Appropriate water treatment technology that can be applied

112 Pages·2009·2.54 MB·English

by  Christian Borovac

Appropriate water treatment technology that can be
applied on the household scale to the developing
community of Tenganan, Bali

A local community in Tenganan

Christian Borovac
Supervisors: Professor Carolyn Oldham and Jerome Bowen

This thesis is presented in partial fulfilment of the requirements for the degree of Bachelor of Environmental Engineering for
the University of Western Australia, 2009.

Abstract Borovac, C
Appropriate household water treatment in Tenganan

ABSTRACT

Global water scarcity is becoming an increasing challenge to the global community, particularly in
developing countries. Due to a lack of available resources, knowledge or skills many of these
developing countries are unable to upgrade their water supply to sustain the growing population. Non
Governmental Organisations can intervene to address these issues and implement appropriate water
supply systems. Household scale treatment technologies are a proven method for improving water
quality and have been widely used in developing countries. The benefit of decentralised technology is
that it is flexible and is generally more affordable than large scale centralised systems.

Engineers without Borders (EWB) have undertaken a water supply project for the developing
community of Tenganan, Bali, which lacks a reliable supply of water especially during the dry season.
The primary aims of the intervention were to improve the quality and increase the quantity of the water
supply. The EWB design included developing a distribution network from an alternative water source
and treating the water with slow sand filtration. This study, one part of the EWB project, aimed to
identify possible secondary household water treatment technology which could be sustainably applied
within the community. Filtration techniques, boiling, aeration and UV disinfection were the
technologies investigated, and each one was categorised depending upon its disinfection efficiency,
scale, sustainability, affordability and social acceptability.

Water quality at the household level and from the community‟s major water sources was measured.
Results indicated that coliform counts exceeded Indonesian guidelines both at the water source and
household level for all sub-communities. Manganese, iron and lead concentrations were also above
recommended guidelines in some communities.

Based on the water quality review, the final recommendation was to use a combination of centralised
and decentralised treatment to form a multiple barrier approach to improving the water quality. Slow
sand filtration in conjunction with both carbon and biosand filters are recommended for treatment of
an additional water source. This would greatly benefit the water quality and quantity in Tenganan.
The findings from this study will contribute towards project development in Tenganan and directly
benefit the local population. Furthermore it could be used as a guideline for implementing future
water supply projects in developing countries globally.

i
Acknowledgments Borovac, C
Appropriate household water treatment in Tenganan

ACKNOWLEDGMENTS

I would like to thank all the staff from the school of Environmental Systems Engineering for teaching
me over the past five years. I would specifically like to acknowledge my primary supervisor;
Professor Carolyn Oldham for supporting me throughout this dissertation. Thank you for providing
guidance and making yourself available for weekly meetings and discussions.

I would like to thank all the people at EWB who contributed to my understanding of Tenganan and the
water supply project. To Jerome Bowen; my EWB contact, Kim Brackman; project administrator and
Ian Cunningham, thank you for all your support. Thanks also to the other TAN members and both
Anna Price and Mat Thame who are both placed in-country. Without you I would not have had the
water quality data, which was vital for my recommendations. Thanks also to the people at Quantum
labs in Denpasar for providing the water quality information.

I would like to give special acknowledgements to David Stanton from the Centre of Ecohydrology.
Thank you for educating me on specific filtration mechanisms and highlighting their importance. You
helped to shape my recommendations and supported me through the entire project. Thanks to Chun
Woo Baek for helping me understand the hydraulics through the piping network. Thanks also to
Professor Steven Gorelick from Stanford University who gave me a background on water supply
projects in Chennai.

Thanks to my fellow EWB thesis colleagues; Nathan Cocks and Prema Bhautoo for providing me with
information vital to my project and supporting me over the course of the year. Thanks also to the
other final year honours students. Thanks must also go to my family and friends, who supported me in
my endeavours over the course of the year. Special thanks to my dad who provided valuable feedback
and support.
ii
Glossary Borovac, C
Appropriate household water treatment in Tenganan

GLOSSARY OF BALINESE WORDS

Adat: The traditional form of social regulation and organisation
Banjar: Sub-communities of the larger desa Tenganan. These are individual units with
different rituals, social structures and administrations
Desa: The village unit including the geographical area
Dinas: The Government structures of organisation and regulation
Kayehan: The Balinese term for bathroom
Subak: The group of users who control the allocation of the Buhu River for non-irrigation
practices.

