Assessment of Spatial Variation of Physicochemical Parameters of Groundwater in Some Communities of Yenagoa Metropolis

Water is a basic need of life, and more so, potable water is critical for healthy living. Shallow boreholes are now popular as the main source of drinking water in the Yenagoa metropolis due to the contamination of surface water and rainwater caused by poor management of wastes and crude oil facilities in the area. However, there are concerns about variations in the quality of groundwater across communities in the Yenagoa metropolis. Thus, this study assesses the spatial variations of physicochemical parameters of groundwater samples from 50 boreholes in the area, and results compared with recommended standards prescribed by the World Health Organization (WHO). Parameters analyzed were pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), nitrate, chloride, sulfate, total alkalinity (TA), total hardness (TH), calcium, magnesium, sodium, potassium, and iron. Global Information System (GIS) technology was adopted to present the groundwater quality in respect to each physicochemical parameter, in thematic maps. The maps showed that groundwater was slightly acidic in most communities in Central and Northern Yenagoa like Ekeki, Swali, Akaba, and Okolobiri. In communities like Ogbogoro, Ekeki, Azikoro and Yenegwe the EC was higher than the standard permissible value according to the WHO. A very high concentration of iron was observed across all communities except a few like Nedogo, Okolobiri, Tombia, Gbarantoru, Ayama, Famgbe, and Ikibiri having iron-free groundwater. Concentrations of TDS, calcium, magnesium, nitrates, sulfates, potassium, and sodium were within permissible limits across all communities. Communities like Ayama-Ijaw, Obololi, Ikibiri, Ikudu, Bomodi, Tombia, and Akaibiri had good groundwater while Ekeki, Famgbe, Yenaka, and Kpansia boast of excellent groundwater quality, and other areas had either poor or unsuitable groundwater for consumption. Treatment is recommended for parameters with higher concentrations than the standard value stipulated by the WHO.