Nepal Water Project - MITweb.mit.edu/watsan/Docs/Student Reports/Nepal/NepalGroupReport2002.pdf ·...

Massachusetts Institute of Technology Department of Civil and Environmental Engineering

Masters of Engineering Program

Nepal Water Project 2001-2002

Team Advisor:

Susan Murcott

Team Members:

Yong Xuan Gao Soon Kyu Hwang

Chian Siong Low Heather Lukacs

Luca Morganti Tommy Ngai

Barika Poole Hannah Sullivan

May 28, 2002

Nepal Water Project Group Report 2002

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ABSTRACT The work accomplished in the 2001-2002 Massachusetts Institute of Technology Nepal Water Project can be categorized into four project phases � methodological evaluation in tropical and developing countries, site investigation, technology evaluation, and implementation. In terms of methodological evaluation in tropical and developing countries, for enumeration of indicators organisms using the membrane filtration procedure, E.coli is the proposed indicator of routine water quality monitoring. However, if E.coli is in small concentrations, fecal coliform is the next most appropriate indicator to use. Based on the criteria: cost, ease of preparation, ease of interpretation, the following culture media were determined to be the most preferred for use in tropical and developing countries: for E.coli, either EC with MUG or m-ColiBlue24, for fecal coliform, m-FC with rosalic acid, for total coliform, m-ColiBlue24. For the evaluation of microbial removal in filters, the enumeration of fecal coliform by membrane filtration is the proposed indicator test in the work of the MIT Nepal Water Project. A further aspect of the methodological evaluation involved the determination that the hydrogen sulfide (H2S) producing bacteria Presence/Absence test could give the same degree of accuracy when samples were held for up to 72 hours, without incubation under ambient temperatures which ranged from 5 to 30 degrees C, as H2S samples incubated at the specified 35 degrees C over a 24 to 48 hour period. In the site investigation phase, H2S-producing bacteria contamination was found to be linked to the use of cow dung in well construction, as 42% of 208 tubewells tested in Butwal and the surrounding areas were contaminated with H2S-producing bacteria. On the arsenic contamination side, the Rural Water Supply and Sanitation Support Program (RWSSSP) found that 9.8% of 1,508 samples collected and analyzed since 2001 in the Districts of Rupandehi, Nawalparasi, and Palpa have over 10 mg/L of arsenic, the WHO standard. The MIT Nepal Water Project Tean found that arsenic (III) accounts for 79% of total arsenic in 37 wells in Rupandehi and Nawalparasi Districts. In the technology evaluation phase, ceramic disk filters, on average, removed 94% total coliform and 85% turbidity. For arsenic remediation, three technologies, activated alumina manganese oxide (A/M), iron-coated sand, and the ENPHO Arsenic Removal System, were evaluated. The average arsenic removal rate for these technologies were 97%, 55%, and 89% respectively. In the implementation stage, the Lumbini Chlorination Pilot study and the Lumbini Biosand Pilot studies were found to be successful. The development of a micro-enterprise involved in sodium hypochlorite on-site generation for household water disinfection was also initiated.


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ACKNOWLEDGEMENTS The team would like to thank the following people and groups. Without their generous help and support, the 2001-2002 MIT Nepal Water Project would not be possible.

• Susan E. Murcott, MIT • Dr. Eric Adams, MIT • Amy Smith, MIT • The Ralph Parsons Laboratory, MIT • Department of Material Science, MIT • Environment and Public Health Organization (ENPHO) • Hari Govinda, Madhyapur Clay Crafts • Jim Brannen (Severn Trent De Nora) • Department of International Cooperation (DIDC), formerly the Finnish International

Development Agency (FINNIDA) • International Buddhist Society (IBS)


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TABLE OF CONTENTS

1. INTRODUCTION....................................................................................................................... 7

2. OBJECTIVES AND SCOPE OF THE PROJECT............................................................................. 8

3. METHODOLOGY.................................................................................................................... 10 3.1 APPROPRIATE MICROBIAL INDICATORS AND TESTS ........................................................ 10 3.2 CHLORINE TESTS............................................................................................................ 11 3.3 ARSENIC TESTS .............................................................................................................. 11

4. RESULTS & DISCUSSION ....................................................................................................... 12 4.1 METHODOLOGICAL EVALUATION IN TROPICAL AND DEVELOPING COUNTRIES ............. 12

4.1.1 Culture media selected for membrane filtration....................................................... 12 4.1.2 Hydrogen Sulfide Producing Bacteria Presence Absence Test Method................... 13

4.2 SITE INVESTIGATIONS .................................................................................................... 13 4.2.1 The Lumbini tubewell survey .................................................................................... 13 4.2.2 The RWSSSP tubewell program................................................................................ 15 4.2.3 Arsenic survey........................................................................................................... 18

4.3 POU WATER TREATMENT TECHNOLOGIES...................................................................... 21 4.3.1 Ceramic filters .......................................................................................................... 21 4.3.2 Biosand filter............................................................................................................. 24 4.3.3 Arsenic removal technologies ................................................................................... 25

4.4 IMPLEMENTATION PROGRAMS........................................................................................ 32 4.4.1 Sodium hypochlorite generation in Kathmandu ....................................................... 32 4.4.2 Lumbini pilot studies................................................................................................. 36

5. CONCLUSIONS....................................................................................................................... 40

6. APPENDIX.............................................................................................................................. 43

7. REFERENCES......................................................................................................................... 45


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LIST OF TABLES Table 2-1 � Summary of past and present work ............................................................................. 9 Table 4-1 � Summary of MF culture media used for different indicator organisms. ................... 12 Table 4-2 � Correlation between IDRC H2S P/A tests and fecal coliform MF tests .................... 13 Table 4-3 � Fecal coliform contamination in public tubewells .................................................... 14 Table 4-4 � Use of cow dung in construction ............................................................................... 17 Table 4-5 � Proportions of ingredients used in the first set of prototypes fired at 1000°C. ......... 22 Table 4-6 � Performance summary of TERAFIL and Thimi ceramic filters. .............................. 23 Table 4-7 � Summary arsenic results on A/M and BP/I3 & A/M systems ................................... 26 Table 4-8 � Summary of produced iron oxide coated sands (IOCS)............................................ 28 Table 4-9 � Summary of field test results..................................................................................... 29 Table 4-10 � Arsenic removal results for Parasi........................................................................... 31 Table 4-11 � Comparison between different technologies for arsenic removal ........................... 32 LIST OF FIGURES Figure 1.1 � Nepal and Asia ........................................................................................................... 7 Figure 4.1 � A suction tubewell.................................................................................................... 15 Figure 4.2 � Contamination vs. use of cow dung ......................................................................... 17 Figure 4.3 � Total arsenic concentrations for 37 wells in various villages................................... 19 Figure 4.4 � Arsenic (III) as % of total arsenic for the 37 wells in various villages. ................... 19 Figure 4.5 � Correlation between % arsenic (III) and ORP.......................................................... 21 Figure 4.6 � TERAFIL filter tested in MIT .................................................................................. 23 Figure 4.7 � TERAFIL ceramic filter disk.................................................................................... 23 Figure 4.8 � IOCS 4-7 in lab at MIT ............................................................................................ 28 Figure 4.9 � ENPHO Arsenic Removal System (ARS)................................................................ 30 Figure 4.10 � The SANILEC-6 sodium hypochlorite generator................................................... 34 LIST OF ABBREVIATIONS ARS ENPHO Arsenic Removal System CFU Colony Forming Unit DIDC Department of International Development Co-operation DPD N,N-diethyl-p-phenylenediamine ENPHO Environment and Public Health Organization FC Fecal coliform FEAS Ferrous Ethylenediammonium Sulfate FINNIDA Finnish International Development Agency GFAAS Graphite Furnace Atomic Adsorption Spectrometry H2S Hydrogen Sulfide IDRC International Development Research Centre, Ottawa, Canada IRs Indian Rupees (US$ 1 = IRs 43 in January 2002) LT/BCP Lauryl Tryptose with Bromocresol Purple Indicator MF Membrane Filtration


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MUG 4-methyl-umbelliferyl-β-D-glucuronide NGO Non-Government Organization NRs Nepali Rupees (US$ 1 = NRs 75 in January 2002) NTU Nephelometric Turbidity Unit ORP Oxidation-Reduction Potential P/A Presence-Absence RWSSSP Rural Water Supply and Sanitation Support Program SMEWW Standard Method for the Examination of Water and Wastewater TC Total Coliform VMW Village Maintenance Workers


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1. Introduction The Massachusetts Institute of Technology (MIT) Nepal Water Project is a program intended to increase the awareness of water quality problems in the country of Nepal, and to provide assistance in solving these problems. Since 1999, twenty Master of Engineering students from the MIT Civil and Environmental Engineering Department have traveled to Nepal to study water quality and household water treatment issues. This year�s project (2001-2002) is a collective effort of eight students: Heather Lukas, Chian Siong Low, Hannah Sullivan, Yong Xuan Gao, Luca Morganti, Barika Poole, Soon Kyu Hwang, and Tommy Ngai. Nepal is a developing country in south central Asia landlocked between China to the north and India to the south. The land area is 140 000 km2 and the year 2000 population is 23 million, of which 20 million are is rural1. Nepal is one of the world�s poorest and least developed countries. The average annual per capita income is $210 US.2 About 42% of the people live below the national poverty line.3 Due to the poor economic conditions and ineffective institutional programs, proper water and sanitation services are inadequate, resulting in serious health concerns. The severity of the water crisis is even more prominent in the rural villages. The infant mortality rate is high at 74/1000 live births, compared with 5/1000 in the U.S. The under-five mortality is even higher at 105/1000 births.4 Fifty four percent of the population suffers moderate to severe stunting5. Diarrheal diseases kill 44,000 children annually. The average life expectancy is only 58, compared with 77 in the U.S.6 Their serious health condition due to waterborne diseases is the main motivation for this project.