iii
Acronyms and Abbreviations Borovac, C
Appropriate household water treatment in Tenganan

ACRONYMS AND ABBREVIATIONS

ADWG: Australian Drinking Water Guidelines
BSF: Biosand Filtration System
CAWST: Centre for Affordable Water and Sanitation Technology.
EWB: Engineers without Borders
HWTS: Household water treatment systems.
ICT: In-country team working in Tenganan
Lcd: Litres per capita per day
MDG: Millennium Development Goals have been decided by the UN. They have set
targets for improving conditions for developing countries.
MPN: Most probable number
NGO: Non-Governmental Organisation
NTU: Nephelometric turbidity units
PE: Polyethylene
POE: Point of entry water treatment which treats all household water
POU: Point of use water treatment which only treats drinking and cooking water
PSAB: Pengelola Sarana Air Bersih – The Balinese Government group responsible for
maintaining the Batu Asah system and developing the new water supply system.
PVC: Polyvinyl chloride
SKM: Sinclair Knight Merz Engineering Services
SODIS: A treatment solution involving filtration, aeration and solar disinfection.
SSF: Slow Sand Filtration
SSS: Small-scale systems treat water for a small community or a small family
TAN: Technical Assistance network
TCU: True colour unit
TDI: Tolerable daily intake values.
TWS: Tenganan Water Supply – The title of the upgrade to the water supply system.
WHO: World Health Organisation

iv
Table of Contents Borovac, C
Appropriate household water treatment in Tenganan

TABLE OF CONTENTS

1 INTRODUCTION .................................................................................................... - 1 -
1.1 INTRODUCTION AND AIMS .................................................................................................. - 1 -
2 LITERATURE REVIEW ........................................................................................ - 3 -
2.1 THE GLOBAL WATER PROBLEM........................................................................................ - 3 -
2.2 APPROPRIATE TECHNOLOGY ............................................................................................ - 3 -
2.3 CAPACITY BUILDING AND DEVELOPMENT .................................................................... - 4 -
2.4 WATER QUALITY ................................................................................................................... - 5 -
2.4.1 Water quality parameters...................................................................................................................... - 5 -
2.4.1.1 Physical ......................................................................................................................................... - 5 -
2.4.1.2 Biological ...................................................................................................................................... - 6 -
2.4.1.3 Chemical ....................................................................................................................................... - 7 -
2.5 DECENTRALISED VERSUS CENTRALISED SYSTEMS ..................................................... - 9 -
2.6 HOUSEHOLD WATER TREATMENT SYSTEMS (HWTS)................................................ - 10 -
2.6.1 Boiling .................................................................................................................................................. - 11 -
2.6.2 Filtration methods ............................................................................................................................... - 12 -
2.6.3 Aeration ............................................................................................................................................... - 22 -
2.6.4 UV disinfection (SODIS)...................................................................................................................... - 23 -
2.6.5 Household handling and storage of treated water ............................................................................... - 25 -
3 SITE BACKGROUND ........................................................................................... - 27 -
3.1 AREA AND LOCATION ......................................................................................................... - 27 -
3.2 CLIMATE ................................................................................................................................ - 28 -
3.3 SOCIAL STRUCTURE ........................................................................................................... - 30 -
3.4 SANITATION .......................................................................................................................... - 30 -
3.5 STAKEHOLDERS ................................................................................................................... - 32 -
3.6 CURRENT SUPPLY ................................................................................................................ - 33 -
3.6.1 Batu Asah ............................................................................................................................................ - 36 -
3.6.2 Other sources ....................................................................................................................................... - 37 -
3.7 PROPOSED WATER SUPPLY UPGRADE ........................................................................... - 39 -
3.7.1 Appropriate technology and capacity development ............................................................................ - 39 -
3.7.2 Technical design .................................................................................................................................. - 40 -
3.8 TENGANAN WATER TREATMENT ANALYSIS ................................................................ - 43 -
3.8.1 EWB sampling technique .................................................................................................................... - 43 -
3.8.2 2006 water quality results .................................................................................................................... - 44 -
3.8.3 Scale of treatment options ................................................................................................................... - 45 -
3.8.4 Household conditions in Tenganan ...................................................................................................... - 45 -
4 APPROACH AND METHODOLOGY ................................................................. - 47 -
4.1 WATER BALANCE ASSESSMENT ...................................................................................... - 47 -
4.1.1 Projected population growth ............................................................................................................... - 47 -
v
Table of Contents Borovac, C
Appropriate household water treatment in Tenganan

