Thesis-2006-Godfrey.pdf (47.14 MB)
Microbiological risk assessment and management of shallow groundwater sources in Lichinga, Mozambique
thesis
posted on 2011-01-21, 11:39 authored by Sam GodfreyThe 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
in terms of provision of services since the year 2000, the safety of many these water
supplies remains unknown. One of the biggest challenges therefore facing water
development professionals is how to ensure sufficient levels of both quantity and
guality of safe water. One of the principal mechanisms for monitoring the progress
towards attaining the MDG goals for access to safe water is the UNICEF/WHO Joint
Monitoring Programme (JMP).
However, the JMP acknowledges that one of its current weaknesses is in assessing
safety related to different technology types. In acknowledgement of these weaknesses
and of the weakness of reliance on "end product testing" as a means of assuring
microbiological safety, the thesis proposes improved methods of assessment and
management of microbiological water safety based on a "risk" paradigm. Coinciding
with proposed new risk based methods of assessing water safety outlined in the 3d
edition of the World Health Organization Guidelines for Drinking Water Quality
(2004), the thesis researches the risk to three well technology types in Mozambique.
Principal pathways to microbiological contamination of shallow groundwater were
assessed which included both the conventional aquifer pathways and preferential or
localised pathways.
The research adopted an experimental design that uses a mix of qualitative and
quantitative data collection techniques. Data were collected over 12 months in 25 well
sites in Lichinga, Mozambique. Findings from the research demonstrated that risk
assessment and management are effective tools in understanding the level of safety
associated with the well technologies under study. The research indicated firstly that
risk assessment aids the identification of specific risk variables (of which animal
faeces is a predominant risk), secondly that the use of alternative indicator organisms
(e.g. enterococci) may improve risk understanding, thirdly that there is a strong
statistical correlation between use of surrogates (e. g. turbidity) and microbes and
fourthly that Water Safety Plans are an appropriate method of risk management.
Furthermore, the research supports the JMP definitions of improved water sources, which suggest that upgraded wells are not an improved source due to their high
vulnerability to contamination through localised pathways.
The recommendations from the thesis include; non-inclusion of upgraded wells in the
JMP in Mozambique, greater use of enterococci and turbidity as surrogate indicators
of faecal pollution, the need for the development of rapid risk assessment and
management techniques for rural areas in developing countries and the inclusion of
localised pathways as a principal route of assessment. Potential areas of further
research include field-based studies of assessment of faecal sources of Enterococci
bacteria, and rapid methods for the development of model Water Safety Plans.
History
School
- Architecture, Building and Civil Engineering
Publisher
© Sam GodfreyPublication date
2006Notes
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.429828Language
- en