Figure 1.1 – Nepal and Asia


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2. Objectives and scope of the project

The objective of the MIT Nepal Water Project is to improve the health situation in Nepal through improvements in drinking water quality. This objective is accomplished by continuation and expansion of the work done in the two previous academic years, specifically in pathogens and arsenic contamination issues. Pathogens, which are disease-causing microorganisms, are of 4 main classes: bacteria, viruses, protozoa, and helminths. Microbial contamination is the leading cause of waterborne diseases, including diarrhea, intestinal worms, trachoma, schistosomiasis, cholera, amebiasis, giardiasis, stunting and other diseases.7 Humans are typically the main carriers of large populations of these pathogens.8 At any given time, about half of the population in developing countries, including Nepal, is suffering from these diseases.9 Drinking water is the main route of transmission for pathogens of fecal origin. Unhygienic practices during the handling of food, utensils and clothing also play an important role in making these diseases endemic in developing countries. Arsenic has been long known as a poison. Exposure to arsenic via drinking water initially causes skin diseases such as pigmentation (dark and light spots on the skin) and arsenicosis (hardening of skin on hands and feet). Later, cancer of the skin, lungs, bladder, and kidney may occur.10 Unfortunately, there is no cure for these diseases. Both the World Health Organization (WHO) and the U.S. Environmental Protection Agency (USEPA) have classified arsenic as a carcinogen and have set the maximum contaminant level at 10 µg/L. The Nepali standard is currently set at 50 µg/L for drinking water. The MIT Nepal Water Project work accomplished to date can be categorized into four project phases � � methodological evaluation in tropical and developing countries, site investigation, technology evaluation, and implementation. Chian Siong Low, Hannah Sullivan and Xuan Yong Gao researched different aspects of methodologies for tropical and developing countries, specifically in terms of coliform culture broth applicability and hydrogen sulfide (H2S) producing bacteria presence/absence (P/A) testing at ambient temperature. For this year, in the site investigation phase, H2S bacteria contamination in tubewells has been studied by Yong Xuan Gao as part of her work on a tubewell program. Heather Lukacs and Hannah Sullivan also surveyed wells on H2S bacteria and fecal coliform contamination as part of their Lumbini pilot study. Barika Poole assembled the data set of known arsenic contaminated tubewells. Tommy Ngai conducted total arsenic and arsenic speciation tests at 37 wells with known arsenic contamination. In the technology evaluation phase, Chian Siong Low assessed ceramic disk filters for removal of microbial contamination. He also compared and recommended appropriate microbial indicator tests for drinking water in developing countries. For arsenic remediation, Tommy Ngai, Barika Poole, and Soon Kyu Hwang evaluated three technologies: activated alumina manganese oxide (A/M), iron-coated sand, and ENPHO ARS, respectively. In the implementation stage, Heather Lukacs and Hannah Sullivan assessed the effectiveness of a biosand pilot study and a household water chlorination program. Luca Morganti identified conditions for and started the development of a micro-enterprise involved in sodium hypochlorite on-site generation for household water disinfection. Refer to Table 2-1 for a summary of past and present work.


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Table 2-1 – Summary of past and present work

Project Phases 1999-2000 2000-2001 2001-2002 1. Methodological Evaluation

• Affiniti concentration field kits with E.M. Quant® to attain a 10µg/L arsenic detection limit.

• Arsenic field investigation using the industrial Test Systems ArsenicCheckTM test kit

• Self-prepared IDRC-H2S tests

• Evaluation of appropriate microbial indicators and their test techniques

• Self-prepared IDRC-H2S tests

• Field test of phase-change field incubator

2. Site Investigation

• Microbial (H2S, TC, E.Coli with P/A tests)

• Arsenic (Total) • Nitrate &

Ammonia

• Microbial (H2S, TC, E.Coli with P/A tests)

• Microbial under lab conditions (H2S P/A, TC, FC, E.Coli with MF tests)

• Microbial under field conditions (H2S P/A, TC, FC, E.Coli with MF tests)

• Arsenic (Total and Speciation of As (III) and As (V))

3. Technology Evaluation

• Coagulation (with Alum)

• Filtration (Indian candle filter, Nepal candle filter, Gift of Water Inc. filter)

• Disinfection (SODIS, chlorine)

• Filtration (Biosand, CerCor)

• Disinfection (SODIS)

• Arsenic (3-G, Jerry Can, ATU)

• Filtration (Ceramic disk filters, Biosand)

• Arsenic (A/M & BP/I3, Iron-coated sand, ENPHO ARS)

4. Implementation Programs

• Biosand pilot study

• Lumbini pilot studies (Biosand, Chlorination)

• Tubewell program • Hypochlorite

generation micro-enterprise


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3. Methodology 3.1 Appropriate microbial indicators and tests One approach to monitoring drinking water for pathogens is direct detection of the pathogen itself. However, it would be practically impossible to test for each of the wide variety of pathogens that may be present in polluted water. Furthermore, these methods are often difficult, relatively expensive, and time-consuming. Instead, water monitoring for microbiological quality is primarily based on a second approach, which is to test for indicator organisms. The rationale for using indicator organisms can be crudely illustrated below:

[indicator organism] α fecal contamination α [pathogen] ≡ disease occurrence

This shows the indirect relationship between the concentration of indicator organisms and pathogen population. It has been established that when a certain population of pathogens is present in humans, they can cause diseases. Therefore, when indicator organisms are present, that would indicate the likely presence of pathogens too. The indicator organism should fulfill the following criteria:11

1) An indicator should always be present when pathogens are present; 2) Indicators and pathogens should have similar persistence and growth characteristics; 3) Indicators and pathogens should occur in a constant ratio so that counts of the indicators

give a good estimate of the numbers of pathogens present; 4) Tests for the indicator should be easy to carry out and applicable to all types of water; 5) The test should detect only the indicator organisms thus not giving false-positive

reactions. Another reason for using simple indicator tests is that pollution is often intermittent and/or undetectable. It is better to examine drinking water frequently by means of a simple test than to monitor infrequently using a longer and more complicated direct pathogen detection test. The 4 main groups of indicator organisms that together formed the basis for our evaluation of microbial contamination are total coliforms, thermotolerant coliforms, E.coli, and H2S-producing bacteria. Coliforms have traditionally been used as indicators based on the assumption that there is a quantifiable relationship between the concentration of coliform indicators and the potential health risks involved. Another major reason coliform has been used is because they are easy to detect and enumerate in water. However, with recent advances in recovery techniques, coliforms are increasingly recovered from non-fecally contaminated environments in both temperate and tropical climates. Studies have shown that coliform presence are not necessarily indicative of pathogens and hence health threat.12 Coliforms have been found to be capable of re-growth in distribution systems and even in chlorinated sewage.13 Finally, the definition of the coliform group is not precise and a significant number of false positive and negative results can arise from


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the total coliform tests.14,15 Therefore, it is questionable to use total coliforms as indicators of recent fecal contamination and thus drinking water quality. E.coli, on the other hand, is considered a better indicator of recent fecal contamination. E.coli is assumed exclusively fecal in origin because it consists of up to 95% of the Enterobacteriaceae found in feces.16 H2S-producing bacteria presence has also been found to correlate with coliform and E.coli presence17. Therefore, the presence of H2S-producing bacteria in drinking water is also being monitored to indicate fecal contamination. Two main types of microbial test methodologies were used: Presence-Absence (P/A) and Membrane Filtration (MF). The HACH PathoScreen P/A test for 20 ml sample was used to detect H2S-producing bacteria as an easy alternative test for coliforms. The lab-made H2S paper strip test promoted by IDRC was also used in the field. The HACH LT/BCP with MUG P/A test for 100 ml sample was used to detect total coliforms and E.coli. The team used the portable Millipore MF stainless steel filter holder for enumeration using the MF technique. MF for FC or E.coli is recommended for routine water quality monitoring if enumeration is required. m-FC or EC with MUG medium were determined as preferred tests for fecal coliform and E.coli enumeration with MF. If total coliform enumeration is desired, m-ColiBlue24 medium is recommended. The fecal coliform and E.coli (except when m-ColiBlue24 is used) samples were incubated at 44.5±0.2°C with the Millipore incubator. The total coliform samples were incubated at 35±0.5°C with either a Millipore incubator or phase-change field incubator.

3.2 Chlorine tests

Available chlorine concentration in freshly produced sodium hypochlorite solutions was measured in Kathmandu using HACH Method 8209 (Iodometric Method Using Digital Titrator). This method is equivalent in principle to the Iodometric Method I described in Standard Methods for the Examination of Water and Wastewater (1998) (SMEWW). HACH Method 10069 (DPD with spectrophotometer) was used to measure free residual chlorine in tap water samples taken from the Kathmandu public supply system and disinfected with freshly made sodium hypochlorite (range of free chlorine 0-5 mg/L). This method is adapted from the DPD colorimetric Method in SMEWW. In contrast, water samples from households in Lumbini were tested for free residual chlorine with HACH Method 8210 (DPD and Digital Titrator-FEAS).

3.3 Arsenic tests

Total inorganic arsenic in the field sites of Nepal was first measured with an Industrial Test Systems, Inc. Arsenic CheckTM Field Test Kit, and confirmed with a Graphite Furnace Atomic Adsorption Spectrometry (GFAAS). GFAAS is one of the USEPA methods for measuring arsenic in drinking water. For the arsenic speciation test, the sample was first treated with Bio-Rad Laboratory�s AG1-X8 ion exchange resin, 100-200 mesh, acetate form. This strong ion exchange resin adsorbs all arsenic (V), leaving only arsenic (III) in the sample water. By comparing the arsenic (III) concentration in the sample with total arsenic, the concentration of arsenic (V) can be determined by a simple subtraction.


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4. Results & discussion 4.1 Methodological Evaluation in Tropical and Developing Countries

4.1.1 Culture media selected for membrane filtration

Several MF culture media were evaluated in the laboratory and compared in terms of 3 criteria: cost, ease of preparation, and ease of result interpretation. Table 4-1 summarizes the results:

Table 4-1 – Summary of MF culture media used for different indicator organisms. Company Preparation Colony Color Cost1 Per

Sample Ease of Preparation

Ease of Interpretation

Medium for E.coli

m-ColiBlue24 HACH Pre-packed TC � Red E.coli � Blue

US$1.50 Easy-None Easy

EC with MUG VWR Self-prepared Cream, fluoresce under UV

US$0.060 Medium Easy

Medium for Fecal Coliform

m-FC with rosalic acid

HACH Pre-packed Dark Blue US$0.83 Easy-None Easy

m-FC with rosalic acid

HACH Self-prepared Dark Blue US$0.013-US$0.028

Medium Easy

EC VWR Self-prepared Cream US$0.017 Medium Medium Medium for Total Coliform

m-Endo HACH Pre-packed Dark red with metallic sheen

US$0.74 Easy-None Difficult

m-ColiBlue24 HACH Pre-packed TC � Red E.coli � Blue

US$1.50 Easy-None Easy

Chromocult VWR Self-prepared TC � Salmon to Red E.coli � Dark Blue to Violet

US$0.85-US$1.30

Medium Medium

1Costs do not include petri dish and membrane filter paper. For the enumeration of E.coli, either EC with MUG or m-ColiBlue24 fit the criteria because the E.coli colonies show up distinctly. For fecal coliform, m-FC with rosalic acid medium (self-prepared) was the best because of its low cost and ease of colony interpretation. If total coliform is desired, the m-ColiBlue24 medium (pre-packed) was selected for its ease of colony identification.


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4.1.2 Hydrogen Sulfide Producing Bacteria Presence Absence Test Method Tests conducted in Butwal and in Lumbini led the researchers Yong Xuan Gao and Hannah Sullivan to the determination that the hydrogen sulfide (H2S) producing bacteria Presence/Absence test could give the same degree of accuracy when held for up to 72 hours, without incubation under ambient temperatures which ranged from 5 to 30 °C, as H2S samples incubated at the proper 35 °C over a 24 to 48 hour period.

In another investigation, 67 tubewells were tested for both P/A H2S bacteria (10 ml IDRC method) and fecal coliform using membrane filtration. Correlation results in Table 4-2 demonstrate that H2S tests are valuable for ruling out high-level (>15 cfu/100ml) contamination. Correlation is perfect at >15 CFU/100 mL and, at 0.82, is fairly good but not perfect at 0 CFU/100 mL. Correlation between 0 and 15 CFU/100 mL ranged from fair to moderate. A drawback of the H2S P/A analysis was its inability to distinguish between clean wells and those minimally contaminated and to separate mid-level contamination (20 CFU/100ml) from high-level contamination (>200 CFU/100ml).

