Innovations in WASH Impact Measures 2018: Water and Sanitation Measurement Technologies and Practices to Inform the Sustainable Development Goals

The United Nations Sustainable Development Goals (SDGs) were announced with fanfare in September 2015. Updating the Millennium Development Goals (MDGs), the 17 SDGs promise to deliver an ambitious range of global impacts, including “End poverty in all its forms everywhere”; “Ensure access to affordable, reliable, sustainable and modern energy for all”; and “Revitalize the global partnership for sustainable development.”1 The new 2030 Agenda includes water, sanitation, and hygiene (WASH) at its core, with SDG 6 dedicating a commitment to “Ensure availability and sustainable management of water and sanitation for all.” Monitoring progress toward this goal will be challenging because direct measures of water and sanitation service quality and use are either expensive or elusive. However, a continued reliance on household surveys poses limitations that likely overstated water access during the MDG period. The Opportunity Emergent technologies, methods, and data-sharing platforms are increasingly aligned with impact monitoring. Improved monitoring of water and sanitation interventions may allow more cost-effective and measurable results. In many cases, technologies and methods allow more complete and impartial data in time to allow program improvements. In this report, we review the landscape of technologies, methods, and approaches that can support and improve on the water and sanitation indicators proposed for SDG targets 6.1, “by 2030, achieve universal and equitable access to safe and affordable drinking water for all,” and 6.2, “by 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations.” In some cases, technologies and methods are validated and readily available. In other cases, emergent technologies and approaches hold promise but require further field evaluation and cost reductions. The World Health Organization and United Nations Children’s Fund Joint Monitoring Programme (JMP) for Water and Sanitation has developed proposed indicators for measuring progress toward SDG targets 6.1 and 6.2. In chapter 1, authors with the JMP review the rationale for a continued primary reliance on household surveys and censuses because these data sources are readily available from national statistical offices. However, the JMP has also proposed progressively integrating other data sources, when available, including water quality testing, in situ instrumentation, and Earth observations. Notably, the JMP has proposed a “service ladder” monitoring approach, acknowledging the progressive and nonbinary nature of increased access to safe water and sanitation. The highest rung on the ladder for SDG target 6.1, “universal and equitable access to safe and affordable drinking water for all,” focuses on “safely managed drinking water” as measured, when feasible, through direct water quality testing, while lower rungs measure access to “improved” drinking water sources, similar to the approach used in the MDG period. Similarly, hygiene monitoring qualifies “handwashing at home” as the highest service ladder rung, and lower levels examine extra-household services, such as handwashing in schools and health care facilities. The data and insights gained from these improved monitoring approaches are effective only when leveraged toward improved service delivery in the broader context of maximizing public health. The integration of service ladders and consideration of direct service quality and delivery measures are important steps toward credible and actionable data collection. Building on the JMP’s indicator review, in chapter 1 epidemiologists advance the consideration of health impact as a primary driver for water and sanitation monitoring. Reviewing the monitoring approaches used in the MDG period, this chapter highlights the significant gap between “improved” water and sanitation and impacts on health. Constructively, additional measures are proposed including measures of quantity, quality, and sustained access to safe drinking water, including direct and repeated water quality testing, and direct measures of sanitation system integrity and individual use. Fully reconciling the benefits of measurement quality and integrity provided by direct and repeated or continuous measures of water quality, use, and service delivery with the scalability and cost-effectiveness of household surveys is beyond the scope of this report. However, we advance this discussion through the curation of available and emerging technologies, methods, and systems that may enable cost-effective and reliable water and sanitation monitoring. In chapter 2, we review water quality monitoring standards applicable to SDG 6 and the JMP’s proposed water quality approach, and present methods and technologies for monitoring household and community-level microbial and physiochemical contamination. Typically, the most important water quality measures are in most cases microbial contamination, whereas other contamination may be relevant on a regional or local basis. Moving beyond the simple classification of a source as improved or unimproved, testing of actual water quality parameters will provide a better measurement of the exposure of users to harmful waterborne constituents. However, testing water at the source provides only a snapshot of water quality at the point of collection and is not representative of the actual water consumed, which may have been contaminated between the source and the point of consumption or at storage. As such, chapter 2 recommends measuring samples that come from a container from which household members actually drink. An array of methods exists for both laboratory and field-based measurement, all of which have their advantages and limitations. However, with any method, proper quality control and quality assurance guidelines should be adhered to when at all possible. When larger or more systematic testing is being undertaken, working with local authorities such as the ministry of health or local environmental protection agency may be appropriate. Sanitation and hygiene quality measures are, presently, more challenging to measure than water quality. In chapter 3, we review the myriad forms of sanitation and hygiene interventions, and the most relevant measurement characteristics including access, safety, and proper use. An inherent challenge in monitoring sanitation programs is the diversity of behaviors and facilities. Sanitation behaviors encompass defecation, urination, anal cleansing, deposition of children’s feces, deposition of cleansing products, separation of solid and liquid waste, fecal sludge management, handwashing, adherence to sanitation facility use, and