GOVERNMENT OF PEOPLE’S REPUBLIC OF BANGLADESH
MINISTRY OF LOCAL GOVT. , RURAL DEVELOPMENT & COOPERATIVES
LOCAL GOVERNMENT DIVISION

International Workshop on
Arsenic Mitigation in Bangladesh
Dhaka, 14-16 January, 2002

ALTERNATIVE WATER SUPPLY OPTIONS
For Arsenic Affected Areas of Bangladesh


Alternative Water Supply Options
For Arsenic Affected Areas of Bangladesh
A theme paper for presentation and discussion at the
International Workshop on
Arsenic Mitigation in Bangladesh
Dhaka, 14-16 January, 2002

Prepared by:
M. Feroze Ahmed, Ph.D., FIE, MASCE
Professor of Civil/Environmental Engineering,
BUET, Dhaka-1000, Bangladesh

Published by:
ITN-Bangladesh
Centre for Water Supply and Waste Management
Civil Engineering Building, (3rd. Fl.)
BUET, Dhaka-1000, Bangladesh

On behalf of:
Local Government Division
Ministry of Local Government, Rural Development and Co-operatives,
Government of the People’s Republic of Bangladesh

January, 2002

[Cover design by Sazzad Mahmud. Printed by Progressive Printers Pvt. Ltd., Dhaka, Bangladesh]

EXECUTIVE SUMMARY

The water supply in Bangladesh is primarily based on groundwater. An estimate shows that the present population coverage by piped water supply is 13.1 million (10%) and manually operated deep tube well mainly in the coastal area is 8.1 million (6%). Dug/ring well, Pond Sand Filter, Shallow and Very Shallow Shrouded Tubewell and rainwater harvesting provide arsenic safe water to 2.8 million (2%). About 103 million (80%) people depend on shallow tubewell for water supply and remaining 2% people do not have any well-defined source of water supply. An estimated 29 million people, exposed to arsenic contamination in excess of 50m g/L through 27% contaminated shallow tubewells and few production wells in urban centers, will require alternative water supply.

The sources of water available in Bangladesh for development of alternative water supplies are groundwater, surface water and rainwater. Four groundwater based options, six surface water based options and few rainwater harvesting techniques have been experimentally adopted as alternative water supply options in Bangladesh. On the other hand, thirty community and household level arsenic removal technologies have been tried in Bangladesh to reduce arsenic contents of water of contaminated tubewells to acceptable levels. Deep tubewells, dug/ring wells, treatment of surface waters and few arsenic removal unit show good potentials for water supply in arsenic affected areas and are suitable for adoption in the national program. Most options are site specific and no single option can provide arsenic safe water in all areas or to people having wide variation in socio-economic conditions. Piped water supply, irrespective of source should be given priority where feasible considering convenience and better quality control. Rainwater harvesting has good potential at household level but a system completely based on rainwater appears to be too costly and the method is yet to be popular in Bangladesh. Standard manuals should be developed for all options for uniformity in practice.

The estimated capital cost to provide arsenic safe water to 29 million people exposed to arsenic content exceeding Bangladesh Standard varies from Taka 2.6 to 36 billion at 2001 price level depending on the type of options. However, the cost will be significantly reduced if the people in the low contamination areas are mobilized to use the safe tubewells in the area. Provision of water satisfying Bangladesh standard for arsenic will reduce the risk of incidences of excess lifetime skin cancer in the country from estimated 415,000 (0.321% of total population) to 55,000 (0.043%). An estimated, 1.875 million tubewells (25% of total tubewell) worth Taka 8.44 billion are likely to be abandoned for producing arsenic contaminated water exceeding Bangladesh Standard. About 73% of existing shallow tubewells providing safe water to 75 million (58%) people in the country may yield water with elevated levels of arsenic in future. A well designed active water quality monitoring program to test the safe tubewells at least once in a year is needed to be installed. The estimated yearly cost of monitoring of safe tubewell once in each year by field test kit is Taka 176 million. An institutional arrangement with greater role of Local Government is needed for installation, operation and maintenance of alternative water supply options and monitoring of water quality at the local levels.

