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HWTS Network Webinar Evaluating household water treatment: from evidence to action

April 27, 2011: 09h30-11h00 (Eastern Standard Time) Summary

Overview In April 2011, the International Network on Household Water Treatment and Safe Storage held its first webinar broadcast – Evaluating household water treatment: from evidence to action.

The webinar sought to answer the following questions: (1) What do we know about use and impacts of household water treatment?

(2) What are the major challenges in effectively targeting those most in need of such treatment?

(3) How can we improve how we measure and compare results?

The webinar included presentations from Daniele Lantagne at Harvard University, and Orlando Hernandez at Academy for Educational Development. Discussion followed, moderated by Bruce Gordon from the World Health Organization during which a number of questions from participants were addressed.1

Presentation 1: Daniele Lantagne, Harvard University

75 individuals participated in the session. This document summarizes the presentations, survey results and key documents mentioned and will be updated shortly to include a summary of discussion and Q&A. Appendix 1 & 2 provide the webinar agenda and list of presentations.

Ms. Lantagne summarized current evidence on the effectiveness of HWTS and addressed issues in scaling up programmatic efforts. She noted that while recent meta-analyses on HWTS show a 35%-47% reduction in diarrheal disease (Fewtrell, 2005; Clasen, 2006; Waddington, 2010), there are a number of worthy critiques which should be considered in future study design to strengthen the evidence base.

The main issues cited include a lack of blinded studies in developing countries, the threat of bias in self-reported incidence of diarrhea, a lack of data on long-term use of HWTS, and the artificial conditions of a laboratory setting under which effectiveness has been assessed. Moreover, the data does not provide clear guidance on which HWTS method is most effective or appropriate in a given context.

Ms. Lantagne also highlighted four key issues hampering the scaling-up of HWTS efforts: i. Use of an effective, appropriate HWTS option: There is a wide array of proven (and unproven)

methods and implementers should carefully review its microbial and health impact, acceptability for local use and scalability;

ii. Correctly and consistently: Compliant use of HWTS has been shown to reduce the incidence of diarrhea, illustrating the importance of keeping it simple and effective;

iii. By the vulnerable target population: The method, distribution strategy and ultimate cost to end-user should be culturally and contextually appropriate for the population at risk; and

iv. On a long-term and sustainable basis: Sustainability requires that the method become accepted practice by the community without intervention or support from external parties.

There have been programs in the development and emergency contexts that have shown microbiological

1 Session host: Maggie Montgomery, WHO; Rapporteur: Ryan Rowe, University of North Carolina at Chapel Hill (UNC).

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and health impacts. These programs use a verified HWTS option, in a culturally acceptable environment, in users with contaminated water, with a distribution and funding strategy.

For HWTS implementers, the current key challenges are measuring the effectiveness of HWTS in the field and sustaining correct and consistent use of effective and appropriate HWTS options. Despite inherent behavioral issues, the burden of responsibility rests at the policy level. Access to clean water is a human right and HWTS is primarily an interim solution not intended to divert government investment in addressing the water and sanitation infrastructure gap.

Presentation 2: Orlando Hernandez, Academy for Educational Development Mr. Hernandez presented an overview of a USAID manual “Access and Behavioral Outcome Indicators for Water, Sanitation and Hygiene” published in February 2010 (Hernandez & Tobias, 2010). The document outlines essential and expanded indicators for the evaluation of WASH interventions in three specific areas: household water treatment and safe storage, hand washing with soap, and sanitation.

Mr. Hernandez focused on the HWTS aspect of the manual and suggested it will be useful for program planners, managers, and evaluators in selecting program indicators, setting annual targets and making program modifications if targets are not reached.

The manual lists 12 indicators for measuring access to water supply and use of HWTS and provides for each a breakdown of the indicator components used for monitoring and evaluation, such as the rationale, data collection and analysis, limitations, use in setting target objectives, example survey questions and calculation methodology.

Three specific indicators are listed as essential to monitoring water supply and use of HWTS: i. % of households that use an improved drinking water source (urban and rural); ii. % of households practicing correct use of recommended household water treatment

technologies; and iii. % of households storing treated water in safe storage containers.

A brief case study of HWTS in Ampara, Ethiopia was presented. This study is currently being prepared for publication and is not yet available for dissemination (Hernandez et al, in press).

The manual was prepared by AED with funding support from USAID. It can be downloaded from http://www.hip.watsan.net/page/4148.

