1. Implementing Water, Sanitation & Hygiene
(WASH) Approaches During Emergencies
Guest Lecture at MIT D-Lab Class: Disseminating WASH Innovations
Tom Mahin
April 12, 2011

2. From CAWST

3. Emergencies - Natural Disasters, Conflicts & Outbreaks
Adapted
from
Lantagne &
Clasen 2009

4. Examples of Emergencies and Potential
Waterborne Pathogen Outbreaks
• Seasonal Flooding - significant potential for pathogen
contamination of shallow wells and springs and
flooding of latrines
• Earthquakes – damage to drinking water and
wastewater-sanitation infrastructure
• Conflicts - potential for inadequate water, sanitation &
hygiene in refugee/internally displaced persons camps
• Hurricanes/typhoons/cyclones/tsunami – flooding
(contamination of water sources) and damage to water
and sanitation infrastructure

5. Displacement of Large Numbers of People Increases the
Likelihood of Waterborne Disease Outbreaks

6. Cholera
• Cholera is caused by V. cholerae bacteria.
• There have been numerous outbreaks in
Sub-Saharan Africa in Asia and now in Haiti.
• Coastal countries are at particular risk
because the bacteria can survive very well in
coastal areas particularly in rivers that empty
to the ocean.

7. A Number of Waterborne Pathogens Cause Increased
Diarrhea Cases During Flooding
From Harris et al. 2008

8. Community Water Sources Before and After Flooding
Haiti (Gonaives) 2004
From Colindres et al. 2007

9. Cholera Outbreak - 1994
• Between July 14 and 17, 1994 approximately
800,000 ethnic Hutus fled Rwanda and sought refuge
in neighboring Zaire (now DRC). Many refugees
entered through the town of Goma, at the northern
end of Lake Kivu.
• A massive cholera outbreak spread quickly and very
high death rates resulted. The hard volcanic soil
prevented the building of traditional latrines and
Lake Kivu which was used for bathing and drinking
quickly became contaminated with cholera (Goma
Epidemiology Group,1995).

11. Examples of Different Chlorination Approaches
Used During Emergencies
• Water trucking
with chlorination
• Point of Use – Household Chlorination
(e.g. distribution of NaDCC tablets,
promotion of dilute sodium hypochlorite)
• Chlorination of community/municipal water systems at
either the reservoir tank or a water collection point
(well, tapstand on piped system, small spring, etc.

12. Chlorination and Cholera
• Chlorinating and maintaining a chlorine residual in
water used for drinking is a proven way of
significantly reducing cholera rates.
• However a number of challenges exist particularly for
rural areas.

13. Chlorination Challenges – Household Chlorination
• Providing large amounts of NaDCC (chlorine) tablets as
is required is logistically complicated and raises
significant long-term sustainability issues.
• Use of NaDCC tablets of significantly different dosages in
Haiti has made training in proper usage more difficult.
• Household bleach is more commonly available but is
more difficult to properly dose (e.g. varying % chlorine
& dosing of drops per gallon). In addition, bleach can
include perfumes and is perceived by some as meant for
laundry not drinking water.

14. One NaDCC Manufacturers Varying
Doses for Household Use
Medentech

15. Chlorination Challenges - Gravity Flow Systems
• Proper mixing of “batch” chlorine in reservoir tanks
is difficult because such tanks are usually designed
for settling/storage not mixing.
• Regular monitoring of chlorine residuals is an
important part of community systems but is under
performed in many rural areas.
• Solution – need both improved (more consistent)
chlorine dosing at tank and more frequent chlorine
residual monitoring

16. Potential New Approaches to Chlorination of
Community Systems during Emergencies

17. Point of Water Collection Chlorine Dispenser
From: Trickle Down: Chlorine Dispensers and Household Water Treatment by
Kremer et al. 2009

18. Chlorine
Dispenser
- Haiti

19. Chlorine Dispenser
From Fitzpatrick 2008

20. Communicating Proper Dose
From Kremer et al.

21. Challenges for Making Chlorination at Water
Collection Points (e.g. dispensers) Sustainable
• Common use of different size containers mean different
doses of chlorine. Solution may be to have
2 clearly marked chlorination points, one for
“1 gallon” jugs & one for “5 gallon” containers.
• Having a system that results in regular preparation of
replacement chlorine solution.
• Advantages/disadvantages of using calcium hypochlorite
(HTH) vs. NaDCC tablets for chlorine (ease of use vs.
availability/cost).

