the impacts of water policies, and underlying disagreements on how gender and development should be theorized, makes it difficult to reach robust conclusions on which policies can best assure poor women reliable access to water for their lives and livelihoods.

Glossing over the complexity of water

Other Writings
Giorgos Kallis, Michael Kiparsky, Anita Milman & Isha Ray
Science Letters 314: 1387 – 1388, 1 December 2006.
Publication year: 2006

Get the prices right: Water prices and irrigation efficiency

Journal Paper
Isha Ray
. Economic and Political Weekly, August 13 2005: 3659 – 3668
Publication year: 2005

Economists are right when they point out that irrigation water prices are absurdly low compared with their scarcity value, and that at such low prices there is no incentive to conserve. However, it does not follow that raising water prices is the natural next step for developing countries such as India. There are two broad reasons for this conclusion: first, in the near to medium term, canal water prices probably cannot be raised to the point where they significantly affect water demand. The negative impact on farm revenues would be too drastic and the policy would not find broad public support. Second, low water prices are often not the main reason behind the farmers’ water-inefficient crop choices. Moreover, farm-level inefficiencies appear not to be the most significant ones on existing canals, nor are water prices the most significant prices driving irrigation demand. A better first step would be to enforce simple allocation rules – such as per-hectare rations – that would make the scarcity value of water immediately obvious. The analysis in this article is based on a study of one canal system in Maharashtra.

Locational asymmetry and the potential for cooperation on a canal

Journal Paper
Isha Ray & Jeffrey Williams
Journal of Development Economics, 67: 129 – 155
Publication year: 2002

Abstract

Illegal water diversions and lax rule-enforcement are common on irrigation canals. We present a mathematical programming model of a watercourse, calibrated to a canal in Maharashtra on which farmers voted to cooperate to control water theft. The model solution computes the crop choices and profits of individually optimizing farmers who differ in their location. It reveals the spatial distribution of gains and losses from cooperation. It illuminates why voluntary bargaining will rarely achieve an efficient water allocation. It also shows that landless laborers might well be against local cooperation, if the expropriated water nurtures labor-intensive crops.

More from less: policy options and farmer choice under water scarcity

Journal Paper
Isha Ray & Serap Gül
Irrigation and Drainage Systems, 13: 361 – 383
Publication year: 1999

Abstract

In much of the world, fresh water is scarce and getting scarcer. Growing populations, increasing industrialization, and environmental concerns have all put pressure on the water consumed by agriculture. This paper addresses the economic consequences of a permanent reduction in canal water for irrigation. Using detailed cost-of-cultivation data from the Gediz Basin, Turkey, the key questions are: How can farmers best respond to reduced surface water supplies? How can the canal management authorities best distribute this limited water? And,can the demand for water be reduced through input and output price policy? These questions are answered with scenario comparisons under several water availability,crop pattern, price and investment assumptions, for the short and medium time horizons.

Keeping productivity high and water use low requirescoordination between farmers and the water managementauthorities. The analysis shows that, in this region,farmers should keep all their land irrigated at loweryield levels, rather than reduce their cropped areas.The canal managers should opt for a short irrigationseason, rather than an extended season with long dryintervals. Sensitivity analysis on a range of pricesindicates that crop, rather than water prices, affectthe efficiency of water use. The scenarios areevaluated using AGWAT, a spreadsheet-based farm-budgetprogram which is simple and widely applicable. Therange of policy choices considered establishes aframework of analysis for other, potentiallywater-short basins, beyond the Gediz or Turkey.

Evaluation of price policy in the presence of water theft

Journal Paper
27. Isha Ray & Jeffrey Williams
American Journal of Agricultural Economics, 81: 928 – 941
Publication year: 1999

Abstract

Mathematical programming models of “representative” farms are commonly used to evaluate policies such as input subsidies and output price supports. On canals in India, upstream farmers routinely use more irrigation water than allotted. In such circumstances, the programming model should encompass farmers’ locational heterogeneity. Here, a representative watercourse with thirty farms is calibrated to the eight crops, fifteen irrigation turns, yield responses to water, and seepage in Maharashtra. Not only does water “theft” increase the social cost of price policies, but the policies’ increased inducement to theft by upstream farmers leaves those downstream with less water and lower incomes.