Table 4-2 – Correlation between IDRC H2S P/A tests and fecal coliform MF tests

Level of Fecal Coliform Contamination Correlation All levels 0.57 0 CFU / 100ml 0.82 1-4 CFU / 100 ml 0.54 >5 CFU / 100ml 0.88 >15 CFU / 100ml 1.0

4.2 Site investigations 4.2.1 The Lumbini tubewell survey Between January 8, 2002 and January 20, 2002 a well survey was conducted in Lumbini to evaluate the prevalence of microbial contamination in this region of Nepal as well as to observe the water handling and storage practices of Lumbini villagers. The January 2002 well survey represents the most rigorous survey of tubewell water quality conducted in Lumbini to date. During the two weeks of the well survey, all 17 villages currently served by IBS were visited and all IBS installed wells, as well as several privately installed and operated wells, were tested for bacterial contamination using both H2S P/A tests and fecal coliform enumeration tests. This water quality analysis was accompanied by a preliminary sanitary survey designed to identify potential sources of tubewell contamination and waterborne disease in Lumbini.


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Overall 40 public tubewells were tested for fecal coliform bacteria in Lumbini*. These included wells installed by IBS and other aid organizations and were between 74 and 350 feet in depth. The majority of these wells were installed between 1997 and 2002, and villagers have been instructed to obtain their drinking water from these sources. Fecal coliform bacteria were detected in 12 wells, or 33 percent of the public wells sampled. Wells that were installed just prior to sampling showed extremely elevated levels of fecal contamination sometimes on the order of 10,000 CFU per 100ml. These elevated levels of contamination are due to the use of cow dung slurry in well construction and are not indicative of long-term contamination. The highest level of contamination found in wells older than one month was 14 CFU/100 ml, indicating that contamination from the use of cow dung slurry does not persist in tubewell water longer that one month after well construction is completed. Eliminating the 4 wells that were constructed in the month immediately prior to sampling, fecal coliform bacteria were found in only 22 percent of public tubewells in Lumbini. Furthermore, the concentrations of fecal coliform bacteria detected ranged from 2 to 14 CFU per 100 ml (detection limit of 2 CFU/100ml), with an average concentration of less than 1.2 CFU/100 ml among all public wells.

Table 4-3 – Fecal coliform contamination in public tubewells

Age of Well Number of Wells Percent Contaminated Average Contamination < 1 month 4 100% > 500 CFU per 100 ml > 1 month 36 22% < 5 CFU per 100 ml

Bacterial contamination in rural water supplies at the levels detected during this well survey in Lumbini is not necessarily a cause of concern. As one researcher with significant experience in developing countries states, �Untreated water sources almost always contains some fecal coliform bacteria; the question is, does a particular source contain more than the alternative sources available? To apply the WHO standard for disinfected water would be to condemn the water supplies used by most rural people in developing countries.�18 In fact in recent years, there have been suggestions to adapt the WHO guidelines for use in developing countries. The WHO is now acknowledging the relevance of �medium-term� targets aimed at progressive improvements in water quality, recognizing that �in the great majority of rural water supplies in developing countries, fecal contamination is widespread and achieving the guideline values for E.coli or fecal coliforms is often not possible.�19 Based on the well survey results obtained in January 2002 and the considerations discussed above, there does not appear to be a significant bacterial contamination problem in the IBS tubewells in Lumbini*. These results should not be viewed as conclusive for two reasons. One, potentially significant complications were encountered with the use of membrane filtration techniques in the field in Nepal, as discussed above. And two, this well survey was conducted

* One public open well was also tested in Lumbini and was found to have E.Coli and fecal coliform levels of over 300 CFU/100 ml. This well was not included in the public well statistics because the open wells in Lumbini are widely understood to be contaminated and villagers have been instructed to use the IBS tubewell near this open well for their drinking water. * This considers only the membrane filtration tests for fecal coliform bacteria because fecal coliform, as well as E. Coli are the standard indicator organisms used by the World Health Organization to set microbial water quality standards.


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during the dry season in Lumbini and an additional well survey must be completed during the monsoon season, between June and September, to confirm these results and determine if bacterial contamination levels increase significantly in Lumbini during this period. Follow-up surveys should be completed in Lumbini to confirm the finding presented here, fine-tune the use of membrane filtration in the field in Nepal, and develop microbial data for the rainy season in Lumbini. If these follow-up studies reveal similar low levels of microbial contamination in public tubewells during the monsoon season it will be important to investigate other potential causes of the waterborne disease so prevalent in Lumbini. Several possible causes for the prevalence of waterborne disease in Lumbini should be examined, including:

! The use of private tubewells, open wells, and open water sources for drinking water ! Improper household water storage leading to bacterial contamination ! Lack of sanitation facilities, including latrines and washing platforms ! Limited awareness about basic hygiene practices such as hand washing

4.2.2 The RWSSSP tubewell program A decentralized, community-based tubewell program is one answer to the water crisis in the Terai region of Nepal, which is endowed with groundwater resources as the primary drinking water supply. One tubewell program, part of the Rural Water Supply and Sanitation Support Program (RWSSSP) implemented by the DIDC (formerly known as FINNIDA) in Lumbini Zone, has successfully provided people with accessible and potable water for the past 10 years.20 Tubewells, which are wells fitted with a handpump and surrounded by a platform at the base and connected to a drainage channel, are widely used in Terai (Figure 4.1). However, several NGOs, including DIDC, have found that some tubewells are contaminated with bacteria whose presence indicates possible contamination with pathogens of fecal origin.

Figure 4.1 – A suction tubewell

H2S bacteria presence/absence (P/A) tests were used for microbial testing of tubewell water in the area around the village of Butwal. Water samples were left in 20-ml bottles that had H2S


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bacteria broth in them for 48 to 72 hours at room temperature (22-30°C for H2S tests conducted in Butwal and 5-25°C for H2S tests conducted in Lumbini). The water would turn black if it tested positive; otherwise the color would not change. Untrained personnel can reliably use this method, which has the advantages listed below:21 1. It requires simple ingredients (listed in the Appendix) that are readily available in Nepal (the

broth can be �self-prepared�). 2. The growth medium is in the form of a dried paper strip, which can be safely stored at room

temperature for at least 6 months. 3. The black positive reaction is easy to read. 4. The test can be carried out at ambient temperature in the Terai region of Nepal, where

minimum temperature is about 10 degrees C, without the use of an incubator or other special laboratory equipment.

Another set of samples was put in a phase-change incubator, invented by Amy Smith at MIT, and was used to determine if incubation was necessary in the Terai Region for H2S P/A test. It is found that generally, incubation would make the sample turn back within 24 hours if the well was contaminated. However, without incubation, the sample would still turn back in 48 hours if the well were contaminated. Therefore, incubation was not deemed necessary, because the contaminated sample would still turn black given a long enough reaction time at ambient temperature. During three weeks of fieldwork, team member Yong Xuan Gao collected an H2S test data set representing 163 wells and out of which, she herself tested 45 wells. Forty-two percent of the samples tested positive for H2S bacteria. This result agrees with other NGOs� findings. Six factors, which might be causes for the contamination, were identified, including:

1. Number of users per well; 2. Depth of the wells; 3. Age of the wells; 4. Distance to the nearby latrine; 5. Distance to the nearby animal shed; 6. Use of cow dung as slurry in the construction of tubewells. Based on analysis of the data, it is found that the first five factors do not have any significant relationship with the microbial contamination, i.e., they are unlikely to cause the contamination. The use of cow dung in the construction process, however, was found to make significant contribution to the contamination problem. Table 4-4 shows the numbers of tubewells that were constructed with and without cow dung. It also shows how many of these wells were contaminated with H2S bacteria. The result is also shown graphically in Figure 4.2. As seen from the figure, there is an increase of the percentage of contaminated wells from �without cow dung� to �with cow dung� (17.8% of increase).


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Table 4-4 – Use of cow dung in construction

Number of Wells Not Contaminated 17 Without Cow

Dung Contaminated 11 Not Contaminated 58 With Cow Dung Contaminated 77

Using cow dung is a traditional way of building a well, although DIDC has recently stopped using cow dung and uses bentonite instead in building new tubewells. The concern here is not primarily the fecal coliforms in the cow dung, because it is found that all the fecal coliforms in the cow dung would die out in 9 months after construction (Lukacs, 2002). Hence, this will not affect the microbial quality of the well water in the long term. However, the main problem is that cow dung is mainly organic matter, which will disintegrate over time. Wells may have cracks and holes around the PVC pipe underneath the platform. The spacing can store dirty water, which in turn may seep into the tubewell, breeding an environment that leads to microbial contamination. Field observation and literature review also suggest that the contamination may be introduced by floodwater during monsoon, priming of the well with dirty external water, free access of animals to the wells and other unsanitary practices.

Figure 4.2 – Contamination vs. use of cow dung


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Due to the above-mentioned problems, measures are needed to eliminate and prevent contamination. A maintenance program might ensure the proper operation of the tubewells. In principle, DIDC has a good tubewell scheme, which is described in various studies.20,22 This scheme includes the training of tubewell mechanics, creation of a users� committee system and encouragement of women�s participation. Although the principles of this scheme are excellent, in reality good ideas are ignored. Therefore, the following actions are recommended for RWSSSP:

• Continue to monitor well water quality. H2S bacteria presence/absence test should be performed bi-annually to monitor water quality of the well.

• Evaluate the tubewell program yearly to ensure that the program principles are enforced. • Make village maintenance workers (VMW) paid positions, so that VMWs will have more

initiative to take responsibility and perform their job properly. • Clean the platform and the drainage channel. Algae can grow on the platform. Trash can

accumulate on the platform and the channel, therefore, cleaning the platform and the channel regularly is important to ensure that dirty water will not percolate into the well.

• Improve the health and hygiene education program. New or improved education programs should be implemented in the rural area to teach people about the importance of handling and storing water safely, and personal hygiene. Health education motivators should be hired by the RWSSSP program to inform people about the importance of sanitary practices and teach villagers how to handle water safely.

• Use household level chlorination or biosand filtration. • Conduct sanitary surveys.

4.2.3 Arsenic survey

Team member Tommy Ngai visited 37 tubewells throughout the Nawalparasi and Rupandhi Districts, which, according to RWSSSP records, contained total arsenic of over 50 µg/L. RWSSSP found that 9.8% of 1,508 samples collected and analyzed since 2001 in the Districts of Rupandehi, Nawalparasi, and Palpa have over 10 mg/L of arsenic, the WHO standard. In addition, Ngai performed arsenic speciation tests at the 37 tubewells he sampled. For each of these wells, the total arsenic, arsenic (III), pH, and ORP of the raw water was measured. Results for total arsenic and speciation for 37 wells are summarized in Figure 4.3 and Figure 4.4. The highest concentration was 863 µg/L in Bir Bahadur Gurung�s well. The range of arsenic (III) as % of total arsenic was from 40% to 100% with a mean of 79%. Each bar represents one well.


19

0100200300400500600700800900

1000

Madan

gram

Kirtipu

r-1

Kirtipu

r-2

Mukhiy

a tol

Banga

li

Sunwal

Khaka

ribari

Assam

wasi

Khaire

ni

Bisasa

ya

Chaura

ha

Name of Village

Tota

l Ars

enic

( µg/

L)

Figure 4.3 – Total arsenic concentrations for 37 wells in various villages.

