1. Groundwater Arsenic Occurrences in Bangladesh and Mitigation Options
Goldschmidt2015
Prague, CZ, August 2015
Groundwater Arsenic Occurrences in Bangladesh and Mitigation Options
Kazi Matin Ahmed, PhD
Department of Geology
University of Dhaka
Dhaka, Bangladesh

2. Groundwater as the Sources for Drinking & Irrigation Water

3. Map of Arsenic Occurrence
Survey
Survey
Add year with large fonts 3

4. Over 5 million wells tested!
Most severely affected areas are in the southern part of the deltaic plains
Some contamination in the north east, northwest is least contaminated
Hills in the southeast safe
Distribution is controlled by surface geology
Deeper wells are mostly safe
Change color for the 20-40% class to yellow 4

5. Geology and Arsenic Distribution

6. Basin Model

7. Impact of Arsenic on Rural Water Supply
Source: WaterAid Bangladesh

8. Possible Impacts on Rice Production
50% reduction
Delete one map, add the graph on yield reduction of rice
‘Parrot beak’
Duxbury et al 8

9. Number of People with Skin Lesions
Surveys identified around 30,000 having arsenical skin lesions
Overall prevalence is about 1 in 1000, however, local studies reported much higher numbers;
Argoss et al - double mortality rate due to CVD for exposure in access 150 ppb; Wasserman et al reported reduced intellectual development of kids.
Alan Smith predicts 1 in 100 dying of cancer at 50 ppb, and 1 in 10 at 500 ppb
Delete one map, add a picture of skin lesions 9

10. Arsenic Removal Technologies
Sono 45-25
A –Household ARTs: Alcan, Nelima, Read F, Shawdesh, Sono
B - Community ARTs: Sidko
Sidko
MAGC/ALCAN
READ-F

11. Well Switching

12. Alternative Safe Water Options

13. Deep Tube Wells
(GOB, 2002)

14. Rural Piped Water Systems
(GOB, 2002)

15. Subsurface Arsenic Removal

16. Number of People Exposed to >50 ppb
Change title
GOB, 2002 16

17. GOB/UNICEF 2009 MICS
The results of the Multiple Indicator Cluster Survey (MICS) in 2009 estimated that approximately 22 million people were exposed to arsenic concentrations above 50 μg/L, and approximately 36 million above 10 μg/L.
The results of the Multiple Indicator Cluster Survey (MICS) in 2013 estimated that approximately 19.6 million people were exposed to arsenic concentrations above the Bangladesh Drinking Water Quality Standard of 50 μg/L

18. Arsenic in BRAC WASH Area
Source: Nepal C Dey, Fazlul Karim and Sifat-E-Rabbi, Use of tubewell water for different purposes at household level: safety practices in rural Bangladesh, in Achievements of BRAC Water, Sanitation and Hygiene Programme Towards Millennium Development Goals and Beyond, Research Monograph Series No. 60, p11-31, Research and Evaluation Division (RED), BRAC.

19. Large Number of Untested Wells
50% of households
(53/105)
knowingly drink
from unsafe well

20. Possible Safe Water Options for Different Regions
Out of 19.0 million, 10.9 million people can be covered by Deep TW with No 6 or TARA hand pump
The rest 8.1 million people are to be covered by PSF, DW, AIRP etc
If well can be installed up to deep aquifer having gravel problem, nearly 5.7 million out of 8.1 million can be served with Tubewell 20

21. Concluding Remarks
Natural arsenic occurrence in the alluvial aquifer is and will remain as a major challenge for water supply in Bangladesh ;
A major public health concerns; thousands of patients with visible symptoms; likely impacts on food security;
A large number of mitigations options are available, DTW has been the most effective one;
Still millions are exposed to arsenic above current BD limit (50 ppb), number almost doubles if WHO provisional guide line value (10 ppb) is considered;
Targeted efforts are necessary to provide safe water to all who are still drinking water having As above safe limits;
Impacts of As on Irrigation and food security need special attention.

22. Thank you all!