Influence of Anthropogenic Activities of Groundwater from Hand Dug Wells within the Precarious Settlements of Southern Abidjan, Côte d'Ivoire: Case of the Slums of Anoumabo (Marcory) and Adjouffou (Port-Bouët)
Journal of Water Resource and Protection
This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums-Anoumabo (Marcory) and Adjouffou (Port-Bouët), both located in the southern part of the city. Twentyeight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies-the Ébrié lagoon and the Atlantic Ocean. The water samples were also tested for
... re also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO 4 , Ca-Cl and Ca-SO 4 . Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO 3 > 50 mg/ℓ). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems. This shortage has led to the over-abstraction and contamination of groundwater resources in some parts of the town. Recent studies show that the vast surface water bodies, the Ébrié lagoon and the Atlantic ocean, which serves as direct source of water to the population and also indirectly as recharge sources to water wells are also threatened and faced with serious pollution problems     . Though, a natural renewable resource, the geochemi-Copyright © 2013 SciRes. JWARP I. OSEMWEGIE ET AL. 428 The Study Area Abidjan has four distinct morphological components, these are: the coastal belt, the petit-Bassam peninsula, the Ébrié lagoon and the plateau running from south to Figure 1. Map showing the local geology of the study area, samples were collected from areas marked with the red dots.