The dam was developed in 2009 by Earthwatch with funding from Tyco International Ltd. Villagers from the Nkaroni community in the Samburu region of northern Kenya had previously faced a five hour trek for water to shallow wells on dry river beds as existing dams were heavily silted and only held water for brief periods. The community identified the Silango Nasham Nkainito dam as historically the most important and a Project Implementation Committee was set up with help from the community-based organisation, Resource Projects Kenya.
The dam now provides clean water for both humans and livestock, filtering contaminated water and improving its quality. As well as helping to reduce child mortality rates, it is mitigating human-wildlife conflicts as the water used for livestock during the daytime is available for wildlife at night.
An initial study carried out by Earthwatch scientists in Kenya had shown that the water sourcing the dam was polluted with human and animal faeces from upstream. In December 2009, after the improvements had been made, filtered water samples were collected from the dam over a period of four days. The samples were taken for bacteriological analysis to the Earthwatch laboratory at Wamba Catholic Mission Hospital where findings showed a 98.951 per cent reduction of total coliforms1 after filtration using the Nkaroni dam filtration system.
The percentage reduction of total coliforms after filtration using laboratory models was only 96.25 per cent, which means that the dam filtration system has been scientifically proven as a successful method for improving access to safe drinking water for people in remote regions.
Dr Nick Oguge, Country Director of Earthwatch Kenya, said: "The Nkaroni dam filtration system was far more efficient than the laboratory models. This could be due to the time taken for water to sediment, and the amount of sand in the filters. The Kenyan government now has a policy on increasing rainwater harvesting, using pans and dams, as a means of increasing accessibility, so we are now in a position to inform on how simple, cost effective and safe filtration systems can be developed. We will be engaging the Ministries of Water and Public Health to share this important finding and how it can be incorporated in existing pans and dams around the country. If properly implemented and used, this may significantly reduce incidences of water-borne diarrheal diseases currently ranking only second to pneumonia as a major infant killer in the country."
During the next phase of the project, the scientists will use several layers of filtration material and experiment with medicinal plants for 100 per cent success.
Waterborne diseases contribute between 70 and 80 per cent of health problems in developing countries, including Kenya. As water can carry a number of different microorganisms to a large number of people and over wide areas, early detection of contamination is crucial. In the recent past there has been an outbreak of waterborne diseases in northern Kenya, including the Samburu region. Diseases linked to drinking water contaminated by human waste include cholera, typhoid and dysentery.
Read more about the commissioning of the dam.
1 Coliform is the name of a test adopted in 1914 by the Public Health Service for the Enterobacteriaceae family. It is the commonly-used bacterial indicator of the sanitary quality of food and water.
Tests on the water filtration system of a model dam developed by Earthwatch are paving the way for improved access to safe drinking water in remote regions of Kenya.