4.1.2 Demand ................................................................................................................................................ - 48 -
4.1.3 Supply .................................................................................................................................................. - 48 -
4.2 SITES CHOSEN FOR TESTING ............................................................................................ - 49 -
4.3 METHOD FOR SAMPLING................................................................................................... - 50 -
4.4 METHOD FOR TESTING ...................................................................................................... - 51 -
4.5 HYDRAULICS ......................................................................................................................... - 52 -
5 RESULTS ............................................................................................................... - 55 -
5.1 WATER BALANCE ASSESSMENT ...................................................................................... - 55 -
5.2 WATER QUALITY TESTS .................................................................................................... - 57 -
6 DISCUSSION ......................................................................................................... - 58 -
6.1 WATER BALANCE ................................................................................................................ - 58 -
6.1.1 Demand ................................................................................................................................................ - 58 -
6.1.2 Supply .................................................................................................................................................. - 59 -
6.1.3 Water balance assessment ................................................................................................................... - 59 -
6.2 CRITERIA CHOSEN FOR SELECTING WATER PURIFICATION TECHNOLOGIES .. - 59 -
6.2.1 Acceptable water quality standards .................................................................................................... - 60 -
6.2.2 Scale of treatment ................................................................................................................................ - 61 -
6.2.3 Costs and sustainability ....................................................................................................................... - 63 -
6.2.4 Maintenance and appropriateness of technology ................................................................................ - 64 -
6.2.5 Recommended operating flow rates .................................................................................................... - 64 -
6.3 HYDRAULICS OF THE SYSTEM ......................................................................................... - 64 -
6.4 SCENARIOS IN TENGANAN ................................................................................................ - 68 -
6.4.1 Capacity development ......................................................................................................................... - 68 -
6.4.2 Household handling and storage of water ........................................................................................... - 69 -
6.4.3 Scenario 1: Household treatment only ................................................................................................ - 69 -
6.4.3.1 Suitability of each technology ...................................................................................................... - 71 -
6.4.3.2 Recommendation ......................................................................................................................... - 73 -
6.4.3.3 Economic assessment .................................................................................................................. - 74 -
6.4.4 Scenario 2: Centralised filtration system followed by household treatment ...................................... - 75 -
6.4.4.1 Recommendation ......................................................................................................................... - 78 -
6.4.4.2 Economic assessment .................................................................................................................. - 78 -
6.4.5 Scenario 3: Treatment for alternative water sources ........................................................................ - 80 -
6.4.5.1 Recommendation ......................................................................................................................... - 81 -
6.4.5.2 Economic assessment .................................................................................................................. - 82 -
6.5 POSSIBLE SOURCES OF CONTAMINATION .................................................................... - 82 -
6.6 CONSTRAINTS AND LIMITATIONS................................................................................... - 82 -
6.7 POTENTIAL FURTHER RESEARCH .................................................................................. - 84 -
6.7.1 Further investigations .......................................................................................................................... - 84 -
6.7.2 Next stage of EWB Tenganan Water Supply project .......................................................................... - 84 -
7 CONCLUSIONS AND RECOMMENDATIONS ................................................. - 86 -
8 REFERENCES ....................................................................................................... - 88 -
vi
Table of Contents Borovac, C
Appropriate household water treatment in Tenganan

9 APPENDICES ........................................................................................................ - 92 -
9.1 APPENDIX A: TASK SHEET ................................................................................................. - 92 -
9.2 APPENDIX B: DEMAND TABLE .......................................................................................... - 96 -
9.3 APPENDIX C: SUPPLY TABLE ............................................................................................ - 97 -
9.4 APPENDIX D: ECONOMIC ASSESSMENT OF SCENARIO 1 RECOMMENDATIONS . - 98 -
9.5 APPENDIX E: ECONOMIC ASSESSMENT OF SCENARIO 2 RECOMMENDATIONS .. - 99 -

