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Arsenic Contamination and Mitigation
in Cambodia
Dr. Mickey Sampson
Resource Development International- Cambodia
Wells tested in Kandal
Estimated Population ImpactedUsing 2004 Census data for usage rates
Approximately 102,600 are exposed to arsenic in their drinking water
Sources of Error• People did not report accuratly their source in the census• Education has impacted sources• Better sources now available
Arsenicosis
Mitigation
Approaches
Education is Vital
InfotainmentKaraoke
Methods of Mitigation
• Alternate Water Supply/Sources– Surface Water– Rainwater– Hand Dug Wells (Rope Pumps)
• Removal Technologies– Iron Oxide Co-precipitation– Alumina Hydroxides– Highly technical Media/membranes
Surface Water
Concerns:• Very prone to pathogen contamination• Only available in some areas/season
Water must be treated for Pathogens before use• Boiling (problem storage)
• Ceramic Filter (Availability and proper use)
• Chemical Treatment (taste, cost, amebas)
Rainwater Harvesting
• Weather Dependent
• High cost of storage containers
• Storage Capacity
• Safe Storage
Best Option is when coupled with a well used for sanitation
Rainwater Harvesting
40,000 liters
Hand Dug Wells
• Initial Studies show water is significantly better chemically
• Is available in most high risk areas
• Water is more prone to Pathogenic contamination
• Protecting the source may help
0 20 40 60 80 100
46-70
21 - 45
0 - 20
Wel
l Dep
th (
m)
Number of Wells
As <= 10 ppb
10 < As <= 50 ppb
As > 50 ppb
Rope Pump
Removal Technologies
Nails
Sand Layer
Gravel Layers
Modified BioSand Filter or Kachan
0
50
100
150
200
250
300
350
400
450
Jul Aug Sep Oct
Month
Ars
en
ic C
on
cen
trati
on
(p
pb
)
Filter#1-in
Filter #1-out
Filter #2-in
Filter #2-out
Filter #3-in
Filter #3-outCambodian National Standard
77.2%
84.7%
85.5%
25.7%
45.4%
72%
13.2%
43%
46.7%
70.4%
25.2% 78%
Three different wells were part of the study. We found removal rates varied significantly as did the chemical content in each.
Average overall removal was 39.5%, 47.8% and 75.2%
Arsenic Removal vs. Phosphorus
y = 0.3507x - 0.4634
R2 = 0.7587
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00
Fe / P Ratio
Ars
enic
Rem
oval
%
\
Removal Technologies
• Only used as a last resort
• Technologies need further testing and evaluation
• Systems need to be low maintenance and inexpensive
Piped Water
Thank you
www.rdic.org
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