menstrual hygiene. Different sanitation facilities separate excreta from human contact with varying degrees of efficacy (for example, open defecation versus a flush toilet connected to a sewer system). Finally, there are additional factors that can influence the level of contamination in a sanitation facility, including latrine cleanliness, whether the latrine is shared or private, and the degree to which all members of a household can access the latrine. These layers of behavior, facility type, and facility characteristics interact dynamically and change in time, making it difficult to determine which sanitation features are most important for reducing human exposure to pathogens. Given this complexity, it is important to identify the sanitation outcomes that minimize exposure to pathogens before exploring the best practices and technologies for monitoring those outcomes. Chapter 3 identifies outcomes that are explicitly or implicitly identified in the SDG target on sanitation and hygiene and the extent to which those outcomes are represented in the proposed service ladders. A variety of innovative practices and technologies are described with specific attention given to their abilities to accurately measure and monitor progress on each outcome. In chapter 4, we describe some limitations of, and alternatives to, traditional measurement methods for measuring water and sanitation use and behavior. Measurement of adoption and compliance with water and sanitation interventions, such as latrines, water pumps, and water filters, has often relied on surveys and observations. However, surveys and other common methods for assessing behavioral practices are known to have certain methodological shortcomings, including poor correlation between observations and self-reported recall. Survey results can also be affected by errors of interpretation on the part of the informant or the enumerator. Data missing because of participant absences or failure to follow up is another source of systematic bias. Additionally, it is known that the act of surveying or observation can itself impact later behavior, a phenomenon known as reactivity or the Hawthorne effect. Structured observation, an alternative to relying on reported behavior in response to surveys, has also been shown to cause reactivity in the target population. Finally, the subjectivity of the outcome studied can strongly influence reporting bias. In chapter 4, we highlight these challenges while proposing direct and indirect measures of behavior and use that can better estimate progress toward SDG 6. Emergent technologies, including water meters, water pump sensors, and latrine motion detectors can improve the objectivity and continuity of data collection. Satellite-based remote sensing and sensors linked to the Internet of Things can be aligned with smartphone-based surveys and online “big data” tools. These technologies and services are reviewed in chapters 5 and 6, and may offer improvements in the collection of, and action on, data from water and sanitation programs. The term “remote sensing” usually describes the collection of data by satellites. In most cases, “remote” refers to spectral imagery collected by cameras and other spectral instruments across a broad range of wavelengths. In the case of Earth observation, satellites take spectral data reflected from the atmosphere and the Earth’s surface. Interpretation of these data (often represented as imagery) requires an understanding of spectral data and physical properties of the Earth and its atmosphere. Interpretation often also requires calibration against data collected on the Earth’s surface or in the atmosphere directly—data from sensors that are in situ rather than remote. In situ instrumentation technologies vary from flow meters and water quality sensors to motion detectors installed in latrines. These sensor technologies can be used either operationally or within a statistical sampling frame. Data can be logged locally for manual retrieval or transmitted over short range to nearby enumerators, or to remote operators and researchers over Wi-Fi, cellular, and satellite networks. Some instrumentation is in common use, while other technologies are emerging. However, given the remote and power-constrained environments and the high degree of variability between fixed infrastructure—including age, materials, quality, servicing, and functionality—any electronic sensor–based solution often either is custom engineered or compensates for these complexities through analytics. For example, a conventional flow meter designed for a rural borehole water distribution scheme would have to address pipe diameter, material, pressure, depth, thread type, and other characteristics that require custom engineering and plumbing, whereas a nonintrusive ultrasonic flow meter may be more easily adapted for a variety of water schemes. Cellular phone–based data collection with online analytics and dissemination is a rapidly growing field for water and sanitation programs. The field of mobile surveys provides a user-friendly platform to easily collect data using a mobile platform rather than a paper-based survey. The mobile platform additionally allows for Global Positioning System (GPS) coordinates, barcode scanning, and photos to be easily associated with a particular sample. The ability to look at photos and confirm GPS coordinates creates both ease of data analysis and surveyor accountability. In chapter 6, a number of electronic data collection and dissemination tools used in WASH programs are reviewed. Looking Forward Each of these myriad monitoring and evaluation methods has its own advantages and limitations. It is often beneficial to leverage more than one method to get a fuller picture of water and sanitation service delivery and adoption behavior. Combined methodologies reinforce the advantages, while also addressing the limitations, of the individual monitoring techniques that compose them. Surveys, ethnographies, and direct observation give context to electronic sensor readings that may be more continuous and objective. Overall, combined methodologies can provide a more comprehensive and instructive depiction of WASH usage. Some of the technologies and methods presented in this report are well established, whereas others hold promise but require extensive field-testing and validation, commercialization, and scaling. Because applications vary widely, we have not attempted to directly compare costs between methods and technologies. Likewise, it is beyond the scope of our report to compare the relative value or reliability of different methods. Instead, we present a menu of options for policy makers, program implementers, and auditors to consider when designing impact measurement efforts.