0102030405060708090

100

Madan

gram

Kirtipu

r-1

Kirtipu

r-2

Mukhiy

a tol

Banga

li

Sunwal

Khaka

ribari

Assam

wasi

Khaire

ni

Bisasa

ya

Chaura

ha

Village

Ars

enic

(III)

as

% o

f Tot

al A

rsen

ic

Figure 4.4 – Arsenic (III) as % of total arsenic for the 37 wells in various villages.


20

The 3 highest total arsenic concentrations were 863, 572, and 328 µg/L. They were all found in the village of Madangram. Because the village of Madangram was a known high arsenic area, 10 out of 37 wells were chosen in this village to better understand the extent of arsenic contamination. Kirtipur-1 was another village with high arsenic in its groundwater. The fourth, fifth, and sixth highest total arsenic concentration (328, 242, 233 µg/L) were found in this village. Nine of 37 wells were chosen in this village. These results show that the occurrence of high total arsenic is not random, but is concentrated in specific villages. When installing a new well, extra care should be given to the well location and its proximity to high arsenic concentration areas. This could reduce the chance of the new well containing high arsenic. On the other hand, the speciation results seemed to be random across the villages. No village had a consistent level of arsenic (III) as a % of total arsenic. The range within each village could be fairly wide. Therefore, it was concluded that arsenic speciation was not village/area specific. The comparison between total arsenic and arsenic speciation showed no correlation. This implied that arsenic speciation could not be predicted by total arsenic. It was impossible to derive any information on speciation using arsenic test methods that measured total arsenic only. Additional techniques such as separation of arsenic (III) from arsenic (V) were necessary to determine speciation. The high percentage of arsenic (III) as a percentage of total arsenic in the tubewell water was also a health concern. This is because arsenic (III) is the more toxic form of arsenic compared to arsenic (V). Therefore, the arsenic positive wells should never be used for drinking and cooking purposes. It is also found that arsenic speciation correlates with oxidation-reduction potential (ORP), as expected from theoretical prediction. Figure 4.5 shows the correlation. The higher the ORP, the more oxidizing the water is. More arsenic will appear in its oxidized form, i.e. arsenic (V), than at its reduced form, i.e. arsenic (III). In other words, the % of arsenic (III) decreases with increasing ORP as more arsenic is in arsenic (V) form at high ORP. On the other hand, there is no correlation between total arsenic, pH, well depth, well age, number of users, and number of households on arsenic speciation. It is concluded that ORP is the best predictor of arsenic speciation.


21

y = -0.6325x + 57.356R2 = 0.4066

40

50

60

70

80

90

100

-70 -60 -50 -40 -30 -20 -10 0ORP (mV)

Ars

enic

(III)

as

% o

f Tot

al A

rsen

ic

Figure 4.5 – Correlation between % arsenic (III) and ORP

4.3 POU water treatment technologies

4.3.1 Ceramic filters

Manufacturing ceramic filters in Thimi, Nepal

Ceramic filters are probably the most commonly used point-of-use drinking water treatment option in Nepal. Currently, the white ceramic clay candle filters that are available in Nepal have very low flow rates between 0.2 to 0.3 liters per hour and unsatisfactory microbial removal when no disinfection is used. An Indian terracotta ceramic filter inspired an alternative option, which consists of a terracotta ceramic filter in the form of a disk. Ceramic filters are preferred over other filter media because Nepal has a long and established tradition in ceramic pottery making. The raw materials for ceramic making are easily available and many people are trained in this trade. Ceramic filters are also relatively cheap and easy to manufacture without requiring any sophisticated machinery. Team member Chian Siong Low collaborated with Hari Govinda Prajapati in the manufacturing of a ceramic filter disk in Thimi, Nepal. Thimi is a small town outside of the capital, Kathmandu, known for its ceramic pottery making in its traditional ways. Three main locally available raw materials were used in the making of the Thimi ceramic disks. They are red pottery clay, sawdust, and rice husk ash. The procedures for making the filters are as follows:


22

1. Prepare the raw materials. All these ingredients are sieved through a size 40 mesh sieve before they are used.

2. Mix by hand. The different ingredients are mixed together according to the specified proportions in Table 4-5.

Table 4-5 – Proportions of ingredients used in the first set of prototypes fired at 1000°C.

A B C D E Red clay 4 4 4 4 1 Sawdust 6 5 4 3 2.5 Rice husk ash 0 1 2 3 0 Water (for mixing) 1 2/3 1 2/3 1 ½ 1 1/3 >2

After combining the ingredients in a basin, water is added gradually to increase workability and the mixture is mixed by hand. The remaining volume of water is added until the mixture is thoroughly mixed.

3. Press in mold. A plaster mold to produce the shape of the filter disks was fabricated in advance specifically for the purpose of making these filter disks. The inside of the mold was lined with paper along its sides and the bottom to prevent the mixture from sticking. The mold was filled with the mixture to the top and compressed by hand during the process. The excess was scrapped from the top. The mold was then carefully inverted to prevent the mixture from falling apart. The paper that adhered to the mixture was peeled away carefully.

4. Dry (5-7 days). The finished filter disks were laid out to dry in the sun for 5 to 7 days. The higher the sawdust content, the more water is absorbed, the longer drying period is required. The dryer the mixture, the less likely it is for cracking to occur during firing.

5. Fire (1000-1070°C). The dried filter disks were ready to be fired in the kiln. The kilns were heated to between 1000 and 1070°C and the filter disks were fired for 12 hours to form finished ceramic disks. The fired ceramic disks had a lighter color and became slightly smaller due to shrinkage. The production cost for a 9-inch filter disk is NRs. 75 (US $1) and NRs. 190 (US $2.50) for the upper and lower ceramic containers.


23

Indian TERAFIL Terracotta Ceramic Filter

The TERAFIL terracotta filter consists of two cylindrical metal buckets with a TERAFIL ceramic disk filter fitted into the base of the top cylinder with ordinary grey cement. Figure 4.6 shows the TERAFIL filter assembly while the TERAFIL filter itself is shown in Figure 4.7. The TERAFIL filter ceramic disk is manufactured from a mixture of red silt clay (ordinary pottery clay), river sand, wood sawdust and burnt at a high temperature in a low cost kiln. The design of this filter comes from Surendra Khuntia, Scientist and Divisional Director of the Regional Research Laboratory in Bhubaneswar, India. The red terracotta clay, which is used to manufacture domestic ceramic ware, is abundantly available in India. During firing, the wood sawdust is burnt and the clay particles are sintered around the sand particles, leaving pores in between. According to Khuntia, the pores in a well-sintered TERAFIL are within 1 to 5 microns, and are not interconnected. A thin clay membrane of 50 to 100 micron thickness

separates the pores. The removal of most suspended particles occurs at the top surface of the TERAFIL, forming a layer of sediments. Over time, this may clog the filter and reduce flow rates. Therefore, it is recommended that the top of the TERAFIL clay disk be scrubbed once a day with a soft nylon brush to remove the sediments. Since the pores of the filter are not continuous and interconnected, the core of the TERAFIL should

not get clogged. With proper maintenance, the TERAFIL is expected to last more than 5 years.23 Currently, production cost is Indian Rupees (IRs) 15 to 20 (US$ 0.35 to US$ 0.47) for the TERAFIL disk and IRs 130 (US$ 3.02) for the complete filtration set with ceramic containers instead of the metal containers shown in Figure 4.6. Retail cost of the TERAFIL disk is IRs 25 (US$ 0.58) and IRs 180 (US$ 4.19) for the full set including ceramic containers. Evaluation of the TERAFIL and Thimi Filters

The performances of two TERAFIL units and the Thimi filters were evaluated based on their flowrate, turbidity removal, and microbial removal, according to procedures as stated in Section 3.

Table 4-6 – Performance summary of TERAFIL and Thimi ceramic filters. TERAFIL (MIT) TERAFIL

(ENPHO) Two Thimi

Filters Flowrate [L/hr] 1.1 � 1.9 5.9 � 6.9 0.2 � 0.3 % Turbidity Removal 33 � 94 97 � 99 57 � 84 % TC Removal 95 � 99.99 94 � 99 89 � 99 % FC Removal N.A. 80 � 100 100 % E.coli Removal N.A. 80 � 99 96 � 100 Cleaning (if any) Every 1 to 3 runs Every run Every run

Figure 4.6 – TERAFIL filter tested in MIT

Figure 4.7 – TERAFIL ceramic filter disk.


24

The TERAFIL showed good, although not flawless, technical performance in terms of turbidity removal with rates exceeding 85% most of the time; total coliform removal rates exceeding 94% all the times (17 of 18 run) without disinfection. Turbidity of the filtered water exceeded 1.0 NTU in only 5 of 18 runs. WHO Drinking Water Guidelines for turbidity is ≤5 NTU. The TERAFIL (ENPHO) showed particularly impressive performance since it was able to reduce the original turbidity of 70 NTU to less than 1.3 NTU in the filtered water. Total coliform removal rates always exceeded 94%. The most significant improvement of the TERAFIL (ENPHO) over the TERAFIL (MIT) was its faster flow rate, which was possible without sacrificing its microbial removal performance. However, this significant difference in flow rate could not be explained. At this time, a likely reason is the lack of quality control during manufacturing. For the Thimi ceramic disk filters, both have turbidity and microbial removal performances similar to the TERAFIL, but their flow rates were too slow for practical use. Required modifications include proportions of clay and sawdust used. The firing temperature can also be varied. Then again, when the flow rates are improved, the removal performance may decrease. Therefore, more prototypes need to be made and tested in Thimi before locally made ceramic disk filters are ready for widespread implementation in Nepal and potentially elsewhere. Both ceramic disk filters performed commendably in terms of the rates of turbidity and microbial removal. However, if these filters were to be recommended for use in compliance to the WHO Drinking Water Guidelines of zero coliforms per 100 ml, some form of post disinfection will be required. 4.3.2 Biosand filter Under the guidance of Dr. David Manz, an undergraduate researcher at the University of Calgary David Lee constructed the first intermittently operated slow sand filter in 1991 from a plastic garbage pail.24 After many design improvements and laboratory tests performed by Dr. Manz while he was a professor at the University of Calgary, the current plastic and concrete filter design includes a diffuser basin and a PVC pipe outlet for water level control. Water is simply poured in the top of the filter and microbial contamination removed as it flows through sand media and the schmutzdecke that forms at the sand-water interface (just as it does in continuous slow sand filtration). This innovative intermittent design, called the Biosand filter, contains five-centimeters of standing water above the fine sand media which functions to preserve biological activity when the filter is not being used. Because of its relatively small surface area, this scaled-down filter also has a much higher flow rate of 0.6 m/h (or 30L/hr) compared to 0.1 m/h of traditional slow sand filters. Much like its continuous counterpart, the Biosand filter requires no chemical additives with its primary materials consisting of sand and concrete (which can be found anywhere). Filter cleaning is simple and only necessary when the flow rate drops below a desirable level. Simply breaking up the biofilm present in the top ~5cm of sand by stirring gently and replacing the highly turbid water with relatively clean water will resume adequate flow of the Biosand filter, and thus there are no costs associated with filter cleaning or maintenance. This cleaning process is a smaller version of the filter harrowing of continuous slow sand filter treatment plants.25 This cleaning allows for the maintenance of a high bacterial population and minimally effects performance.