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Q&A Discussion Session: Moderated by Bruce Gordon, WHO

The following includes the list of questions submitted prior to the Webinar as well as those raised during the session itself. Bruce Gordon facilitated the Q&A which is summarized below. Prior to Webinar Cost and Benefits of HWTS Q: (Paul Osborn, 300 in 6) We often assert that adoption of HWTS – often through social marketing has a dramatic impact on incidence of illness, and thus has a massive impact on health expenditure in national budgets. What studies or other evidence exist of this? Can we make such findings more persuasive? A: There are a number ways by which economic benefits could be demonstrated. One means is through health impact studies which document diarrheal cases adverted. Using such figures and making certain assumptions, cost savings could be calculated in regards to treatment adverted, time saved not caring for sick, increased school attendance, etc. Studies which have quantified the costs and benefits of water and sanitation interventions and health outcomes include Hutton & Haller (2004) and Prüss-Üstün et al (2008). A number of meta-analyses do consider the specific health impacts of HWTS, the most recent being the paper by Waddington et al (2009). There are dozens of individual HWTS health impact studies but given the variability in study design combined with the different disease burden and development contexts in which HWTS has been implemented it is difficult to make broad economic conclusions. The persuasiveness of the health impact studies could be increased by having more "blinded" trials complimented by regular monitoring and evaluation of HWTS using standard, agreed upon approaches and indicators. A starting point for such indicators is provided in the draft toolkit for monitoring and evaluation of HWTS, which has been circulated for comment and is currently being revised. Scaling-up and role of HWTS in overall water, sanitation and health improvements Q: (Paul Osborn 300 in 6) The necessary massive adoption of HWTS – often called scaling-up – can only happen if the dynamism of the private sector can be blended with the responsibilities of the public sector, and given incentives to thrive. What legislative framework can, again realistically, be applied to allow this process to flourish? A: The establishment of national HWTS policies is one important factor in scaling up. This requires collaboration among many different government ministries (water, health, education, technology) and often establishing new channels of communication and decision-making. Implementation of such policies, in turn, requires collaboration with the private sector, which is often responsible for manufacturing HWTS and in certain instances sales and distribution. Ethiopia is one example of a country that has an emerging public private partnership (PPP) concerning HWTS that provides a policy mechanism for raising awareness, penetrating the market and increasing advocacy efforts. Monitoring and evaluation Q: (Jeff Albert, Aquaya) Re: Orlando's slides on Ethiopia: Where are the HHs located within Ethiopia (rural, urban). How were they sampled? Was this simply two cross-sectional surveys (one in 2008 and a second in 2010)? And can he explain the vast discrepancy between the sample sizes at baseline vs. endline? In the HWTS portion, baseline n=176 and endline n=501. Then in the storage portion, baseline n=1586 and endline n=477 A: (Orlando Hernandez) The sample comes from rural areas in the Amhara Region where the project was implemented. That region is 80% rural. The urban population lives mainly in the city of Bahar Dir. We did not visit any household in the city per se, but there were some households that were visited in the rural areas of the district where this city is located. The samples have different sizes to begin with because we dropped one of the study groups in the endline because there was no need for that group anymore. At the baseline we had three levels of program intensity: high, intermediate and low. However, during implementation the adoption of the program content became mandatory across the intermediate districts in the region and the intermediate intensity did not make sense anymore. The differences in

