Microbiological risk assessment and management of shallow groundwater sources in Lichinga, Mozambique

Abstract

The principal water target of the Millennium Development Goals (MDG) is to ensure environmental sustainability by halving the proportion of people without access to safe water by 2015. Although great strides have been made in meeting this challenge since the year 2000, the safety of many of these water supplies remains unknown. Acknowledging the weaknesses of current water quality and hydrogeological means of assuring microbial safety, this paper has the objective of developing improved methods for the assessment and management of microbiological water safety based on a ‘risk’ paradigm. This paper provides evidence for the risk assessment of both conventional aquifer pathways and localised (short circuiting) pathways to 25 wells of three well technology types in Mozambique between 2002 and 2005.* Findings from the research outline improve methods of risk assessment and management by demonstrating that (1) the predominant source of contamination was from animal faeces rather than from latrines/septic tanks, (2) short circuiting is a significant risk to shallow groundwater in developing countries, (3) the use of alternative indicator organisms (e.g. enterococci) may improve risk understanding and (4) the World Health Organisation Water Safety Plans are recommended as an appropriate method of risk management.

Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

“…with fewer groundwater sources being relied on towards the end of the dry season there is greater risk of contamination, e.g. from materials used for drawing water, especially for unimproved sources (Godfrey et al 2006). For boreholes this contamination pathway is generally not a major risk factor and this supports the generally better quality found in these types of sources.…”

“…Open and unlined wells are consistently of poorer quality compared to lined or 'improved' wells (e.g. Godfrey et al 2006;Sorensen et al 2015b). Boreholes generally have the best water quality, however in some studies springs have been found to be of better quality compared to boreholes (e.g.…”

An assessment of microbiological water quality of six water source categories in north-east Uganda

“…Each "yes" answer corresponds to an aspect of poor construction or maintenance. Some authors (for example, Howard et al 2003;Godfrey et al 2006) have used statistical methods to link specific questions in sanitary surveys to water quality, although they each concentrated on only one source type (protected springs and covered hand dug wells, respectively). This paper aims to assess the safety of improved water sources in terms of microbiological water quality by comparing the water quality of six different source types, four of which are improved according to the JMP (2008) definition (boreholes, protected springs, roofwater harvesting and covered hand dug wells) and two of which are unimproved (open hand dug wells and open water).…”

Sanitary Hazards and Microbial Quality of Open Dug Wells in the Maldives Islands

“…Nevertheless, unsanitary conditions of the well and the well head area can also permit the rapid ingress of pathogens into well water [5][6][7][8][9]. The microbial contamination of well water can be analyzed using the source-pathway-receptor relationship where, source is the origin of the pathogens; pathway is the route through which the pathogens reach the well water; and, the receptor is the well water.…”