25

Members of the 2001 MIT Nepal Water Project tested about 40 existing Biosand filters in Palpa and Nawalparasi districts, and interviewed their owners. Because of the Biosand filters appropriate design and their proven success in laboratory settings, this filtration technology was introduced to a new region of Nepal. Villages in the Lumbini township were chosen for implementation of this Biosand Pilot Project for the following reasons:

• Observed success of Biosand programs in Palpa and Nawalparasi districts of Nepal.26,27 • Existing organizational structure and health focus of IBS village outreach programs

including women motivators who could train villagers in filter use, maintenance, and provide regular monitoring.

• Microbial well contamination. • Possible recontamination in households. • High incidence of waterborne disease (specifically amoebiosis).1 • Turbid well water.

An evaluation of the Lumbini Biosand Pilot Project can be found in 4.4.2. 4.3.3 Arsenic removal technologies Three arsenic removal technologies were evaluated and compared based on their technical performance. The three technologies are adsorption using Activated Alumina Manganese Oxide (A/M) with Poly-Benzyl Pyridinium Tri-Iodide (BP/I3) enhancement; adsorption using iron-coated sand; and coagulation with ENPHO�s powder (mix of ferric chloride, calcium hypochlorite and charcoal) followed by filtration. Activated Alumina Manganese Oxide (A/M) & Poly-Benzyl Pyridium Tri-Iodide (BP/I3)

The A/M and BP/I3 media are 2 proprietary products designed, manufactured, and distributed by a Massachusetts firm, Aquatic Treatment Systems, Inc.2 The A/M media is designed to adsorb arsenic (V). It also has limited ability to oxidize arsenic (III) to (V). The BP/I3 media is designed to provide a powerful on-demand3 oxidant to convert arsenic (III) to arsenic (V). Two treatment systems were set up and tested in Nepal, one with 800 mL of A/M media only, the other with 400 mL of BP/I3 and 800 mL of A/M media. The A/M only system was tested at 4 different locations, while the BP/I3 & A/M system was tested at 9 different sites. The technical performance of both systems were measured and compared. Table 4-7 shows a summary of the field test results.

1 The Biosand filter removes 100% of Amoebas by physical-chemical means (ie. No biological growth is necessary). In addition, dysentery can be of bacterial or amoebic origin. It is quite possible that the majority of ill health effects can be attributed to these protozoan and not bacteria. 2 Aquatic Treatment Systems, Inc. 50 Cole Parkway, Suite 26, Scituate, MA 02066. Phone +1-781-545-8858 or +1-888-772-AQUA (2782). Fax: +1-781-545-8848. 3 On-demand means that the BP/I3 oxidizes only when in contact with a reducing agent (e.g. arsenic (III), iron (II)). BP/I3 remains inert when reducing agents are not present.


26

Table 4-7 – Summary arsenic results on A/M and BP/I3 & A/M systems

Run #

Raw water total arsenic

(µg/L)

As(III) as % of total arsenic

A/M only treatment total arsenic (µg/L)

% Arsenic removal

BP/I3 & A/M treatment total arsenic (µg/L)

% Arsenic removal

1 242 91% < 5 > 98% < 5 > 98% 2 152 89% < 5 > 97% < 5 > 97% 3 337 91% <5 > 99% < 5 > 99% 4 323 73% < 5 > 98% < 5 > 98% 5 863 94% Not tested N/A < 5 > 99% 6 328 98% Not tested N/A < 5 > 98% 7 149 77% Not tested N/A < 5 > 97% 8 328 81% Not tested N/A < 5 > 98% 9 147 100% Not tested N/A < 5 > 97%

By comparing the arsenic removal results between the A/M only system and the BP/I3 & A/M systems, it appears that the A/M by itself is sufficient to reduce total arsenic to below WHO guidelines of 10 µg/L in all of the runs. Regardless of arsenic speciation, BP/I3 is not required. However, this is a short-term study. The A/M system was tested for only 4 runs with approximately 15-25 L of water treated; the BP/I3 & A/M system was tested for only 9 runs with approximately 40-50 L of water treated. When the A/M is subject to long-term use, its oxidizing capacity may be exhausted, leading to incomplete arsenic (III) to arsenic (V) oxidation and lowered arsenic removal. In that case, the use of BP/I3, a strong oxidizing agent, may prove to be useful in improving the removal effectiveness. However, it should be noted that the unit cost of the BP/I3 is about 10 times more than A/M. A long-term study is recommended. Iron Oxide Coated Sand

Arsenic adsorption onto iron oxides has been observed in various studies, and is one of several mechanisms believed to contribute to the presence of arsenic in groundwater and its subsequent mobilization due to dissolution of the oxides. Many researchers have previously used iron oxide coated sand to treat metal bearing industrial wastes and contaminated groundwater containing elements such as cadmium, strontium and chromium. Scientists at Bangladesh University of Engineering and Technology (BUET) have been investigating arsenic removal technologies in response to the overwhelming number of people affected by arsenic poisoning. BUET researchers found iron oxide coated sand to be an improvement over iron filings or iron chips due to the increased surface area and binding sites. Two iron oxide coated sand units have been assembled and installed in homes in 2 villages in Bangladesh. One unit achieved removal below 15 µg/L from an initial concentration of 226 µg/L. Over 7 months in operation, the unit had not reached the breakpoint of 50 µg/L, at which point the sand would be regenerated for further use. With minimum maintenance required, the user was very pleased with its performance.28


27

Scientists have adapted a wide variety of methods to produce iron oxide coated sand, which vary depending on the reagents used to the actual coating, drying temperatures and pH of the coating. Several methods adapt previous methods used with slight variations. Seven sands were made varying concentration, colloid treatment, and drying temperature. Methods were adapted from Ali et al. 2001, Joshi and Chandhuri, 1996, Bailey et al. 1992, and Lo et al., 1997. The general coating procedure follows: General procedure for coating sand with iron oxide Materials:

• 2 M Ferric nitrate • Sand (200 mL/80 mL ferric nitrate) • NaOH • 6 N commercial grade HCL • Distilled water

Method: 1. Wash sand in 6 N HCL for 24 hours. 2. Rinse with distilled water till free of HCL. 3. Place sand in oven to dry. 4. Titrate ferric nitrate to a pH 11-12 with NaOH while mixing. 5. Let colloids settle. 6. Discard the supernatant, and let excess liquid evaporate in hood. 7. Add sand to the colloids and mix well. 8. Heat sand in oven for 10-20 hours at a temperature ranging from 110ºC to 550ºC,

depending on the procedure. 9. Rinse sand with distilled water, then tap water. 10. Dry sand in oven (no specified temperature). 11. Store in capped bottles. 12. Add to test system. 13. Once breakthrough concentration is reached, pass 0.2M NaOH through the column (500

mL/200mL of sand). 14. Rinse with clean water to re-equilibrate the column.


28

Table 4-8 – Summary of produced iron oxide coated sands (IOCS)

IOCS Sand Grain Size Fe(NO3) 3 Conc. Coating Procedure Drying Temp. 1 Medium-Fine grain 0.25 M Supernatant removed,

Air dried colloids ~170-200ºC 10 hrs

2 Pass #30 sieve retained on #40 sieve

2.0 M Aqueous colloidal suspension

Held at 120ºC for 9hr, then ramped to 550ºC for 6hrs.

3 Local Nepal Medium-Fine grain

2.0 M Supernatant removed Held at 100-110ºC overnight then ramped to 550ºC held for 12 hrs.

4 Pass #30 sieve retained #40 sieve

2.0 M Supernatant removed, colloids partially air dried, and dried at 105-110°C

~ 110-150ºC for 17 hrs


2.0 M Supernatant removed, Air dried colloids

~ 110-150ºC for 17 hrs


2.0 M Supernatant removed, colloids partially air dried, and dried at 105-110°C

550ºC for 15 hrs


2.0 M Supernatant removed, Air dried colloids

550ºC for 15 hrs

Field-testing of iron oxide coated sand Coated sands were tested in 3 field sites: Pepperell, MA, Parasi, Nepal, and Salem, NH, with arsenic concentrations increasing respectively. The household prototype (Figure 4.8) was adapted from Ali et al. and consisted of polycarbonate tubing 3.7 cm ID packed with 10 cm of medium sized sand, followed by a 2 cm gravel layer, mesh screening to separate the gravel from the IOCS, packed to a depth of 40 cm. A porous pad prevented the IOCS from entering the spigot. Sands were flushed with two bed volumes of the sample water, or until outflow was free of visible particulate iron. Once the system was flushed, contaminated water was aerated either by addition to a bucket and stirring for approximately 5 minutes or by high flow from a hose, to allow precipitation of natural iron. Table 4-9 shows the effluent As concentration samples after flow through each IOCS.

Figure 4.8 – IOCS 4-7 in lab at MIT


29

Table 4-9 – Summary of field test results

IOCS1 IOCS2 IOCS4 IOCS5 IOCS6 IOCS7 Pepperell, Ma November, 2001 As~ 95µg/L

BDL -- -- -- -- -- BDL -- -- -- -- -- BDL -- -- -- -- --

Percent Removal 99% -- -- -- -- --

Parasi, Nepal January, 2002 As~ 242µg/L 17 176 -- -- -- -- 37 145 -- -- -- --

Percent Removal 97-85% 27-40% -- -- -- --

Pepperell, Ma March, 2002 As~ 101 µg/L BDL 72 32 BDL -- -- BDL 81 58 BDL -- -- 33 73 69 BDL -- --

Percent Removal 67-98% 20-29% 32-68% 93-99% -- --

Salem, NH March, 2002 As~1020 µg/L 565 -- 496 BDL 710 551 565 -- 710 13 620 682 623 -- 661 126 570 412 533 -- 646 186 540 631 386 -- 514 162 907 404 386 -- 723 194 887 805

Percent Removal 39-62% -- 29-51% 81-99% 11-47% 21-60%

Overall Average Percent Removal 67% 29% 42% 90% 31% 43%

BDL= Below Detection Limit (10 µg/L) Percent removal efficiencies varied widely amongst the prepared sands, but clearly IOCS5 was the most effective. The effects of the composition of the colloidal mixture and drying temperature most likely contribute to these differences. The composition of the colloidal mixture would increase or decrease the amount of iron oxide available for attachment to the sand. The more liquid present in the mixture, the more colloids are evaporated off while heating. The influent total arsenic concentration effects the percent removal rate as well. The type of iron oxide is also a factor; more crystalline structures have higher attachment strengths to the sand, but have less binding sites for arsenic due to their decreased surface area. The varied drying temperatures transform iron oxides into other forms. The flow rates of the columns were on average 103mL/min with a constant head of 3.7 inches. Increasing the contact time in the column would increase arsenic removal. Further investigation into the specific iron oxides formed and


30

the factors that affect their arsenic adsorption capability is recommended before proceeding with implementation of this technology. ENPHO Arsenic Removal System (ARS)

Starting in 2001, with funding from the Japan Red Cross and in collaboration with the Nepal Red Cross, ENPHO began distributing coagulation and filtration based household arsenic removal system as a pilot program. The plan calls for distribution of approximately 1,000 ENPHO Arsenic Removal Systems to people who are in the highest risk group from arsenic contaminated wells. This group of people has been identified by ENPHO through well sampling and a health survey conducted throughout various towns and villages in the Terai region. Households using well water contaminated with high concentrations of arsenic for drinking purposes and households found to have member(s) showing signs of arsenic poisoning are identified as high risk groups. The ENPHO system achieves arsenic removal by coagulation/co-precipitation followed by filtration. Arsenic removal through coagulation and co-precipitation using ferric chloride as the coagulant has several advantages over other treatment technologies in that all materials, including chemicals and the terracotta filters (manufactured in Thimi), are readily available. The total cost per household per year is NRs 1,250 (US$ 16.70) for the first year and NRs 730 (US$ 9.70) for the following years. The system consists of a 20 liter mixing bucket, a filtration unit consisting of an upper gagri (local term for a round shape vessel) containing a terracotta candle, and a lower collection unit consisting of another gagri, which includes a dispensing spigot.