Table of Contents (with links to the actual chapters)

Executive Summary

List of Abbreviations


1
INTRODUCTION

2
WATER SUPPLY SITUATION ANALYSIS
    1. Sources of Water Supply
      1. General
      2. Surface Waters
      3. Groundwater
      4. Rain Water
    2. Water Supply Situation
    3. Arsenic Problem
      1. Magnitude of the Problem
      2. Population Exposed
      3. Estimated Risk

3
WATER SUPPLY OPTIONS
    1. Introduction
    2. Alternative Arsenic Safe Water Sources
      1. Groundwater
      2. Surface Water
      3. Rainwater Harvesting
      4. Solar Distillation
      5. Solar Disinfection
    3. Treatment of Arsenic Contaminated Water
      1. General
      2. Oxidation
      3. Co-Precipitation and Adsorption Processes
      4. Sorptive Filter Media
      5. Ion Exchange
      6. Membrane Techniques
      7. Summary
    4. Piped Water Supply
    5. Screening and Monitoring of Drinking Water
      1. Screening
      2. Monitoring
    6. Costs

4
ARSENIC MITIGATION INITIATIVES BY DIFFERENT ORGANIZATIONS
    1. Department of Public Health Engineering
    2. Bangladesh Arsenic Mitigation Water Supply Project
    3. UNICEF
    4. NGO Forum for Drinking Water Supply and Sanitation
    5. BRAC
    6. Dhaka Community Hospital
    7. Asia Arsenic Network
    8. Grameen Bank
    9. Proshika
    10. AQUA Consultants
    11. Bangladesh Engineering and Technological Services

5
INSTITUTIONAL ARRANGEMENTS FOR SERVICE DELIVERY
    1. Past Experience
    2. Present Situation
    3. Apparent Transition
    4. Rationale for Giving Key Roles to Local Government
    5. Role of Communities, Private Sector and NGOs
    6. Role of Central Government
    7. A Framework for Capacity Building of Local Government

6
CONCLUSIONS
    1. Alternative Water Supply Options
      1. Deep Tubewell
      2. Piped Water Supply
      3. Treatment of Surface Water
      4. Dug Well
      5. Rainwater Harvesting
      6. Treatment of Arsenic Contaminated Water
    2. Research and Development Needs

7
REFERENCES

Appendix-1


List of Abbreviations

BAMWSP Bangladesh Arsenic Mitigation Water Supply Project.

BBS Bangladesh Bureau of Statistics

BGS British Geological Survey

BRTC Bureau of Research, Testing and Consultation

BUET Bangladesh University of Engineering and Technology

DANIDA Danish International Development Agency

DCH Dhaka Community Hospital

DFID Department for International Development

DPHE Department of Public Health Engineering

DTW Deep Tubewell

DWASA Dhaka Water Supply and Sewerage Authority

GOB Government of Bangladesh

HRD Human Resources Development

HTW Hand Tubewell

IG Infiltration Gallery

IRP Iron Removal Plant

ITN International Training Network Centre

LGD Local Government Division

LGED Local Government Engineering Department

LGIs Local Government Institutions

M&E Monitoring and Evaluation

MLGRD&C Ministry of Local Government, Rural Development & Cooperatives

NAMIC National Arsenic Mitigation Information Centre

NGO Non-Government Organization

NILG National Institute of Local Government

O&M Operation and Maintenance

R&D Research & Development

RDA Rural Development Academy

RWH Rain Water Harvesting

RWS Rural Water Supply

SDC Swiss Agency for Development and Co-operation

SSF Slow Sand Filter

SST Shallow Shrouded Tubewell

STW Shallow Tubewell

UNICEF United Nations Children’s Fund

VSST Very Shallow Shrouded Tubewell

WASA Water Supply and Sewerage Authority

WatSan Water and Sanitation

WHO World Health Organisation

WSS Water Supply and Sanitation

WSP – SA Water and Sanitation Program – South Asia of the WB

WB World Bank