TECHNICAL AND SOCIAL EVALUATION OF THREE ARSENIC-REMOVAL TECHNOLOGIES IN NEPAL By Georges Tabbal B.Eng Civil Engineering McGill University, 2002 Submitted to the Department of Civil and Environmental Engineering In Partial Fulfillment of the Requirements for the Degree of MASTER OF ENGINEERING in Civil and Environmental Engineering at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY JUNE 2003 ©2003 Georges Tabbal All rights reserved. The author hereby grants to M.I.T. permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole and in part. Signature of Author _______________________________________________________ Department of Civil and Environmental Engineering May 9, 2003 Certified by _____________________________________________________________ Bettina Voelker Thesis Supervisor Associate Professor, Department of Civil and Environmental Engineering Certified by _____________________________________________________________ Susan Murcott Thesis Co-Supervisor Lecturer, Department of Civil and Environmental Engineering Accepted by _____________________________________________________________ Oral Buyukozturk Professor of Civil and Environmental Engineering Chairman Departmental Committee on Graduate Studies TECHNICAL AND SOCIAL EVALUATION OF THREE ARSENIC-REMOVAL TECHOLOGIES IN NEPAL By GEORGES TABBAL Submitted to the Department of Civil and Environmental Engineering on May 9th, 2003 in partial fulfillment of the requirements for the degree of Master of Engineering in Civil and Environmental Engineering. Abstract The Terai region of Nepal suffers from arsenic contamination of its groundwater supplies. For the past three years, the Massachusetts Institute of Technology Nepal Water Project Master of Engineering teams have traveled to Nepal to research the extent of the arsenic contamination and to test various household treatment options to remediate it. In January 2003, the author traveled to Nepal as part of this year(cid:146)s Nepal Water Project to study the viability of three arsenic removal technologies: The Arsenic-Biosand filter, the Three-Kolshi and the Two-Kolshi. This study consists of a technical and social evaluation of these three technologies. All three of the filters work well at the technical level, as they were all found to have very high arsenic-removal rates. Considering that arsenic was discovered in Nepal recently (2001) compared to other regions such as West Bengal (1983) or Bangladesh (1981), this study found that there was a relative high level of arsenic awareness within the affected population. Thesis Supervisor: Bettina Voelker Assistant Professor, Department of Civil and Environmental Engineering Thesis Co-Supervisor: Susan Murcott Lecturer, Department of Civil and Environmental Engineering 2 ACKNOWLEDGEMENTS I would like to thank foremost Susan Murcott, Bettina Voelker and Tommy Ngai, my three thesis advisors. Their advice has been very helpful throughout the project, from the preparation stage to the lengthy report writing process. I also would like to thank all the people I worked with in Nepal: Debi, Umesh, Bhim and Upendra who accompanied me on my daily site visits, Meena who introduced me to the sights and sounds of Butwal and the intricacies of Nepali culture and cuisine, Kalawati for providing guidance throughout my stay in Nepal and finally Sanna who provided me with companionship almost every night after a hard day(cid:146)s work. I am also very grateful to RWSSSP for providing me with all the logistics necessary for my work. Thank you, all. I am deeply and happily in your debt. 3 TABLE OF CONTENTS LIST OF FIGURES 8 LIST OF TABLES 10 1.0 INTRODUCTION 11 1.1 MIT NEPAL WATER PROJECT 11 1.2 MIT ARSENIC PROJECTS 12 1.3 OVERVIEW OF NEPAL 13 1.4 RESEARCH OBJECTIVES 15 2.0 ARSENIC BACKGROUND 16 2.1 ARSENIC CHEMISTRY 16 2.2 ORIGIN OF ARSENIC IN THE ENVIRONMENT 17 2.2.1 ANTHROPOGENIC SOURCES 17 2.2.2 PYRITE OXIDATION HYPOTHESIS 18 2.2.3 OXY-HYDROXIDE REDUCTION HYPOTHESIS 19 2.3 ARSENIC CONTAMINATION IN SOUTH ASIA 19 2.3.1 BANGLADESH 20 2.3.2 WEST BENGAL 22 2.3.3 NEPAL 23 3.0 IMPACTS