Figure 4.9 – ENPHO Arsenic Removal System (ARS)

Filtration Gagri

Collection Gagri

Chemical Packet

Terracotta filter candle


31

ENPHO�s suggested procedure for usage is as follows. First, a packet or, so-called �tablet�, containing ferric chloride, charcoal powder, and sodium hypochlorite is added into the 20 liters bucket containing the contaminated well water. The water is stirred several times intermittently (approximately every 30 minutes) for 2 hours. After allowing the solids to settle, the water is poured into the upper gagri, which contains the filter. The treated water is then collected in the lower gagri. Scope and Description of Experiments Experiments were carried out in two phases. The first phase of experiments consisted of tests performed in Nepal in order to evaluate the performance of ENPHO Arsenic Removal System when ENPHO�s recommended procedure for using the system was used. In addition to arsenic removal, the fecal coliform removal rate of the system was evaluated using the membrane filtration method. During the second phase, experiments were performed to investigate ways to improve the efficiency of the ENPHO Arsenic Removal System. The second phase experiments were performed in field locations in Pepperell, Massachusetts and Salem, New Hampshire. First Phase Evaluation Results Overall, the ENPHO Arsenic Removal System yielded good arsenic removal efficiency. Table 4-10 shows arsenic concentrations of samples taken before and after the treatment.

Table 4-10 – Arsenic removal results for Parasi

Sample # Arsenic Concentration Untreated (µg/L)

Arsenic Concentration Treated (µg/L)

Percent Arsenic Removed (%)

1 91 17 81 % 2 95 13 87 % 3 97 11 88 % 4 221 9 96 % 5 197 17 91 % 6 198 13 94 % 7 277 16 94 % 8 276 22 92 % 9 274 21 92 %

These results show that with source water arsenic concentration ranging from 91 to 277 µg/L, the system removed arsenic by 81-96%, with treated water arsenic concentration consistently below the Interim Nepal arsenic guideline of 50 µg/L. The membrane filtration tests performed for fecal coliforms showed a good reduction of fecal coliform bacteria in the treated sample. Fecal coliform bacteria colonies could not be observed in many treated samples. On average, 99% reduction of fecal coliforms was observed.


32

Second Phase Evaluation Results Different ferric chloride doses were tested to determine appropriate coagulant dose. The results indicate that the current ferric chloride dose of 80 mg/L suggested by ENPHO, seems to be appropriate. In addition, preliminary test results indicate that the current mixing/settling regime may be modified without sacrificing arsenic removal efficiency: mixing time can be reduced from once every ½ hour for 2 hours to once only, and the overall settling time from 2 hours to 30 minutes. Conclusions for Arsenic Removal Technology A comparison of the above 3 treatment technologies on their removal effectiveness, costs, and availabilities is summarized in Table 4-11.

Table 4-11 – Comparison between different technologies for arsenic removal

Arsenic removal percentage

Cost of media/chemicals

Availability

A/M 95 � 99% US$ 2.80 per year Sold in US only Iron coated Sand 11 � 99 % US$ 5.70 per year Yes ENPHO ARS 81 � 96 % US$ 9.70 per year Yes

Several key recommendations can be made based on this above arsenic study. They are:

• Further investigations in the A/M media, iron coated sand, and ENPHO ARS regarding their technical, social and economic aspects are needed.

• For the technical aspect, the long-term capacity of A/M media, and iron coated sand should be assessed.

• The treated water should be tested for the full set of water quality parameters in the Nepali (or WHO) drinking water standards.

• For the social aspect, issues regarding the ease of setup, operation and maintenance, and the perceived quality of the treated water should be addressed.

• For the economic aspect, a users� willingness-to-pay study is suggested to understand how much the villagers can afford.

4.4 Implementation programs 4.4.1 Sodium hypochlorite generation in Kathmandu Introduction

A continuous and affordable supply of a reliable chlorine disinfectant is an essential component of any chlorination program intended to improve health through household water disinfection. The CDC Safe Water System suggests local manufacturing of a specific product for household disinfection programs, since products such as bleach and bleaching powder, which are originally intended for different uses (washing and housecleaning), may create acceptance and reliability problems.29


33

Among the 3 main options for procuring hypochlorite solution � importation of the finished product from abroad, importation of commercial bleach or bleaching powder from abroad and transformation into a disinfectant within the country of use, and local manufacturing using on-site hypochlorite generators � the last one was suggested30 as the most appropriate for developing countries. Therefore, the MIT Nepal Water Project team implemented a hypochlorite generation program in Kathmandu, Nepal in January 2002, in collaboration with the water research institute ENPHO (Environmental and Public Health Organization). In addition to providing a reliable source of disinfectant solution for chlorination programs, on-site hypochlorite generation had the economic goal of supporting local entrepreneurs in developing a profitable social business. 4 For this reason, a business plan for the micro-enterprise that would operate the generator and market the hypochlorite solution was prepared. Background

Before January 2002, ENPHO was manufacturing a 0.5% calcium hypochlorite solution commercially know as Piyush using bleaching powder imported from India. There were 2 major problems with this process: − Bleaching powder was not always available from the wholesaler; therefore Piyush

production was subject to uncontrollable discontinuity. − During the preparation of the stock solution, consistent lime precipitate was formed;

therefore, overnight settling was required before bottling the supernatant and the precipitated lime posed a disposal problem.

The sodium hypochlorite on-site generation process introduced in January 2002 aimed to solve these problems, and to provide, at the same time, an improved product. Basic requirements for the new formulation were to have the same available chlorine content, possibly lower turbidity and at least equal stability than the previous one. The hypochlorite generator and the new production process

In January 2002, the MIT Nepal Water Project team installed the SANILEC-6 hypochlorite generator donated by Severn Trent De Nora at ENPHO�s lab and operation and maintenance procedures were established and taught to ENPHO�s personnel. The SANILEC-6 unit, as shown in Figure 4.10, transforms a brine solution of water and common salt (sodium chloride) into sodium hypochlorite by electrolysis (see reaction below). The unit produces up to 2.7 kg of available chlorine with a concentration between 0.5 and 0.8 % in a 24-hour production cycle. This unit was considered as preferable to other similar ones, for a wide range of reasons, including minimal safety requirements, ease-of-use, flexibility and portability. NaCl + H2O → NaOCl + H2 Overall sodium hypochlorite generation reaction

4 For the meaning of �social business�, the definition suggested in Alter S. K. (Managing the Double Bottom Line: A Business Planning Guide for Social Enterprises, Save the Children Federation, Washington, DC, 1999. Available on-line: http://www.mip.org/pubs/mbp/managing_the_double.htm, 3/9/02) is adopted, according to which social enterprises operate with the double goal of being financially self-sufficient meanwhile creating economic opportunities for the poor.


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The reaction tank

The electrolytic cell

The transformer/rectifier

The Tee-base

Figure 4.10 – The SANILEC-6 sodium hypochlorite generator The generator was installed on the terrace of ENPHO�s building where ventilation, easy access to a water supply and a power source were provided. Two forms of common salt (granular and refined) were locally available and were tested in 3 different production cycles. Both forms were found adequate to generate a 0.5% available chlorine solution, but the refined salt produced a solution with lower turbidity. Thirty grams of salt per liter of water and a 16.5 h. generation cycle were determined to be necessary to reach the targeted chlorine concentration and produce 150 liters of disinfectant. Once produced, the bulk solution was manually bottled in 60-mL plastic bottles. During the production cycles, carbonate salts naturally occurring in hard water can scale the electrodes. Therefore, a cleaning procedure has to be performed on a regular basis (usually once a week). Quality evaluation of the new sodium hypochlorite product A major issue in the new manufacturing process was reliability in terms of quantity of solution in each bottle and stability of the available chlorine concentration. The average content of hypochlorite solution was found to be 55.3 g per bottle over a sample of 20 bottles, with a standard deviation of 4.9 g. The average available chlorine concentration was 0.51%, with a standard deviation of 0.04% over 3 tested bottles. Sodium hypochlorite is known to be an unstable solution, but the decay rate is minimized at low concentration (as in the present case) and if proper protection against sunlight, heat or contamination with iron is provided. For these reasons, caution is suggested both in the manufacturing and in the bottling process, as well in post-production storage, to ensure long-term stability. In particular, in the production process, contact between the hypochlorite solution and metallic parts must be avoided. High decay rate (0.10% per month) occurred in one batch because of use of an iron spigot, subsequently replaced by a PVC spigot. The solution from a properly conducted batch showed an average decay rate of 230 mg/L (0.023%) per month over the first 3 ½ months. This decay rate might be considered acceptable; however, greater stability might be achieved by alkalinizing the solution above pH 12 with sodium hydroxide.


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Chlorine demand of tap water in Kathmandu was found to be about 0.5 mg/L and thus a sodium hypochlorite dose of 3 drops per liter (about 1.5 mL/L) was proven adequate to provide a free residual chlorine level above 0.2 mg/L. However, further investigation of the actual chlorine demand in different seasons and in different areas of the country is suggested. Based on the outcome of such survey, daily household sodium hypochlorite consumption may be estimated and appropriate re-design of the bottle and the dosing cap can be undertaken. Economic analysis of sodium hypochlorite production

Production cost of bulk sodium hypochlorite solution was NRs 5.0 per liter (US$ 0.07) and NR 5.4 for a 60-mL bottle. The cost analysis shows that the bottle contributes more than 80% to the total cost, therefore a lower cost per bottle could be reached by using larger packaging or a refill option. Piyush micro-enterprise business plan

Production cost is only one of the elements that the micro-enterprise producing Piyush should consider in its business plan. From the financial point of view, the fundamental element for a sustainable business consists in having a sufficiently large pool of customers to break-even fixed and variable costs. To do this, the micro-enterprise should focus on 2 main aspects: First, it should carry out a survey of the targeted market and clearly identify customer�s needs. Hospitals, schools and NGOs involved in chlorination programs are potential customers easily identifiable in Kathmandu, and they might provide a reliable source of revenues because of the large amount of bulk solution needed. In addition, they might require comprehensive water treatment and monitoring services, which the micro-enterprise could provide in addition to the sodium hypochlorite supply for a premium price. In contrast, the household segment is much more dispersed; therefore, specific distribution and promotion strategies are required. Local retailers or health committees, who have a direct relation with the households, could be involved both in the marketing and in the distribution, and, at the same time, would have an opportunity to increase their income. In general, it is important that potential customers recognize the value of safer water, and social marketing could be a technique to increase household interest for the product and their willingness to pay for it. Second, the micro-enterprise must adopt an accounting system independent of ENPHO, in order to clearly identify internal costs, as well as subsidies and external support. ENPHO can help the micro-enterprise by sharing personnel and materials or by committing to buy a given amount of Piyush on a regular basis. Nevertheless, a transparent accounting system that accounts for these economic incentives is essential to make the micro-enterprise able to evaluate the actual performance and the financial success of their business. Finally, it is important to notice that the Piyush micro-enterprise has the opportunity to play a relevant role in the economic and social development of Nepal. By guaranteeing supply of a product useful to improve public health and by creating a reliable income to its own employees