vii
List of Figures Borovac, C
Appropriate household water treatment in Tenganan

LIST OF FIGURES

FIGURE 1. ACTIVATED CARBON FILTRATION ON THE HOUSEHOLD SCALE (DVORAK 2008) ............. - 13 -
FIGURE 2. AN ACTIVATED CARBON PARTICLE SHOWING THE PORE SPACE AVAILABLE FOR
WATER FLOW (DVORAK 2008) ..................................................................................................... - 14 -
FIGURE 3. THE SETUP FOR A BIOSAND FILTER (VAN WIJK & CHRISTOFFERS 2005) ............................ - 16 -
FIGURE 4. THE SETUP OF THE POTTERS FOR PEACE FILTERS. THE PICTURE ON THE LEFT IS A
CROSS-SECTIONAL VIEW. THE CENTRAL PICTURE SHOWS THE SIMPLICITY OF
THE TREATMENT. THE RIGHT PICTURE SHOWS THE BASIC THREE TIER
APPROACH (CAWST N.D.; VAN HALEM ET AL. 2006) ............................................................... - 18 -
FIGURE 5. A 55µ ARKAL FILTER WITH 200 DISCS (ARKAL FILTRATION SYSTEMS 2009) ...................... - 20 -
FIGURE 6. SPECIFICALLY DESIGNED GROOVE ON THE DISC SURFACE (ARKAL FILTRATION
SYSTEMS 2009) ................................................................................................................................. - 21 -
FIGURE 7. AN AERATED TRAY WHICH IS USED TO TREAT WATER (SKINNER & SHAW 2003) ............. - 22 -
FIGURE 8. A PLASTIC BOTTLE BEING USED FOR SOLAR DISINFECTION (KAYAGA 2009) .................... - 24 -
FIGURE 9. ACCEPTABLE STORAGE VESSELS WHICH FIT THE SUGGESTED CRITERIA.
TRADITIONAL STORAGE VESSELS WHICH HAVE A HIGHER CHANCE OF
ALLOWING RECONTAMINATION ARE SHOWN ON THE LEFT. VESSELS ON THE
RIGHT ARE CONSIDERED APPROPRIATE FOR STORAGE (CAWST N.D)............................. - 26 -
FIGURE 10. A MAP OF BALI WITH THE LOCATION OF TENGANAN, DENPASAR AND
KEROBOKAN (BOWEN 2007) ......................................................................................................... - 27 -
FIGURE 11. AVERAGE MONTHLY TEMPERATURE IN DENPASAR .............................................................. - 28 -
FIGURE 12. THE AVERAGE MONTHLY RAINFALL IN DENPASAR ............................................................... - 29 -
FIGURE 13. AVERAGE MONTHLY SUNLIGHT PERCENTAGE FROM 1997-2005 (BOWEN 2009) ............... - 29 -
FIGURE 14. AN OVERVIEW OF THE TENGANAN AREA. DESA ADAT INDICATE THE
COMMUNITY BORDERS AND DESA DINAS REPRESENTS THE GOVERNMENT
BORDER AND AREA OF CONTROL. THE LOCATION OF THE 5 BANJARS ARE
CIRCLED (BOWEN 2006A) .............................................................................................................. - 31 -
FIGURE 15. THE STRUCTURE OF THE STAKEHOLDER’S RELATIONSHIP IN THE TENGANAN
WATER SUPPLY PROJECT. EWB AND WISNU HAVE COME TOGETHER AS NGO’S,
TO DESIGN A WATER SUPPLY SYSTEM AND THIS MUST BE IMPLEMENTED BY THE
PSAB ................................................................................................................................................... - 33 -
FIGURE 16. THE PERCENTAGE OF HOUSEHOLDS WHO EXPERIENCE TIMES WITHOUT WATER
(HAWKER & BRACKMAN JUNE 2009) .......................................................................................... - 35 -
FIGURE 17. THE EXISTING DISTRIBUTION NETWORK SHOWING BATU ASAH SPRING AS THE
MAJOR WATER SUPPLY SOURCE. THE SOLID LINES INDICATE FLOW THROUGH
THE COMMUNITIES. 2008 POPULATIONS ARE USED (HAWKER & BRACKMAN JUNE
2009) .................................................................................................................................................... - 35 -
FIGURE 18. A) TAP ON THE 2ND STREET AT TENGANAN PEGERINGSINGAN. B) THE BABI TUNU
DAM. C) TANK AT KAYOAN KETIPAT. D) BUKIT KAUH RAINWATER TANK
(BOWEN 2006C) ................................................................................................................................ - 38 -
FIGURE 19. THE PROPOSED DISTRIBUTION SYSTEM FOR THE BABI TUNU DAM UPGRADE ............... - 42 -
viii