Sustainable Safe Water solutions for Haiti
Safe and Sustainable Treatment Methods for Haiti.
Providing safe and sustainable water in Haiti is complicated by geologic, ecologic, sociologic, and economic factors. Those seeking to help provide clean water to Haiti must consider and address these factors to provide safe and sustainable water for Haiti. These four factors are interrelated in complex ways that make solutions complex, and by their nature interdisciplinary and transdisciplinary.
The geology of Haiti consists of a core of igneous rocks which forms the backbone of the island of Hispaniola and the border between Haiti and the Dominican republic. This core is surrounded in much of the mountains by sedimentary rocks consisting of limestones and shales. Limestones have fissures and fractures which have been enlarged by dissolution in a process referred to as karstification or simply karst. The karst aquifers are particularly prone to contamination with water-borne pathogens. Near major rivers and in the large basin occupied by Port au Prince sufficient alluvium has accumulated to form alluvial fans and alluvial aquifers. These aquifers, although more effective at filtering pathogens than karst limestone are prone to contamination from long term sanitation and industrial practices.
One of the most common things people think of when someone mentions Haiti is poverty, but running a close second is deforestation, soil erosion, and a generally devastated ecosystem. What people may not think of is the microbiotic ecosystem which is an integral part of the macrobiotic ecosystem which has also been devastated. Both the microbiotic and macrobiotic (trees and plants) provide a first line of defense for protecting groundwater in Haiti from contamination.
Attitudes and perceptions of water in Haiti are affected by religious attitudes, historic practices, and the general educational level of most rural Haitians. Many Haitians who practice Voodoo view water as sacred. Waterfalls and springs are generally viewed as sacred places in Voodoo for their natural beauty and provision. Catholicism also views water as sacred but in a way more connected to God and the cleansing power of water. Both of these viewpoints are predisposed to view water as clean and sacred even when it is contaminated with pathogens that can kill, especially when those pathogens are not visible and the water appears clean.
Haiti is a very impoverished country with many people living close to the edge of survival. Water in large cities is often provided by central systems of fountains. Many also buy water that has been treated in bottles and bags. In the mountains of Haiti central water systems and bottled water are not available so many drink untreated water from springs. A simple solution for ensuring the safety of this water would be to boil all water but many do not have the money to buy fuel for sterilizing water and cooking their meals. Many are also unaware that the water is unsafe because it looks clean and may be collected from a spring emerging from a rock.
Table 1 below is a summary of treatment methods applied in Haiti and other countries. This list is continually evolving so if you have suggestions or additional methods please e-mail me at email@example.com.
Table 1. Treatment methods used in Haiti and other developing countries.
Passive Solar Disinfection
|Cheap; reuse bottles; simple||Water is warm; have to wait for water; turbidity sensitive||$||High|
|Plastic Biosand Filters||Effective; once primed provide quick water treatment||Time needed to develop biofilm; skill required to maintain; support needed; turbidity sensitive||$$$$$||Moderate||http://www.hydraid.org/|
|Concrete Biosand Filters||Effective; once primed provide quick water; can usually be built in country with local materials||Heavy and difficult to transport and move; skill required; turbidity sensitive||$$$$||Moderate||Biosand Filter.org Fact Sheet|
|Chlorine||Very effective when used properly; cheap||Bad taste to water; skill required; potential negative health impacts; doses vary depending on product being used||$||High||http://www.ag.ndsu.edu/pubs/h2oqual/watsys/ae1046w.htm|
Rolling Boil for 1-3 minutes
|Very effective at killing most pathogens||Expensive; contributes to deforestation; have to cool water before drinking||$$$||Moderate||http://wwwnc.cdc.gov/travel/page/water-treatment.htm|
|Reverse Osmosis||Very effective at removing all pathogens||Very expensive; requires consistent fuel or power; skill required; maintenance required||$$$$$$||Low||Water Treatment Notes from Cornell University|
Easy to use when proper education materials are provided
|Expensive; may have to sterilize filters regularly; not well suited for areas with turbid water; backwashing can cause contamination||$$$||Moderate||http://www.sawyer.com/water.htm|
|Clay Filters||Cheap and can be made from local materials||Clay quality can affect treatment; skill required; may not be effective for some viruses and bacteria||$||High||http://www.pottersforpeace.org/?page_id=9|
|Ultraviolet Disinfection||Very effective; power requirements low (~ 200 watts for 40 gpm)||Flow rates low; can be complicated to install; maintenance required for bulbs||$$$$||High/Moderate|
|Slow sand filtration||Can be scaled to larger water sources for schools and communities||Initial costs are high and require materials which may not be available on-site||$$$$||High/Moderate||Tech Brief from the National Environmental Services Center|
|Ozone Disinfection||Does not create harmful byproducts; does not alter taste; no residual chemicals||On-site equipment required is expensive and requires maintenance; ozone is reactive and corrosive||$$$$$$||Low||EPA fact sheet on Ozone Dissinfection|
Page last modified April 16, 2013