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and associated retailers, the micro-enterprise will promote development in an area of the world surely in need of it. 4.4.2 Lumbini pilot studies Now in the third year of its existence, the MIT Nepal Water Project has progressed from field investigations of source water quality to community implementation programs for point-of-use water treatment technologies. In January 2001, a pilot study of household chlorination was established in Lumbini, Nepal. In January 2002, the MIT Nepal Water Project returned to Lumbini to evaluate the success of the household chlorination pilot study and begin the implementation of a second pilot study involving the Biosand water filter. Lumbini was chosen for the site of these initial pilot studies because of its close ties to the MIT Nepal Water Project and because of the strong presence of local organizations dedicated to safe water provision and the prevention of waterborne disease. The MIT Nepal Water Project has worked closely with the International Buddhist Society (IBS) in Lumbini and its founder Bhikku Maitri to ensure the long-term success of these implementation programs. Prior to MIT�s involvement, IBS had installed over 40 deep public wells for rural villagers and hired 7 women motivators to conduct health education in the region. Now, through the Lumbini Pilot Programs, 36 households and 4 schools in the region have received Piyush disinfectant and chlorination vessels, and 12 households and schools in 5 different villages have received Biosand filtration units. The actual reach of the program has gone beyond the small number of households that have received the treatment technologies. A great majority of the 10,000 villagers living within the 17 IBS villages have now been exposed to these treatment technologies, either directly though school or household use, or indirectly through the observation of fellow villagers. Household Chlorination Study The Lumbini Household Chlorination Pilot Study was based on the Centers for Disease Control and Preventions Safe Water System Program. This Safe Water System has 3 key components: (1) point-of-use treatment of contaminated water using locally produced sodium hypochlorite solutions (NaOCl), (2) safe water storage in containers specially designed to prevent recontamination, and (3) behavioral modification techniques designed to influence water handling and storage behavior and increase basic awareness of the benefits of safe water. Through the use of ENPHO�s Piyush disinfectant, and modified storage vessel systems created from locally available plastic buckets, the household chlorination pilot study introduced the first two components of the CDC�s program to Nepal. The results of the January 2002 evaluation showed that the Lumbini Pilot Study had successfully established household chlorination as a socially acceptable approach to water treatment in Lumbini, Nepal and created a high level of brand recognition and demand for Piyush chlorine disinfectant in the region. Although health surveys showed reductions in waterborne disease among participants, the Lumbini Pilot Study fell short of its expected reductions in microbial contamination in stored water. Proper free chlorine residuals were rarely observed in household chlorination systems, and bacterial recontamination was not uncommon (Sullivan, 2002). Household chlorination has been used for emergency water treatment in the developed world for many years and with the exception of scale, is similar to the disinfection process used by major


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water treatment facilities throughout the United States. Thus, these challenges cannot be attributed to the technical design of the treatments systems as chlorination effectively remove bacterial contamination and provide microbially safe water. This failure was likely due to improper household use of both disinfectant and storage vessels. This points to the need for education programs to accompany technologies intended for household use. The CDC separates the components of its Safe Water System program, upon which the Lumbini Household Chlorination Pilot Study was based, into two categories, hardware and software. Hardware refers to the technology or product components of a program, in this case the Piyush solution and chlorination vessel. Software refers to the components of the program designed to encourage the adoption and proper use of hardware. The difficulties with household chlorination experienced in Lumbini can be remedied through an enhancement of the software components of the program. This should involve the development of education programs designed to teach users the benefits of household chlorination and the proper use and handling of household chlorination systems. These user education programs could be incorporated into the programs already in place in Lumbini through the IBS women motivators. The IBS motivators are already familiar with the chlorination program and were involved in both health data collection and user instruction during the pilot study. Their participation has been central to the success of the household chlorination pilot study both because of their educational and motivational skills and because of their close contact with village women in the Lumbini region. They should therefore play a substantial role in any expanded program of household chlorination. Once the user education programs have been developed, the household chlorination program in Lumbini should be expanded to include more villagers in the region. In order to complete this expansion in a sustainable manner, full or partial cost-recovery should be explored for some components of the program. To assess the potential for user contributions in Lumbini and set prices for Piyush disinfectant and storage vessels, �willingness-to-pay� assessments should be made. If cost-recovery appears possible, program expansion should be encouraged. If cost-recovery appears unrealistic, the International Buddhist Society and other program sponsors should evaluate the potential for continued program subsidies and determine if expansion is still desirable. This analysis will be completed in June 2002. Biosand Filter Pilot Project

The Biosand Filter Pilot Project introduced 12 innovative intermittently operated slow sand filters into homes and schools in 5 different villages of the Lumbini District. Constructed in the Nawalparasi District by a local tradesman, Durga Ale, Biosand filters and their media were transported to Lumbini villages where they were commissioned during the first week of January 2002. While technically sound procedures were followed for both filter construction and commissioning, the importance of protecting the biofilm and schmutzdecke did not seem to be understood by both users and those installing the filters. Furthermore, flow rates dropped sharply following installation, which suggests a problem with the sand source or sand preparation procedure. In addition, basic filter operation and maintenance did not appear to be practiced although filter owners expressed a desire to become more educated about their filters. In fact, one filter owner said (through various translations), � Just tell us how to clean it, use it, maintain it, and we will.� It is not a question of whether people have the capacity to learn essential


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Biosand filter principles; it�s a question of them being provided the opportunity to learn and the subsequent thoroughness of this education. Expanding the Lumbini Biosand pilot project offers opportunities to refine the existing Biosand construction, distribution, and education process. Various modifications to building and filter installation could be easily applied in the case of Lumbini such as improvement of media preparation. This could include selection of a microbially safe sand source, buying sand in bulk, and modification of the media sieving process currently practiced. Additional recommendations include involving the community in media sifting and washing, disinfecting the filter standpipe using chlorine solution, and flushing filters with ~100L of water following installation and cleaning. As necessary to the successful implementation of Biosand filters as it is to household level chlorination, educational programs must accompany the dissemination of the Biosand filter technology. Filter users should be educated not only in basic filter operation but also in basic filter maintenance. Simply warning users of potential problems before they occur can solve many potential filter problems. This education should include how to clean the filter when necessary, how to prevent filter clogging, the importance of not moving the filter following installation, and the importance of keeping the diffuser basin in place. To best transfer this knowledge in the case of Lumbini, women motivators and other community educators should, themselves, become educated. This can be accomplished through hands-on training sessions and the preparation and translation of educational material such as a Biosand filter users guide into Nepali. Following the commissioning and initial education described above, continuing education and connection to the filters should be established. Since essentially no structural filter maintenance or new parts are required, continuing Biosand filter education could be easily incorporated into the existing health education programs provided by the women motivators. This would be a natural extension of their current role and would include motivating villagers to continue to use the deep public tubewells (which they already do), reminding users of the defined key educational points for Biosand success, and possibly cleaning taps monthly with liquid chlorine solution (if deemed necessary). Any questions that may arise during village visits could be answered by a support structure at the International Buddhist Society. Much like the Lumbini Chlorination Pilot Study, involving women motivators will automatically result in the inclusion of village women in Biosand filter operation. Lumbini Pilot Study Conclusions

Both Lumbini Pilot Studies demonstrate the essential role of integrating both the software and hardware components of implementation programs. Failure of the chlorination systems and Biosand filtration units to perform properly in the field can be attributed to the disconnect between the technology beneficiaries and those responsible for design and implementation. Hardware should be designed so as to best minimize local software issues that are not easily solvable through education programs. Based on field experience, the following were determined to be key to the successful implementation of new technologies: • Form partnerships with existing local organizations to ensure the sustainability of

implementation programs; • Include user groups, particularly women to connect local demand with appropriate design;


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• Develop motivational program components to encourage adoption of technologies; • Develop educational program components to ensure proper use of technologies; • Include schools as fora to transfer the knowledge of new technologies and to promote their

educated dissemination; • Start with small-scale pilot studies to best gauge social acceptability and demand for new

technologies; • Set goals and measurable indicators that may include reduction of waterborne disease,

percentage of technologies functioning properly, or number of filters commissioned. Although neither technology has been able to perform flawlessly in the field, the pilot studies in Lumbini can be considered a success for two reasons. One, the pilot studies have exposed a large number of villages in the region to both household chlorination and biosand filtration and this has generated a high level of awareness and demand for the technologies in the region. It remains to be seen if this demand can be translated into some level of cost-recovery and monetary or labor-based user contributions. Two, the pilot studies have provided the MIT Nepal Water Project with insights into the rewards and challenges of point-of-use technology implementation in developing countries. These insights can be used to refine and expand the existing programs in Lumbini and to develop future implementation programs in Nepal to apply appropriate microbial and arsenic removal technologies identified by the MIT Nepal Water Project.


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5. Conclusions The MIT Nepal Water Project 2001-2002 team carried out lab research and field surveys in Nepal in January 2002 to address several water quality issues, and eventually to contribute to improving the health situation in Nepal. Tubewell microbial contamination was investigated in Butwal and Lumbini, using fecal coliform, total coliform, and H2S-producing bacteria tests. For the choice of membrane filtration culture media selected for microbial enumeration: either EC with MUG or m-ColiBlue24 for E.coli, m-FC with rosalic acid medium for fecal coliform, and m-ColiBlue24 for total coliform. The H2S P/A tests were found not to require incubation at the proper 35 degree C temperature, but could give the same accurate results when samples were held at ambient temperature ranging from 5-30 ºC. H2S P/A showed perfect correlation at >15 CFU/100 mL and good correlation at 0 CFU/100 mL. It is found that generally, incubation would make the sample turn back within 24 hours if the well was contaminated. However, without incubation, the sample would still turn black in 48 hours if the well were contaminated. Therefore, incubation was not deemed necessary, because the contaminated sample would still turn black given a long enough reaction time. In Butwal and the surrounding areas, 42% percent out of 163 wells tested positive with the P/A H2S test. Contamination was found to be closely associated with the use of cow dung during the construction of the tubewell. Recommendations for the tubewell maintenance program include regular monitoring for microbial contamination, education of users, and increasing sense of ownership of the villagers. Since 2001, the Rural Water Supply and Sanitation Support Program (RWSSSP) by the Finnish International Development Co-operation Organization (DIDC) found that 9.8% of 1508 samples in the Districts of Rupandehi, Nawalparasi, and Palpa had over 10 µg/L of arsenic, the WHO current guideline. Arsenic speciation tests at 37 wells showed, on average, 79% of the total arsenic was in the more toxic arsenic (III) form. The removal of arsenic is therefore highly necessary. In addition, pre-oxidation of arsenic (III) to (V) was essential to improve arsenic removal efficiency for many adsorption-based treatment technologies. In terms of POU treatment technologies, the TERAFIL filter showed good, although not flawless, technical performance in terms of turbidity and microbial removal. However, if this filter was to be recommended for use in compliance to the WHO Drinking Water Guidelines of zero coliforms per 100 ml, some form of post disinfection will be required. The A/M arsenic removal technology was very successful in removing arsenic. The A/M only and the BP/I3 & A/M systems were tested with raw water total arsenic between 147 to 863 µg/L. In all of the above tests, the treated water contains non-detect level (<5 µg/L) of total arsenic, which is below the WHO guideline of 10 µg/L total arsenic. By comparing the arsenic removal results between the A/M only system and the BP/I3 & A/M systems, it appeared that the A/M by itself was sufficient for arsenic removal. BP/I3 is not required.