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numbers between those that treat and those that store is explained by the fact that the storage number reflect those that treat as well as well as those that do not treat their drinking water. Not everybody treats drinking water, but many households store drinking water whether they treat it or not. Q: (Henk van Norden UNICEF, Regional Office for SE Asia) Has anyone looked at the impact on households that report treating their drinking water, in DHS or MICS surveys? Is there a difference in the prevalence of reported diarrhoea among children in those households? A: Household water treatment is one of the items measured in the Key Indicator Survey (KIS), a tool developed by the MEASURE DHS program to provide data comparable to a national Demographic and Health Survey (DHS). The DHS collects information on child health, including diarrheal disease. Thus, while both HWT and diarrheal disease are measured, attributing impact requires following both users of HWTS and a valid control group, or a segment of the population not using HWTS that is similar in all significant respects (education, environment, wealth) to those using HWTS, over time. Such a design is not currently being undertaken by these survey methods. For more information about the KIS, visit: http://www.measuredhs.com/aboutsurveys/kis.cfm. For more information about DHS’s child health focus, visit: http://www.measuredhs.com/topics/childhealth/start.cfm. The UNICEF Multiple Indicator Cluster (MICs) survey also looks at household water treatment and childhood diarrhea but again does not allow for an analysis of "impact" because the study design does not include a valid comparison group nor measure the two groups over time. Learn more about the MICs at: http://www.unicef.org/statistics/index_24302.html. Another source of information on household water treatment is the rapid assessment of drinking water quality (RADWQ) surveys which are conducted through the WHO/UNICEF Joint Monitoring Program for Water Supply and Sanitation. These surveys measure HWTS and fecal indicators in drinking water such as thermotolerant coliforms and therefore provide a measure of use or outcomes from HWTS programs. For more information on the RADWQ, please visit http://www.wssinfo.org/water-quality/introduction/. Treatment Options Q: (Ian Balam Fundacion Cantaro Azul) As an organization in the field we find ourselves with the dilemma of justifying our "disinfection programs" in regions where the water has other dangerous contaminants like pesticides, etc. Has there been any agreement on the part of WHO, CDC, etc, with regards to justifying such interventions even though we are not solving other health problems on the long run? How do large organizations communicate to the rural communities the short term benefits vs. the potential risks on the long term due to chemicals in their water sources? A: This is an important question and the tradeoffs of different household water treatment options as well as short term HWTS solutions compared to longer-term investments in community water supplies should be considered carefully. There is no "one answer" to such a question and rather organizations should examine each situation in particular. The WHO recommends using a risked-based framework to identify, prioritize and and minimize key waterborne health hazards, both microbial and chemical. Microbial risks are acute and significant adverse health consequences may arise after a single exposure. Chemical risks usually effect health only after prolonged chronic exposure. Thus the potential health consequences of microbial contamination are such that its control must always be of paramount importance and must never be compromised. A risk based approach is the basis for the WHO Guidelines for Drinking-water Quality (WHO, 2008). Water safety plans (WSPs) provide a clear framework for undertaking such an analysis to assess risks and consistently ensure the safety of drinking water supplies; in 2009 the WHO published a manual on developing WSPs (Bartram et al, 2009). Q: (Jane Thapa, New York State Department of Health - Bureau of Water Supply Protection) Any comments on the LifeStraw? A: The LifeStraw is a drinking water treatment method that relies on filtration to remove pathogens, including bacteria and protozoa. A recent randomized controlled trial of the Lifestraw Personal in Ethiopia

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found that in intervention households filtered water was free of thermotolerant coliforms. However after five months only 13% of participants reported consistent use (Boisson et al., 2009). Q: (Alex Hinga, University of Nairobi)

I would like you to address the effects of temperature on microbial growth in stored household water. I am carrying out research on drinking water quality and have realized that most households in the study area store their water near where cooking takes place. A: While typical waterborne pathogens are able to persist to varying degrees in drinking-water, most do not grow or proliferate in water. Persistence is affected by several factors, including water temperature, and decay is usually faster at higher temperatures. However, under most circumstances, the stored water in containers near cooking areas is likely not to increase substantially in temperature due to the given volume and proximity to heat, and thus any changes in microbial concentrations would be similar to containers stored elsewhere. It is important to note that viruses and the resting sages of parasites are unable to multiply in water. For more information refer to the WHO Guidelines on Drinking-water quality (GDWQ). The 4th Edition of the GDWQ will be released and available online in July 2011. Q: (Alex Hinga, University of Nairobi)

In addition, what could be the cheapest and efficient method of removing nitrates from drinking water in a low income neighbourhood? A: The efficacy of removal of nitrates depends on the technology used but the effectiveness would depend on a variety of social, economic and health behaviour factors concerning correct and consistent use. Refer to Chapter 8 of the GDWQ for specific estimates of nitrate removal based on different water treatment methods. In addition, in regards to the selecting the most suitable method for a specific low-income area, some criteria and factors to guide this decision are provided in the WHO document "Evaluating household water technologies: health based targets and microbiological performance specifications". The document will be online by mid-July 2011. During Webinar

Q: (Sibonginkosa Maposa) I lived in Zimbabwe when the urban water supply systems collapsed and had an opportunity to observe household treatment evolve with minimal NGO promotion. It so happened that at the time I was also completing my Master thesis looking at the evidence on the success of HWTS. My feeling at the time was that user acceptance and uptake had largely been addressed as a secondary issue. Nonetheless, it was possible from the field evidence then, to identify the key determinants of uptake, some have been touched on today. A: Bruce Gordon from WHO thanked the respondent for the comment and national perspective on how market forces can influence uptake of HWTS. Hans Mosler from EAWAG further commented that there are two publications on acceptance and use of SODIS in Zimbabwe (Kraemer and Mosler, 2010; Kraemer and Mosler, 2011). These are listed in the references section of this document.