22. Tablet Chlorination System for Tanks
• Water from pipe - part is diverted and part is chlorinated
• 2 valves manipulated to control flow
• Technician regularly tests mixed finished water
Technician adjusts valves based on results & iterates until
correct residual
• Water then flows to tank, helps even out chlorine levels
Adapted from Langtane and Rainey - Recommendations to USAID/Haiti for LF-Series Tablet Feeder Chlorinators

23. Tablet Chlorinator - Nicaragua
From Fitzpatrick 2008

29. Sanitation and Emergencies

31. MacDonald and Callow 2009

34. Some Sanitation Challenges
• Need to pump out or “desludge” latrines that get heavy
use or that pose threat to groundwater - need
“desludging” equipment & sludge disposal location.
• Need better solutions for odors in high density
spontaneous settlement areas with limited space for
setbacks for latrines.
• In areas prone to flooding, latrines must be elevated
“raised.”

35. Examples of Raised Latrines
Photo by Jerry Carreon/Oxfam

36. Hygiene and Emergencies
• Hygiene education that results in increased
handwashing, sanitation and use of treated
water is a powerful means to reduce diarrheal
disease outbreaks during emergencies.

37. Risk factors for Cholera - Zambia
Sasaki et al (2008) Spatial Analysis of Risk Factor of Cholera Outbreak for 2003–2004 in a Peri-urban
Area of Lusaka, Zambia Am. J. Trop. Med. Hyg., 79(3), pp. 414–421

41. Haiti - Hygiene Communication Challenges
• Effectively establishing as consistent
message/understanding that cholera can come back as
strong during/after the rainy season(s).
• Proper dosing of NaDCC tablets (because of the different
products (manufacturers/dosages) being used.
• Building awareness that the solid waste situation in
urban areas can contribute to drainage related flooding
increasing cholera risk (due to drains clogged with
trash).

42. Case Study: Safe Water and 2 Emergencies
Haiti 2010 - 2011

43. Emergency 1 – 2010 Earthquake

44. One Approach Used to Provide Safe Water
Post-Earthquake
• A mix of bladder tanks and “Tuff”
tanks were installed along with
piping, tapstands, , etc. at
spontaneous settlements “camps”
and at orphanages.
• Oxfam contracted with company to
use project dedicated water tanker
trucks to haul water from a deep
well to a number of locations.

45. One Approach Used to Provide Safe Water
Post-Earthquake (cont.)
• Oxfam made up fixed amounts of chlorine in bottles
and provided them on a daily-every other day basis
to camp water committee members
trained to add to empty tanks prior
to water being pumped (helps in
mixing) from tanker trucks.
• Chlorine residual at tanks was checked regularly
(usually daily) by Oxfam.

51. Digital Chlorine Analyzers
• Digital colorimeters are the
most accurate way to measure
chlorine residual in the field
but are more expensive than
“pool testers”.
• Chlorine levels were regularly
tested at spontaneous
settlements where Oxfam was
providing chlorinated water

52. Emergency 2 – Cholera Response

53. Cholera Response – Safe Water
• Assisting communities in the repair of broken or partly
functioning gravity flow (spring) systems
• Hand drilling of new wells

54. Cholera Response (cont.)
• Distribution of NADCC tablets with local partners
• Chlorine residual testing at households

55. Cholera Response (cont.)
•Provided digital chlorine meters & user training to
Cholera Treatment Center (CTC) , hospital & Haitian NGO

56. Cholera Response – Safe Water
(continued)
• In new location/office in Nippes area, some of the
newer chlorination approaches discussed in this
presentation will likely be used (April – Sept. 2011).
• An assessment conducted in March indicated that in
general chlorination of community systems was not
being currently practiced which represents a
significant risk during the upcoming rainy season(s).

57. Thanks for listening!
Any questions?