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Of 7 iron oxide coated sands produced, IOCS5 gave the highest total arsenic removal rate of 81-99%. These results are promising, however, detailed testing and evaluation of the iron oxide properties, as well as sufficient resources allocated to production of the media, is crucial before iron oxide coated sand technology could be implemented for point-of-use arsenic removal in Nepal or other developing countries. The evaluation of the ENPHO Arsenic Removal System showed that this system can be used to achieve effective arsenic removal, capable of reliably reducing arsenic concentration below the interim Nepali standard of 50 µg/L. The treated water arsenic concentration range of 9 to 22 µg/L was observed when the source water arsenic concentrations were in 90 to 300 µg/L range. While ENPHO Arsenic Removal System is a viable option that can be immediately implemented in order to address a growing problem, several drawbacks are present. These include the question of social acceptability and cost. Improvements may be made in regards to rendering the system more user-friendly by using a simpler procedure. The preliminary experimental results showed that this may be possible without significantly sacrificing the arsenic removal efficiency. On the other hand, it is uncertain whether the cost can be reduced, and it is recommended that this be further investigated by ENPHO. In the Sodium Hypochlorite Generation Pilot Program, a chlorine generator was installed in Kathmandu, at ENPHO�s lab to produce a 0.5% sodium hypochlorite solution for household disinfection. The major technical and organizational factors for successful commissioning of a sodium hypochlorite generation program were identified and the operating personnel was trained to run the disinfectant production procedure and the required quality control tests. Identification of large customers and adoption of a transparent accounting system are the main suggestions for the micro-enterprise that will deploy the chlorine disinfectant business. The financial sustainability of the micro-enterprise heavily depends on the adoption of the disinfectant at household level. The Lumbini Chlorination Pilot Study provided preliminary data about this subject. The Lumbini Pilot studies consisted of the Lumbini Chlorination Pilot Study and the Lumbini Biosand Pilot Study. Based on the January 2002 evaluation, the chlorination program has demonstrated that household chlorination is an appropriate approach to point-of-use water treatment the Lumbini region of Nepal. Acceptance of chlorinated water and demand for chlorination products in Lumbini appears to be significant. In spite of these successes, the hardware products themselves did not function as expected because they were not always used properly. Fortunately for the villagers in Lumbini, IBS has reacted positively to the chlorination pilot study and is committed to improving the effectiveness of household chlorination. This can be accomplished through a series of education programs, run by IBS and the women motivators, designed to introduce the missing �software� components in Lumbini, and improve household chlorination and water storage practices. As the pilot study has reached the end of its intended year-long period, it should be discontinued and replaced with a Household Chlorination Program designed to reach a larger number of villagers.


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Based on the success of the Lumbini Chlorination Pilot Study, household water chlorination is a viable method for providing safe water to Nepal�s rural villagers in the Terai region. The Safe Water System approach may also be appropriate for other subgroups of the Nepali population, particularly residents of the hills districts whose water treatment options are limited due to their remote locations, and residents of urban Kathmandu who must rely on the city�s distribution system, which is rarely chlorinated to proper levels. It may be valuable to establish additional pilot studies in these areas to evaluate the appropriateness of the Safe Water System approach.


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6. Appendix Instructions for Hydrogen Sulfide Media Preparation and Use The following chemicals are dissolved into 100 milliliters of distilled water or boiled tap water: Bacteriological peptone 40.0 grams Dipotassium hydrogen phosphate 3.0 grams Ferric ammonium citrate 1.5 grams Sodium thiosulphate 2.0 grams Sodium lauryl sulphate 0.2 grams These chemicals have been prepackaged in plastic bags into the correct amounts. As each bag is added to the media solution, empty it completely. 1) Begin slowly adding the bacteriological peptone to 100 milliliters of distilled or boiled tap water while stirring. When dissolved, add the remaining chemicals while stirring. Stir until dissolved. 2) Put 10 milliliters of water into a 11 milliliter vial and using a permanent marking pen, mark the water level. Empty the vial and use the mark on this vial to mark the remaining vials. 3) Place a sufficient amount of absorbent paper (toilet paper, kleenex, paper toweling ) to absorb 0.5 milliliters of media into each vial. This will generally be a piece of paper about 2 cm. by 3 cm. Then add 0.5 milliliters of media to each vial. 4) Loosely cap the vials and autoclave for 15 minutes. This can be done in a pressure cooker. Do not cover the vials with water. 5) After autoclaving, tightly cap the vials and store in a dark place. 6) Test the media by testing known contaminated water ( A very small amount of fecal material in water can be used.) This test should be positive. If this test is negative, repeat with another vial of media. If no tests are positive, the batch of media can be considered defective and should not be used. 7) Also, test distilled or boiled water. This test should be negative. If this test is positive, repeat with another vial of media. If no tests of clean water are negative, the batch of media can be considered defective and should not be used. 8) To test water: a) Wash hands carefully before using the test. b) Uncap a vial without touching the inside of the cap or the opening of the vial. c) Fill the vial to the 10 mL mark with the sample water. If sample water is collected in another container, make certain that the collection container is clean. Keep the sample water cool and


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put the sample water into the vial as soon as possible after collecting it -- no more than four hours after collection. d) Tightly cap the vial. e) Keep the vial at 35 degrees Celsius (approximately body temperature). f) If bacteria are present the vial will turn black within 24 hours. However, if the vial has not turned black, continue the test for another 24 hours. 9) Before reusing vials, empty their contents into a bucket of bleach solution and clean them thoroughly. Rinse thoroughly to remove all traces of bleach.


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7. References

1 World Bank Indicator Database, April 2002. Available: www.worldbank.org, accessed on April 25, 2002. 2 United Nations Children’s Fund Statistics, �Nepal Country Information�. Available: http://www.unicef.org/statis/Country_1Page122.html, accessed on February 29, 2002. 3 United Nations Children’s Fund Statistics, �Nepal Country Information�. Available: http://www.unicef.org/statis/Country_1Page122.html, accessed on February 29, 2002. 4 World Bank Indicator Database, April 2002. Available: www.worldbank.org, accessed on April 25, 2002. 5 United Nations Children’s Fund Statistics, �Nepal Country Information�. Available: http://www.unicef.org/statis/Country_1Page122.html, accessed on February 29, 2002. 6 World Bank Group, �Nepal at a glance�. Available: http://www.worldbank.org/data/countrydata/aag/npl_aag.pdf, accessed on February 29, 2002. 7 United Nations Children’s Fund, Water and sanitation database. Available: www.unicef.org, access on April 25, 2002. 8 World Health Organization, �Guidelines for Drinking Water Quality�, 2nd ed., Vol. 2 � Health criteria and other supporting information, Geneva, WHO, 1996. 9 MIT Nepal Water Project, 2001. 10 Nepal Red Cross Society, �Research on Arsenic Contamination in the Groundwater of Terai Nepal�, Final Report, Sep 2000. 11 Stetler, E. R. (1994), �Coliphages as Indicators of Enteroviruses�, Applied and Environmental Microbiology, Vol. 48, No.3, p. 668-670. 12 Craun, G.F.; Batik, O.; Pipes, W.O. (1983), “Routine coliform monitoring and waterborne disease outbreaks�, Journal of Environmental Health, Vol. 45, p. 227-230. 13 Shuval, H.I.; Cohen, J.; Kolodney, R. (1973), �Regrowth of coliforms and faecal coliforms in chlorinated wastewater effluent�, Water Research, Vol. 7, p. 537-546. 14 Grabow, W.O.; Du Preez, M. (1979), �Comparison of M-ENDO LES, McConkey and Teepol Media for membrane filtration counting of total bacteria in water�, Applied and Environmental Microbiology, Vol. 38, p. 351-358.


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15 Leclerc, H.; Mossel, D.A.A.; Trinel, P.A.; Gavini, F. (1976) A new test for fecal contamination, in Bacterial Indicators – Health Hazards Associated with Water, (eds A.W. Hoadley and B.J. Dutka). ASTM Publication: 635. ASTM, Philadelphia, PA. 16 Waite, W.M. (1985) A critical appraisal of the coliform test, Journal of the Institute of Water Engineers and Scientists, Vol. 39, p. 341-357. 17 Manja, K.S.; Maurya, M.S.; Rao, K.M. (1982) Simple field test for the detection of faecal pollution in drinking water. Bulletin World Health Organization. 60:797-801. 18 Cairncross, S. (1993) Environmental Health Engineering in the Tropics: an Introductory Text, 2nd ed., John Wiley & Sons, London, UK. 19 World Health Organization (1993) Guidelines for Drinking Water Quality, 2nd ed., Volume 1- Recommendations, WHO, Geneva. 20 RWSSSP (2002), Rural Water Supply and Sanitation Support Programme, Nepal Phase III 1999-2003 (Pamphlet). 21 Rijal, G.K., Fujioka, R.S., Ziel, C. (2000), Assessing the Microbial Quality of Drinking Water Source in Kathmandu, Nepal, Water Resource Research Center, University of Hawaii. 22 Mudgal, A. K., Dayal, R. (1995), Community Handpumps in the Terai Region: Assessment of Operation and Maintenance, UNDP-World Bank Water & Sanitation Program. 23 Khuntia, S. (2001), Regional Research Laboratory. Bhubaneswar, India. Personal Communication and TERAFIL reports. 24 Buzunis, B. J. (1995) Intermittently Operated Slow Sand Filtration: A New Water Treatment Process, University of Calgary Masters Thesis. 25 Collins, M. R., Eighmy, T. T., Malley, J. P. (1991), Evaluating Modifications to Slow Sand Filters, Journal AWWA, p. 62-69. 26 Lee, T. L. (2001) Biosand Household Water Filter Project in Nepal, Master of Engineering Degree Thesis, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA. 27 Paytner, N. (2001) Household Water Use and Treatment Practices in Rural Nepal: Biosand Filter Evaluation and Considerations for Future Projects, Master of Engineering Degree Thesis, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA. 28 Ali, Ashraf M., Badruzzaman, A.B.M., Jalil, M.A., Hossain, Delwar M., Hussainuzzaman, M.M., Badruzzaman, M., Mohammad, O.I., Akter, N. (2001),


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Development of Low-cost Technologies for Removal of Arsenic from Groundwater, Department of Civil Engineering, Bangladesh University, Dhaka 1000, Bangladesh. 29 Centers for Diseases Control and Prevention, Safe Water System Manual, Section 5.1, CDC, U.S. Department of Health and Human Services. Available: http://www.cdc.gov/safewater/manual/ch_5.htm, accessed March 28, 2002. 30 Van Zyl, N. (2001) Sodium Hypochlorite Generation for Household Water Disinfection in Haiti, Master of Engineering Degree Thesis, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA.

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