Assessment of bacteriological quality of groundwater from boreholes in Maroua (Far North Cameroon)

Abstract

Groundwater (e.g. from wells and boreholes) represents an important source for water supply for populations in Maroua, Far north Cameroon. Although its consumption is being accentuated by the limited access to potable water, the quality of water from boreholes is unknown by the consumers. This study aimed at assessing the bacteriological quality of groundwater from boreholes in Maroua, in order to determine the impact of anthropogenic pressure and to measure the sanitary risks to which people who use them as drinking water sources are exposed. A total of 18 boreholes were chosen as sampling sites for bimonthly analyses (from October 2016 to January 2017). Microbiological analyses comprised the prevalence of total coliforms (TCs), Escherichia coli and Heterotrophic Aerobic and Mesophilic Bacteria (HAMB). Some physico-chemical parameters including temperature, pH, electrical conductivity, total dissolved solids (TDSs), salinity, dissolved CO 2 were measured to characterize these waters and to determine their influence on the bacterial flora. The results showed that the pH of the water of the 18 boreholes varied from 6.3 to 7.5 CU; the lower value of temperature was 25.9 °C and the higher was 31.2 °C. The values of electrical conductivity, TDSs and Salinity fluctuated from 171.5 to 1910.3 µS/cm, 119.4 to 1331.3 mg/l and 79.2 to 970.3 ppm respectively in the water samples of these boreholes. The concentration of dissolved CO 2 varied from 9.5 to 27.8 mg/l of water. From these results, 72.2% of analysed water samples were contaminated by the total coliforms and E. coli. The water contamination would be the consequence of the proximity of boreholes with latrines and domestic wastes. There is a need to educate the public about the quality of their water sources and the importance of clean and healthy surroundings near water sources and to implement household water treatment to improve the water quality and reduce waterborne diseases.

Factors Affecting the Persistence of Cholera Epidemics in Bibémi (North Cameroon)

“…The absence of V. cholerae at the other sampling sites could be explained by the changes in environmental conditions, in other words V. cholerae would be found in a VNC form and in association with other aquatic organisms [5]. This result corroborates the findings of Djaouda et al [19]. However, borehole water trapped in the depths, cut off from any obvious interaction with the external environment, is less favorable to microbial contamination.…”

“…This habitude would be linked to the culture and the low availability of water resources which require making reserves. Not disinfecting water storage containers before filling them could favor the installation of certain microorganisms in biofilms on the container walls and increase the risk of transmission of water-borne diseases [19]. These results are consistent with those of the Bibémi township [13].…”

“…As in the case of salinity, the relatively high values of the electrical conductivity in sites P3 and P8 compared to the other wells could be explained by the presence of mineral contaminants resulting from the degradation of water quality [19]. Regarding the surface water, the high values recorded in mayo-Barka compared to mayo-Lawa would be associated to mineralization of organic matter of various origins [22].…”

“…The water pH at the different sampling points varied from acidic to basic. The slightly acidic nature of the water at some sampling points is linked to the geological nature of the aquifer [19]. Water sources which presented basic water pH were close to human habitation and therefore more exposed to anthropogenic activities.…”

“…The water temperature values recorded for all the studied hydrosystems are above the 25°C limit prescribed in the WHO standards for drinking water. The relatively higher water temperature could be explained by the combination of several factors such as, the sampling period, the season, the sunshine and the depth of the water [19]. These high values favors the microbial development in the aquatic ecosystem.…”