Q: (Christina Keller, Triplequest) Have you seen the study on Sustainability of Household Water Treatment by Mark Sobsey et al (2008) and if so, what do you think of it? (Link to study provided in References section) A: The paper stresses the importance of sustainability of HWTS and highlights that except for boiling, no other methods have achieved sustained, large-scale use. The most effective, widely promoted and used POU HWTs are critically examined according to specified criteria for performance and sustainability. Q: (Jeff Albert, Aquaya) Orlando, 2008-2010 HWT slide for Ethiopia: how can we compare the baseline and endline when they are NOT the same study population, if n=156 in 2008 and n=501 in 2010)

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A: (Orlando Hernandez) These are samples that represent households located in the districts where the sample was drawn. The absolute numbers of households reporting treatment has increased. Q: (Yirgalem Solomon, UNICEF, Eritrea) In Eritrea we are planning to make a pilot HWTS in three villages and we would like to ask the presenters their advice on how to start? What are the key issues that we should consider?

A: The CDC has developed a guide to establishing community safe water programs (Lantagne & Gallo, 2008) – the introductory chapter lists some key steps to program development, such as a community assessment, and identification of existing water resources. A community assessment will help to understand community priorities and potential willingness to use and maintain HWTS as well as behaviors related to use of water and sanitation resources. It will also help to identify local stakeholders who can be partners in program implementation. Commitment and support from the community, including local government, is usually a crucial factor in determining program sustainability. Identifying existing water resources is an important technical matter that affects the choice of an appropriate HWTS technology or method based on the risks posed by the existing water supply system. These supplies and risks may vary by season (i.e. during the rainy season surface water sources may be used while in the dry season wells may be preferred). The WSP Manual provides a framework to assess these risks as well as guidance on implementation (Bartram et al, 2009). Once these risks have been assessed, other factors to consider include effectiveness in removing pathogens of concern, user acceptability, cost and local availability of replacement parts or consumables and educational, training and/or promotional support required for implementation and sustained operation over time. Q: (Alex Hinga) To Daniele Lantagne; Apart from targeting vulnerable populations, how effective are measures that target specific microbes i.e rotavirus/ e. coli which cause >40% of all diarrhoea cases? A: The burden of diarrheal disease attributable to specific pathogens varies by region and season and therefore it is difficult to make generalizations about particular HWT methods. Recent evidence from a global study known as the Global Enteric Multi-Cluster Study (GEMS) taking place in seven different developing countries suggests that rotavirus contributes to 10-25% of diarrheal disease cases in young children (Levine, 2009). The preliminary findings from GEMS suggest that the three main classes of pathogens (viruses, bacteria and protozoa) all contribute to diarrheal disease in children. As detailed in the WHO document Evaluating household water treatment options: Health based targets and microbiological performance specifications (WHO, 2011) all three classes of pathogens are important. HWT technologies should therefore remove all three classes of pathogens. For further details refer to the above mentioned document. It is also important to note that E. coli is a faecal indicator and provides evidence of recent faecal contamination but only certain strains of E. coli (i.e 0157:H7) are pathogenic. In certain areas where there cause of diarrheal disease is known (such as during a cholera outbreak) some treatment methodologies would be more efficacious than others in removing pathogens and the effectiveness would depend on consistent and correct use. Q: (Johanna Felix, Solvatten) How do you become a part of the research programmes studying HWTS?

A: A variety of different network participating organizations are conducting research on HWTS. One place to start would be to contact specific researchers who have posted items on EzCollab or whose papers are found there. Another idea is to send a short note for inclusion in the monthly Network newsletter or to be posted on the listserv detailing the geographic and thematic areas of your organization's research focus and qualities you are looking for in a researcher/research institution.

Q: (Bolu Onabolu) What are your thoughts Orlando and Daniele on the absence of the focus on the linkage between environmental sanitation and the efficacy of HWTS? Don't we need to talk about sanitation and hygiene and the effect of the environmental setting when discussing HWTS?

