Safe drinking water is of great importance to ensure the protection of public health. Both microbial and inorganic contaminants can be a threat to human health, particularly in Sub-Saharan Africa, where a large proportion of the population do not have access to a treated water supply. This study investigated the temporal variation of drinking water quality over nine months at five rural groundwater sources in Lilongwe, Malawi. The sources comprised three hand pumped boreholes, one open shallow well and one shallow well with a hand pump fitted. Three methods of detecting microbial contamination were employed, comprising traditional incubation, thermotolerant coliform and Escherichia coli culturing methods and an emerging rapid assessment method using tryptophan-like fluorescence technology. Inorganic hydrochemical parameters measured include temperature, turbidity, pH, conductivity, alkalinity, nitrate, fluoride, sulphate, chloride and dissolved organic carbon.
The results highlight the variability of drinking water quality in terms of seasonality and source type, with implications for risks to human health. The different methods of detecting microbial contamination are compared, drawing conclusions on suitability of application and resolution of results. Advantages and disadvantages of the different methods will be discussed in relation to the current World Health Organisation drinking water quality guidelines.