Costs and Willingness to Pay for Pit Latrine Emptying Services in Kigali, Rwanda

Journal paper
Zachary Burt Rachel Sklar and Ashley Muspratt
Int. J. Environ. Res. Public Health 2019, 16(23), 4738;
Publication year: 2019

Kigali, Rwanda lacks a centralized sewer system leaving residents to choose between on-site options; the majority of residents in informal settlements use pit latrines as their primary form of sanitation. When their pits fill, the pits are either sealed, or emptied; emptying is often done by hand and dumped in the environment, putting the residents and the broader population at risk of infectious disease outbreaks. In this paper, we used revealed and stated preference models to: 1) estimate the demand curve for improved emptying services 2) evaluate household preferences and the willingness to pay (WTP) for different attributes of improved emptying services. We also quantify the costs of improved service delivery at different scales of production.  The study included 1167 households from Kigali, Rwanda across 30 geographic clusters. Our results show that at a price of US$79 per pit, 15% of all pits would be emptied by improved emptying services, roughly the rate of manual emptying currently. Grouping empties by neighborhood and ensuring each truck services an average of four households per day would could reduce production costs to US$44 per empty, ensuring full cost coverage at that price. At a lower price of US$24, we estimate that sealing of pits might be fully eliminated, with full coverage of improved emptying services for all pits; . this would require a relatively small subsidy of US$20 per empty. Our results show that households had strong a preferences for fecal sludge (FS) treatment, formalized services (which include worker protections), and distant disposal. Results from the study indicate a few key policies and operational strategies that can be used for maximizing the inclusion of low-income households in safely managed sanitation services, while also incorporating household preferences and participation.

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

Journal paper
Burt, Z., Ercümen, A., Billava, N., Ray, I.
World Development, Volume 109, Pages 121-133
Publication year: 2018


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 socioeconomic 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.

User preferences and willingness to pay for safe drinking water: Experimental evidence from rural Tanzania

Journal paper
Burt, Z., Njee, R.M., Mbatia, Y., Msimbe, V., Brown, J., Clasen, T.F., Malebo, H.M. & Ray, I
Social Science & Medicine, 173, 63–71
Publication year: 2016


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 poorquality, and sometimes turbid, drinking water sources.

Towards Gender Equality through Sanitation Access

Discussion Paper
Burt, Z., Nelson, K., and Ray, I
Discussion Paper. UN Women Discussion Paper Series. UN Women
Publication year: 2016

This discussion paper 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.

We cover sanitation design, planning and financing for hygienic defecation, and for relieving oneself during the day at work or school. These needs are sometimes euphemistically referred to as nature’s “long call” (defecation) and “short call” (urination); the absence of safe facilities for these needs disproportionately affects women and girls. In addition, women and adolescent girls menstruate, and they need safe sanitation services to manage, hygienically and with dignity, this “monthly call”. We review the findings of the small but rapidly growing literature on menstrual hygiene management, with emphasis on menstruation management and a girl’s right to education. Finally, we review the work and life conditions of those working the “back-end” of the sanitation system, such as manual scavengers and sanitation workers. The paper concludes that safe sanitation is a gateway service for dignity, health and gender equality. In particular, sanitation in public or shared spaces must become a priority-planning sector for sustainable development.

This paper was featured at an event on Emerging Issues in Gender and WASH held during the 60th Session of the Commission on the Status of Women in 2016.

Upgrading a Piped Water Supply from Intermittent to Continuous Delivery and Association with Waterborne Illness: A Matched Cohort Study in Urban India.

Journal paper
Ercumen, A., Arnold B., Kumpel E., Burt Z., Ray I., Nelson K., and Colford J.M.
PLoS Med 12, no. 10
Publication year: 2015



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.


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

Conference paper
Amrose, S., Burt, Z., Ray, I. (co-authors)
Annual Review of Energy and Resources
Publication year: 2015


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.

A study of the consumption pattern in a continuous water service demonstration zone and bulk water demand forecasting for Hubli-Dharwad, India

Journal paper
Jayaram, KP., Burt, Z. and Kumar, BM.
Journal of Water, Sanitation and Hygiene for Development (2015) 5 (2): 201-212.
Publication year: 2015

In the year 2008, the Karnataka Urban Water Sector (KUWS) Improvement Project brought continuous water service (CWS) to a demonstration zone in the twin cities of Hubli-Dharwad, India. Scale-up of CWS for the rest of the city has been authorized and the initial stages of construction are currently in progress. We compared the historical consumption pattern in the CWS demonstration zone of Hubli with system capacity. We found that demand in the demonstration zone has stayed within system capacity and below the national standards for adequate supply. We developed two forecast models of bulk water demand under CWS and compared forecasts with planned future system capacity. In the case of full scale-up of CWS to the rest of Hubli-Dharwad, our forecasts indicate that planned system capacity may be insufficient to meet bulk demand. These forecast models can be adopted by similar mid-sized cities in India.

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

Journal paper
Burt, Z. and Ray, I.
Water Alternatives 7(1): 106-120
Publication year: 2014


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.