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A: Certainly it is important to consider other transmission pathways of diarrheal disease in the home which could influence the effectiveness of HWTS. The well-known F-diagram, first developed by Wagner & Lanoix (1958) and described in a recent UN-Water Factsheet (2008) outlines the faecal-oral transmission route through five “F”s, whereby pathogens can be passed on to a human host by way of contact with contaminated faeces through fingers, food, fluids, flies or fields. As household water treatment and safe storage address just two of these routes (fluids and fingers), other water, sanitation and hygiene-related interventions are still critical to reducing exposure to other known risk factors in a given environment. For example, if the existing water supply has low levels of contamination and the household environment is hygienic, the additional benefit of HWTS and impact on health may be minimal (Eisenberg et al, 2007). Therefore, given the inter-related nature of water, sanitation and hygiene and multiplicity of diarrheal disease pathways, when starting a project in a specific location, one should investigate these pathways to see if HWTS might be an appropriate intervention. It is yet unclear whether there is a cumulative effect of different hygiene interventions. Conceptually, it makes sense but empirically the data to substantiate the claim is limited. Additional studies are currently underway to address this issue. Q: (William Feenor, UCDavis) Ceramic pot filters usually use colloidal silver as an additional treatment. Are there no field studies on just using colloidal silver directly as a treatment? A: The antimicrobial effects of silver in various forms have been noted for centuries. There is limited data, however, from field studies detailing the use of silver as a treatment technology. In addition many questions remain regarding the toxicity of silver. Refer to Chapter 12 of the GDWQ (WHO, 2008) for further information. Q: (Tamara Lindner) How do the various technologies compare to each other in efficacy and acceptability to users?

A: There is a range of efficacy of HWT, as measured by their performance against the three main classes of pathogens in a controlled laboratory environment. The forthcoming WHO document Evaluating household water treatment options: Health based targets and microbiological performance specifications provides details on how to measure performance and establish health-based targets. The effectiveness of HWT, or performance in the field, also varies. Estimated reductions of waterborne bacteria, viruses and protozoan parasites by the main types of HWT technologies are summarized in the table provided in Appendix 3. This table was extracted from the GDWQ (WHO, 2008) and is also included in the forthcoming WHO document mentioned above. Acceptability will vary according to the local context (social, cultural, economic factors, availability of spare parts and consumables) and requires careful consideration before implementing HWTS programs.

Q: (Josiah Mukutiri) The indicators were developed based on certain assumptions which of course are based on behaviour and with that in mind how easy is it to adopt this manual different environments? A: The indicators in the USAID manual (Hernandez & Tobias, 2010) are meant for settled populations and adjustments to the indicators are needed in the case of nomadic and displaced populations as well as those living in emergency situations. In general, in conducting M&E, organizations should seek to select indicators that are most relevant to the local situation and also attempt to pilot test the indicators before using them on the targeted population to determine their reliability. The manual includes a set of questions that may be used to track the indicators. However, answers to those questions are not necessarily comprehensive. There may be, for example, local water treatment options which are not effective, but which are used by residents. The list of options for water treatment technologies or practices may need to be modified accordingly. Q: (Peter Bernstorff, Lifestraw) Hi Maggie, can we get an update on the WHO guidelines that are under review, and when they will be published?

A: The 4th edition of the WHO Guidelines for Drinking-water Quality is now complete and will be available on the WHO website in July. In addition, the companion document, Evaluating household water

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treatment options: health-based targets and micrbiological perforamance specifications, is complete and will also be available online in July.

Q: (Yemane Gebreegziabher, Ethiopia) My question goes to Daniele. Thanks for the nice presentation. What I see as a challenge in regards to household water treatment technologies in many developing nations is the financial limitations and the importance of promoting HWTS. For example, about 60% of the individuals in my region for example have never heard of the household water treatment technologies. What do you suggest for changing this? A: The success of HWTS relies on the cooperation of many different stakeholders (private sector, government, NGOs, local community organizations, schools), which together can help in raising awareness and providing the enabling environment needed to sustain HWTS. Translating policy initiatives into action will require other stakeholders at the local and regional level to become involved and work together to create a culture of water treatment. For example, in Ethiopia, an emerging public-private partnership for HWTS is working to address three main areas: community awareness, marketing and sales, and enabling environment and thus contribute to an increase in awareness. The Government of Ethiopia has now included HWTS in its National Drinking Water Quality Monitoring and Surveillance Strategy, further increasing the visibility of HWTS. Social marketing can also help to build general awareness of product availability. Programs run by Population Services International have shown that time since program initiation is the biggest factor in terms of knowledge and sales. People will know someone who uses it and people will have tried it at least once. Consistent use of WaterGuard is generally about 5-15% in these countries. Medentech has reported that commercial sales of Aquatabs are higher in countries where social marketing is conducted. However, although social marketing helps to create a knowledge base, a culture and a local market for the product, it is not clear whether the message is getting to those who need it most. Q: (Claire Davis, University of Wisconsin) Where is this manual available?

