IMPROVED GROUNDWATER RISK ASSESSMENT IN DEVELOPING COUNTRIES

The WHO/UNICEF 2000 Global Water Supply and Sanitation Assessment stated that only 47% of the population of rural areas in Africa, 62% in Latin America and 75% in Asia have access to safe water. The predominant source of safe water in many of these rural areas is shallow groundwater. However, increasing global concern over the safety of these water supplies has arisen due to the increased detection of toxic organic chemicals and high levels of pathogenic microorganisms.

Globally, the assurance of microbial safe water has been the priority. In the groundwater sector, this has however historically been assured through reliance on good engineering practice and safe distance from faecal sources. This paper challenges this viewpoint, arguing that the determination of “safe” water in developing countries cannot rely on these factors alone and that greater attention should be paid to assuring microbial safety through an analysis of risk. The paper discusses two principle pathways to risk; namely aquifer and localised pathways. It emphasises the importance of localised pathways that result from short circuiting of well headworks by microbial contaminants.

The paper further suggests that the challenge facing hydrogeologists is to establish appropriate methods to effectively assess and manage this microbial risk in developing countries. Building on experience from Bangladesh, Ghana, India, Mongolia, Mozambique and Uganda, the paper discusses methods for assessing groundwater pathways of risk as well as methods for applying the WHO recommended risk management framework, termed Water Safety Plans (WSP).