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
Displacement of Large Numbers of People Increases the Likelihood of Waterborne Disease Outbreaks
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.
A Number of Waterborne Pathogens Cause Increased Diarrhea Cases During Flooding From Harris et al. 2008
Community Water Sources Before and After Flooding Haiti (Gonaives) 2004 From Colindres et al. 2007
Cholera Outbreak - 1994• Between July 14 and 17, 1994 approximately800,000 ethnic Hutus fled Rwanda and sought refugein neighboring Zaire (now DRC). Many refugeesentered through the town of Goma, at the northernend of Lake Kivu.• A massive cholera outbreak spread quickly and veryhigh death rates resulted. The hard volcanic soilprevented the building of traditional latrines andLake Kivu which was used for bathing and drinkingquickly became contaminated with cholera (GomaEpidemiology Group,1995).
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.
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.
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.
One NaDCC Manufacturers Varying Doses for Household Use Medentech
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
Potential New Approaches to Chlorination of Community Systems during Emergencies
Point of Water Collection Chlorine DispenserFrom: Trickle Down: Chlorine Dispensers and Household Water Treatment byKremer et al. 2009
Challenges for Making Chlorination at WaterCollection 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).
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
Tablet Chlorinator - Nicaragua From Fitzpatrick 2008
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.”
Examples of Raised Latrines Photo by Jerry Carreon/Oxfam
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.
Risk factors for Cholera - ZambiaSasaki 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
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).
Case Study: Safe Water and 2 Emergencies Haiti 2010 - 2011
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.
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.
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
Cholera Response – Safe Water• Assisting communities in the repair of broken or partlyfunctioning gravity flow (spring) systems • Hand drilling of new wells
Cholera Response (cont.)• Distribution of NADCC tablets with local partners• Chlorine residual testing at households
Cholera Response (cont.)•Provided digital chlorine meters & user training to Cholera Treatment Center (CTC) , hospital & Haitian NGO
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).