PATHOGEN PATHWAYS, CONTAMINATION, AND SUSTAINABLE WATER RESOURCE SOLUTIONS FOR HAITI
Many shallow karst aquifers, and virtually all surface water in rural Haiti, are subject to contamination and recontamination by fecal bacteria and other pathogens. In March 2011, samples of water sources from rural Haiti were collected and analyzed for Escherichia coli (E. coli) and total coliform bacteria using the IDEXX Quanti-Tray® method. Samples were analyzed from surface water, undeveloped springs, developed springs, water reservoirs, shallow hand-dug wells, shallow sealed wells with hand pumps, and deep wells accessed with mechanized pumps.
E. coli counts ranged from zero to over 38,000 colony forming units (cfu)/100 ml, and total coliform levels ranged from zero to greater than 240,000 cfu/100ml. Average E. coli bacterial counts from unsealed hand-dug wells were one thousand times greater than sealed hand pump wells. Water samples from deep wells did not reveal significant contamination of deep aquifers, even in areas where shallow aquifer contamination was present. Springs, both developed and undeveloped, had average contamination levels which were one hundred and fifty times greater than sealed hand pump wells. Surface water quality was highly variable, but on average, had contamination levels over eighteen hundred times greater than sealed hand pump wells.
Properly constructed, sealed, and maintained hand pump wells are clearly a good solution for providing safe and sustainable water resources in Haiti. Hand dug well use should be discouraged and existing hand dug wells should be converted to sealed pump wells or sealed and abandoned. Developed and undeveloped spring sources that emerge near streams should be replaced with shallow pump wells with proper seals and filter pack material when possible.