Improved microbial risk assessment of groundwater

The World Health Organisation (WHO) and the United Nations Children’s Fund (UNICEF) estimate that at the beginning of the year 2000, one-sixth (1.1 billion) of the world’s population lacked access to a safe water supply (WHO/UNICEF 2000). Despite global efforts made in the decade between 1980–1990, the majority of the worlds’ population with access to safe water remains in developed countries (see Fig. 1). To address the inadequate level of coverage of safe water supply in developing countries, the United Nations established various initiatives including the Millennium Development Goals (MDGs) and the development of a Global Rapid Assessment of Drinking Water Quality Methodology (WHO/UNICEF 2000). The principal target of the MDGs is to Ensure environmental sustainability by halving the proportion of people without access to safe water by 2015 – where safe water is defined as a water supply that is devoid of disease-producing pathogenic bacteria/viruses and highly toxic substances (WHO/ UNICEF 2000; Howard et al. 2001). Due to the high cost and questionable sustainability of piped water supply in developing countries, many rural and peri-urban communities are solely reliant on water supply from shallow groundwater. This essay discusses appropriate methods for assessing and managing the “safety” of this shallow groundwater in developing countries. It will: 1. Acknowledge the increasing global importance of chemical contamination, 2. Highlight the significance of assessment of the vulnerability of groundwater to microbial contamination, 3. Emphasise the specific challenges faced by hydrogeologists in assessing microbial risk in the future.