A: The USAID manual can be downloaded at: http://www.hip.watsan.net/page/4148.

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Summary of Survey Results A short post-webinar survey was conducted to collect feedback to address technical issues, improve user experience and identify topics of interest for future webinars. The highlights of the results are as follows:

­ Response rate: 30 webinar registrants responded; one-third from developing countries (all in Africa)

­ Technical issues: Nearly half reported no issues; those who did experienced mainly audio disruption

­ Format: Participants expressed interest in case studies, roundtable discussions, inclusion of

citations/references, more interaction between participants and presenters, ability to view questions

submitted by other audience members, inclusion of perspectives from the field and government

­ Topics of interest: Understanding the range of HWT options, behavioral issues (e.g. compliance

and proven promotion techniques), policy and regulatory issues, scaling up and sustainability

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References

Arnold, B.F., & Colford, J.M.(2007). Treating water with chlorine at point-of-use to improve water quality and reduce child diarrhea in developing countries: a systematic review and meta-analysis. American Journal of Tropical Medicine and Hygiene, 76(2):354-64. Download at: http://www.ajtmh.org/content/76/2/354.long.

Bartram, J., Corrales, L., Davison, A., Deere, D., Drury, D., Gordon, B., Howard, G., Rinehold, A., & Stevens, M. (2009). Water safety plan manual: step-by-step risk management for drinking-water suppliers. World Health Organization: Geneva. Download at: http://whqlibdoc.who.int/publications/2009/9789241562638_eng.pdf.

Boisson, S., Schmidt, W-P., Berhanu, T., Gezahegn, H., & Clasen, T. (2009). Randomized controlled trial in rural Ethiopia to assess a portable water treatment device. Environmental Science & Technology, 43 (15), pp 5934–5939. Download at: http://www.ncbi.nlm.nih.gov/pubmed/19731700.

Clasen, T. (2009). Scaling Up Household Water Treatment Among Low-Income Populations. World Health Organization. Download at: http://www.who.int/household_water/research/household_water_treatment/en/index.html

Clasen, T., McLaughlin, C., Nayaar, N., Boisson, S., Gupta, R., Desai, D.,& Shah, N. (2008). Microbiological effectiveness and cost of disinfecting water by boiling in semi-urban India. American Journal of Tropical Medicine and Hygiene, 79(3):407-13. Download at: http://www.ajtmh.org/content/79/3/407.short.

Clasen, T. Roberts, I., Rabie, T., Schmidt, W. Cairncross, S. (2006). Interventions to improve water quality for preventing diarrhoea (A Cochrane Review). Cochrane Database of Systematic Reviews 2006, Issue 3. Download at: http://www2.cochrane.org/reviews/en/ab004794.html.

Clasen, T., Thao, D., Boisson, S., & Shipin, O. (2008). Microbiological effectiveness and cost of boiling to disinfect drinking water in rural Vietnam. Environmental Science & Technology, 42(12):4255-60. Download at: http://www.ncbi.nlm.nih.gov/pubmed/18605541.

Eisenberg, J.N., Scott, J.C., & Porco, T. (2007). Integrating disease control strategies: balancing water sanitation and hygiene interventions to reduce diarrheal disease burden. American Journal of Public Health, 97(5):846-52. Download at: http://www.ncbi.nlm.nih.gov/pubmed/17267712.

Fewtrell, L., Kaufmann, R. B., Kay, D., Enanoria, W., Haller, L., & Colford, J. M. (2005). Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: A systematic review and meta-analysis. The Lancet Infectious Diseases, 5(1), 42-52. Download at: http://www.ncbi.nlm.nih.gov/pubmed/15620560.

Hernandez, O., Rosenbaum, J., & Faris, K. (in press). Results from Working at Scale for Better Sanitation and Hygiene in Amhara, Ethiopia: Baseline and Endline Comparisons of Institutional, Household, and School Surveys. Hygiene Improvement Project.