OF ARSENIC CONTAMINATION 25 3.1 HEALTH IMPACT 25 3.1.1 NON-CANCER HEALTH EFFECTS 25 3.1.2 CANCER HEALTH EFFECTS 26 3.2 SOCIAL IMPACT 26 3.2.1 SOCIAL OSTRACISM 26 4 3.2.2 ARSENICOSIS AND HOUSEHOLD INCOME: THE POOR SUFFER MOST 27 3.2.3 ARSENICOSIS AND GENDER: THE WOMEN SUFFER MOST 29 3.3 ECONOMIC IMPACT 30 3.3.1 HOUSEHOLD LEVEL 30 3.3.2 NATIONAL ECONOMY LEVEL 31 4.0 STUDY DESIGN 33 4.1 OVERALL ARSENIC STUDY IN NEPAL 33 4.2 CURRENT ARSENIC STUDY 38 4.2.1 STUDY OBJECTIVES 38 4.2.2 FIELD SITE 39 5.0 ARSENIC REMOVAL TECHNOLOGIES 42 5.1 THREE-KOLSHI 42 5.2 ARSENIC-BIOSAND FILTER 43 5.3 TWO-KOLSHI 46 6.1 ARSENIC METHODS 48 6.2 PERFORMANCE OF THE THREE ARSENIC FILTERS 50 6.2.1 ARSENIC-BIOSAND FILTER 50 6.2.2 THREE-KOLSHI 52 6.2.3 TWO-KOLSHI 53 6.3 FLOW RATES 54 7.0 CREATION OF SURVEY INSTRUMENT 55 7.1 BACKGROUND RESEARCH 55 7.1.1 KNOWLEDGE, ATTITUDES AND PRACTICES (KAP) SURVEYS 55 7.1.2 RAPID ASSESMENTS SURVEYS 56 7.1.3 M.ENG THESES 57 5 7.1.4 RESEARCH PLAN OF (cid:147)EVALUATION OF CERAMIC MIRCOFILTER IN BOLIVIA(cid:148) 63 7.2 SYNTHESIS OF BACKGROUND RESEARCH 64 7.2.1 QUESTIONNAIRE-BASED SURVEYS 65 7.2.2 INTERVIEW-BASED SURVEYS 66 7.2.3 MIXTURE OF INTERVIEW AND QUESTIONNAIRE-BASED SURVEYS 67 7.3 CREATION OF SURVEY INSTRUMENT 68 7.3.1 ORIGINAL SURVEY INSTRUMENT 69 7.3.2 REVISED SURVEY INSTRUMENT 72 8.0 SURVEY RESULTS 74 8.1 BACKGROUND SECTION 74 8.2 WATER QUALITY 76 8.2.1 WATER COLLECTION PRACTICES 76 8.2.2 ARSENIC AWARENESS 78 8.3 FILTERS 80 8.3.1 FOR ANY FILTER 80 8.3.2 ARSENIC-BIOSAND 83 8.3.3 THREE-KOLSHI 86 8.3.4 TWO-KOLSHI 88 8.3.5 IMPRESSIONS 90 9.0 CONCLUSIONS AND RECOMMENDATIONS 94 9.1.1 CRITIQUE OF RESULTS 94 9.1.2 POTENTIAL REASONS 95 9.2 CONCLUSIONS 96 9.2.1 WATER COLLECTION PRACTICES 96 9.2.2 ARSENIC AWARENESS 97 9.2.3 FILTER AWARENESS 99 9.2.4 SOCIAL ACCEPTABILITY OF EACH TYPE OF FILTER 99 6 9.3 RECOMMENDATIONS 100 9.3.1 GUIDELINES FOR FUTURE STUDIES 100 9.3.2 RECOMMENDATIONS FOR FUTURE PROJECTS 101 APPENDIX I: ORIGINAL SURVEY-SURVEY 1 103 APPENDIX II: REVISED SURVEY- SURVEY 2 108 APPENDIX III: JOURNAL OF DAILY SITE VISITS 112 REFERENCES 114 7 LIST OF FIGURES FIGURE 1: 2002-2003 NEPAL GROUP.................................................................................12 FIGURE 2: MAP OF NEPAL..................................................................................................14 FIGURE 3: EXTENT OF ARSENIC CONTAMINATION IN BANGLADESH (CRISIS INFORMATION CENTER)....................................................................................................................21 FIGURE 4: EXTENT OF ARSENIC CONTAMINATION IN WEST BENGAL (CRISIS INFORMATION CENTER)....................................................................................................................23 FIGURE 5:RELATIONSHIP BETWEEN PREVALENCE OF ARSENICOSIS AND HOUSEHOLD INCOME ...................................................................................................................................29 FIGURE 6: ORGANIZATIONAL CHART OF DRINKING WATER QUALITY IMPROVEMENT PROGRAM..................................................................................................................35 FIGURE 7: MAP OF VISITED DISTRICTS..............................................................................39 FIGURE 8: PICTURE OF TERAI.............................................................................................40 FIGURE 9: THREE-KOLSHI FILTER......................................................................................43 FIGURE 10: SCHEMATIC DIAGRAM OF THE ARSENIC-BIOSAND FILTER (NGAI AND WALEJWICK, 2003)....................................................................................................45 FIGURE 11: ARSENIC-BIOSAND FILTER IN THE BACKYARD OF A HOUSE IN SARAWAL........46 FIGURE 12: TWO-KOLSHI FILTER IN SUNWAL....................................................................47 FIGURE 13: NUMBER AND PERCENTAGE OF HOUSEHOLDS SURVEYED FOR EACH TYPE OF FILTER........................................................................................................................75 FIGURE 14: DISTRIBUTION OF SURVEYS PER GENDER.........................................................75 FIGURE 15: HOW MANY PEOPLE ARE THERE IN YOUR HOUSEHOLD?