Factors Influencing the Shallow Groundwater Quality in Four Districts with Different Characteristics in Urban Area (Douala, Cameroon)

Abstract

This study examines groundwater samples from four areas under different conditions. Variations amongst the areas are due to the distinct topography, demographics, and socio-economic activities. A qualification of the groundwater using the following parameters; pH, electric conductivity and nitrate analysis yielded results depicting the deplorable state of the unconfined aquifer; which is even worst in the densely populated and low-lying areas. These unfavorable conditions are present in the older districts (Bependa and Ndogbong) compared to the younger and least populated (urbanized) districts (Ndogpassi and Logpom). The poor quality of groundwater could be due to contamination by sewage from latrines and surface discharges. Nevertheless, nitrate contents (>241 mg/l) in these districts indicate that pollution has not reached the alarming levels observed in other West African cities (nitrates > 400 mg/l). Relatively low concentrations of nitrate in groundwater of the studied areas could be due to volatilization phenomena common in the unconfined aquifers in Douala. We however remarked that most of the studied wells are not used as drinking water, because they present particular health risks to humans.

Physico-chemical and Bacteriological Characterization of Groundwater for Domestic and Irrigation Purposes in Santchou (Cameroon Western Highlands)

“…The action of microorganisms, the proximity of latrines and other anthropogenic factors may also influence the pH of water [36]. The pH levels corroborated with values documented in Melong by Mufur et al [13] and in Bamenda by Akoanung et al [4] but were very low compared to those obtained by Ketchemen-Tandia et al [37] in Douala (Littoral Cameroon) and Mukhopadhyay et al [38] in West Bengal. Electrical Conductivity values for all the water samples ranged from 0.05 to 0.25 during the rainy period whereas during the dry period it varied between 0.08 and 0.38 µS/cm.…”

Health Risk of the Shallow Groundwater and Its Suitability for Drinking Purpose in Tongchuan, China

“…Studies performed in the northwest of China reported high nitrate concentrations representing health risk concerns for the population [38] due to anthropogenic activities, especially fertilizers used in agriculture [39]. N-bearing and P-bearing fertilizers can cause the oxidation of geogenic Cr, which results in elevated Cr 6+ [19]. Wei et al [34] also reported that nitrate pollution was a major environmental geological problem in the groundwater in part of China.…”

“…There is a critical increase in freshwater demand correlated with the rapid growth of the population all over the world [14] and intensive agriculture activities [15,16]. The increment of the population also leads to the expansion of cities and municipal waste that affect the groundwater quality through organic and inorganic contaminants [17][18][19][20]. Furthermore, industrialization is one of the most significant factors affecting groundwater quality through the effluents released into the nature [21][22][23][24].…”

Assessment of the quality of quaternary groundwater under the influence of anthropogenic activities in the low-income neighbourhoods of the Treichville municipality (Abidjan, Côte d’Ivoire)

“…Indeed, much urban growth occurs in or around already overcrowded urban shantytowns, periurban areas and informal settlements [24]. Thus, in these low-income neighbourhoods, groundwater contamination is attributed to surface water percolation, septic tanks, cesspools, and latrines using animal manure stored in landfills or applied to agricultural land as fertilizer [15,30,33,34,42,53].…”