Hernandez, O. & Tobias, S. (2010). Access and Behavioral Outcome Indicators for Water, Sanitation, and Hygiene. Hygiene Improvement Project. Download at: http://www.hip.watsan.net/page/4148.

Hunter, P. (2009). Household water treatment in developing countries: comparing different intervention types using meta-regression. Environmental Science & Technology, 43(23), 8991–8997. Download at: http://www.ncbi.nlm.nih.gov/pubmed/19943678.

Hutton, G,, & Haller, L. (2004) Evaluation of the costs and benefits of water and sanitation improvements at the global level. World Health Organization: Geneva. Download http://www.who.int/water_sanitation_health/ wsh0404/en/.

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Kraemer, S. M., & Mosler, H.-J. (2011). Factors from the Transtheoretical Model differentiating between Solar Water Disinfection (SODIS) user groups. Journal of Health Psychology, 16(1), 126–136. Download at: http://sozmod.eawag.ch/publications.php.

Kraemer, S.M. and Mosler, H.-J. (2010). Persuasion factors influencing the decision to use sustainable household water treatment. International Journal of Environmental Health Research, 20(1), 61-79. Download at: http://sozmod.eawag.ch/publications.php.

Lantagne, D. & Gallo, W. (2008). Safe Water for the Community: A Guide for Establishing a Community-Based Safe Water System Program. Download at: http://www.ehproject.org/PDF/ehkm/cdc-safewater_community.pdf.

Levine, M. (2009). “Global Enteric Multi-center Study: Diarrheal Disease in Infants and Young Children In Developing Countries.” Presentation at Global Vaccine Research Forum in Mali on Dec. 9 2009. Download at: http://www.who.int/vaccine_research/documents/Keynote_Levine_presentation.pdf.

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Sobel, J., Mahon, B., Mendoza, C.E., Passaro, D., Cano, F., Baier, K., Racioppi, F., Hutwagner, L., & Mintz, E. (1998). Reduction of fecal contamination of street-vended beverages in Guatemala by a simple system for water purification and storage, handwashing, and beverage storage. American Journal of Tropical Medicine and Hygiene, 59(3):380-387. Download at: http://www.ajtmh.org/content/59/3/380.full.pdf.

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Waddington, H., Snilstveit, B., White, H., Fewtrell, L. (2009). Water, sanitation and hygiene interventions to combat childhood diarrhoea in developing countries. International Initiative for Impact Evaluation. Download at: http://www.3ieimpact.org/admin/pdfs2/17.pdf.

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WHO (2008). Guidelines for Drinking Water Quality. 3rd edition, Incorporating the First and Second Addenda. World Health Organization: Geneva. Download at: http://www.who.int/water_sanitation_health/dwq/gdwq3rev/en/index.html.

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Appendix 1 – Webinar Agenda

15h15 – 15h30 Log in

15h30 – 15h35 Introductions and technical issues Maggie Montgomery, WHO

15h35 – 15h40 Webinar objectives, outputs and format

Bruce Gordon, WHO 15h40 – 16h00 Evidence of use and impact

Daniele Lantagne, Harvard University 16h00 – 16h00 Transition between speakers

Bruce Gordon, WHO 16h05 – 16h25 Measuring Water Treatment and Storage Practices

Orlando Hernandez, WASHPlus Program, AED 16h25 – 16h55 Question and Answers

Moderator: Bruce Gordon, WHO 16h55 – 17h00 Session Wrap-up

Maggie Montgomery, WHO

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Appendix 2 – Presentations

Presenter: Daniele Lantagne, Harvard University

Title: Evidence of use and impact

Summary: Current evidence on effectiveness of HWTS and issues hindering scaling up of programming efforts

Download: http://waterinstitute.unc.edu/media/HWTS_Network_Webinar_-_April_2011_-_Daniele_Lantagne_Presentation.pdf

Presenter: Orlando Hernandez, Academy for Educational Development

Title: Measuring Water Treatment and Storage Practices

Summary: Overview of HWTS aspects of a USAID manual “Access and Behavioral Outcome Indicators for Water, Sanitation and Hygiene” published February 2010.