(54 RESPONDENTS).....76 FIGURE 16: HOW FAR FROM YOUR HOUSEHOLD IS YOUR MAIN SOURCE OF DRINKING WATER? (47 RESPONDENTS).......................................................................................77 FIGURE 17: WHO COLLECTS THE WATER FOR YOUR HOUSEHOLD? (54 RESPONDENTS).......77 FIGURE 18: DO YOU KNOW WHAT ARSENIC IS? (54 RESPONDENTS)....................................78 FIGURE 19: WHAT IS ARSENIC? (45 RESPONDENTS)...........................................................78 FIGURE 20: ARE YOU AWARE OF ANY ARSENIC CONTAMINATION IN YOUR WATER? (54 RESPONDENTS)...........................................................................................................79 8 FIGURE 21: DO YOU SEE ANY CORRELATION BETWEEN REMOVING ARSENIC AND PROTECTING YOUR HEALTH? (54 RESPONDENTS).......................................................80 FIGURE 22: WHO CLEANS THE FILTER IN YOUR HOUSEHOLD? (53 RESPONDENTS)..............81 FIGURE 23: WHY DO YOU TREAT THE WATER? (52 RESPONDENTS)....................................82 FIGURE 24: DO YOU THINK THE FILTER IS PROTECTING YOUR HEALTH? (54 RESPONDENTS) ...................................................................................................................................83 FIGURE 25: ARE YOU SATISFIED WITH THE FLOW RATE OF THE FILTER? (14 RESPONDENTS) ...................................................................................................................................83 FIGURE 26: ARE YOU SATISFIED WITH THE FLOW RATE OF THE FILTER (12 RESPONDENTS)? ...................................................................................................................................84 FIGURE 27: DO YOU THINK THAT OPERATING THE FILTER REQUIRES TOO MUCH WORK (13 RESPONDENTS)?.........................................................................................................85 FIGURE 28: HOW OFTEN DO YOU SKIP FILTRATION (12 RESPONDENTS)?............................85 FIGURE 29: ARE YOU SATISFIED WITH THE FLOW RATE OF THE FILTER (16 RESPONDENTS)? ...................................................................................................................................86 FIGURE 30: HOW OFTEN DO YOU SKIP FILTRATION (16 RESPONDENTS)?............................87 FIGURE 31: DO YOU THINK THAT OPERATING THE FILTER REQUIRES TOO MUCH WORK (16 RESPONDENTS)?.........................................................................................................88 FIGURE 32: ARE YOU SATISFIED WITH THE FLOW RATE OF THE FILTER (19 RESPONDENTS)? ...................................................................................................................................88 FIGURE 33: HOW OFTEN DO YOU SKIP FILTRATION (19 RESPONDENTS)?............................89 FIGURE 34: DO YOU THINK THAT OPERATING THE FILTER REQUIRES TOO MUCH WORK (18 RESPONDENTS)?.........................................................................................................90 9 LIST OF TABLES TABLE 1: RESULT OF ENPHO(cid:146)S TESTING AS OF AUGUST 2001..........................................37 TABLE 2: RESULTS OF ARSENIC-BIOSAND FROM TOMMY NGAI AND SOPHIE WALEWIJK..51 TABLE 3: ARSENIC RESULTS OF ARSENIC-BIOSAND FROM GEORGES TABBAL..................51 TABLE 4: ARSENIC RESULTS OF ARSENIC-BIOSAND FROM RWSSSP................................52 TABLE 5: ARSENIC RESULTS OF THREE-KOLSHI FROM GEORGES TABBAL........................52 TABLE 6: ARSENIC RESULTS OF THREE-KOLSHI FROM RWSSSP......................................53 TABLE 7: ARSENIC RESULTS OF TWO-KOLSHI FROM ENPHO...........................................53 TABLE 8: FLOW RATES OF FILTERS....................................................................................54 TABLE 9: GEOGRAPHICAL DISTRIBUTION OF SURVEYS......................................................74 TABLE 10: COMPARISON OF THE RESULTS OF THE THREE FILTERS.....................................94 10