Download: http://waterinstitute.unc.edu/media/HWTS_Network_Webinar_-_April_2011_-_Orlando_Hernandez_Presentation.pdf

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Appendix 3 – Estimates of baseline and maximum effectiveness of selected HWT technologies against microbes in water (extracted from WHO, 2008)

Treatment process

Enteric pathogen group

Baseline removal (LRVa)b

Maximum removal (LRV)c Notes

Chemical disinfection Free chlorine disinfection

Bacteria 3 6 Turbidity and chlorine-demanding solutes inhibit this process; free chlorine × time product predicts efficacy; not effective against C. parvum oocysts

Viruses 3 6 Protozoa, non-Crypto-sporidium

3 5

Crypto-sporidium

0 1

Membrane, porous ceramic or composite filters Porous ceramic and carbon block filtration

Bacteria 2 6 Varies with pore size, flow rate, filter medium augmentation with silver or other chemical agents

Viruses 1 4 Protozoa 4 6

Membrane filtration Bacteria 2 MF; 3 UF, NF or RO

4 MF; 6 UF, NF or RO

Varies with membrane pore size (micro-, ultra-, nano- and reverse osmosis filters), integrity of filter medium and filter seals, and resistance to chemical and biological (“grow-through”) degradation

Viruses 0 MF; 3 UF, NF or RO

4 MF; 6 UF, NF or RO

Protozoa 2 MF; 3 UF, NF or RO

6 MF; 6 UF, NF or RO

Fibre and fabric filters (e.g., sari cloth filters)

Bacteria 1 2 Particle or plankton association increases removal of microbes, notably copepod-associated guinea worm Dracunculus medinensis and plankton-associated Vibrio cholerae; larger protozoa (>20 µm) may be removed; ineffective for viruses, dispersed bacteria and small protozoa (e.g., Giardia intestinalis, 8–12 µm, and Cryptosporidium parvum, 4–6 µm)

Viruses 0 0 Protozoa 0 1

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Treatment process

Enteric pathogen group

Baseline removal (LRVa)b

Maximum removal (LRV)c Notes

Granular media filters Rapid granular, diatomaceous earth, biomass and fossil fuel-based (granular and powdered carbon, wood and charcoal ash, burnt rice hulls, etc.) filters

Bacteria 1 4+ Varies considerably with media size and properties, flow rate and operating conditions; some options are more practical than others for use in developing countries

Viruses 1 4+ Protozoa 1 4+

Household-level intermittently operated slow sand filtration

Bacteria 1 3 Varies with filter maturity, operating conditions, flow rate, grain size & filter bed contact time

Viruses 0.5 2 Protozoa 2 4

Solar disinfection Solar disinfection (solar UV radiation + thermal effects)

Bacteria 3 5+ Varies depending on oxygenation, sunlight intensity, exposure time, temperature, turbidity and size of water vessel (depth of water)

Viruses 2 4+ Protozoa 2 4+

UV light technologies using lamps UV irradiation Bacteria 3 5+ Excessive turbidity and certain

dissolved species inhibit process; effectiveness depends on fluence (dose), which varies with intensity, exposure time, UV wavelength

Viruses 2 5+ Protozoa 3 5+

Thermal (heat) technologies Thermal (e.g., boiling)e Bacteria 6 9+ Values based on vegetative cells;

spores are more resistant to thermal inactivation than vegetative cells; treatment to reduce spores by boiling must ensure sufficient temperature & time

Viruses 6 9+ Protozoa 6 9+

Coagulation, precipitation and/or sedimentation Simple sedimentation Bacteria 0 0.5 Effective due to settling of particle-

associated and large (sedimentable) microbes; varies with storage time and particulates in the water

Viruses 0 0.5 Protozoa 0 1

Combination treatment approaches Flocculation/ disinfection systems (e.g. commercial powder sachets or tablets)

Bacteria 7 9 Some removal of Cryptosporidium possible by coagulation Viruses 4.5 6

Protozoa 3 5

a Log10 reduction value, a commonly used measure of microbial reduction, computed as log10 (pre-treatment concentration) – log10 (post-treatment concentration). b Baseline reductions are those typically expected in actual field practice when done by relatively unskilled persons who apply the treatment to raw waters of average and varying quality in developing countries and where there are minimum facilities or supporting instruments to optimize treatment conditions and practices. c Maximum reductions are those possible when treatment is optimized by skilled operators who are supported with instrumentation and other tools to maintain the highest level of performance in waters of predictable and unchanging quality. d MF = microfiltration; UF = ultrafiltration; NF = nanofiltration; RO = reverse osmosis e Heat pastuerization is another example of a thermal technology. For further explanation of the process and references refer to Appendix 2, Termal (heat-based technologies).