Hydrochemical analysis of groundwater quality along the coastal aquifers in part of Ogun Waterside, Ogun State, southwestern Nigeria

Abstract

Hydrochemical investigation of groundwater was carried out on the coastal aquifers of Ogun Waterside, Southwestern Nigeria. Groundwater samples were collected and assayed for physicochemical parameters during wet season (August, 2016) and dry season (March, 2017). The analysed data were further subjected to correlation analysis (CA), principal component analysis (PCA), hydrochemical facies and descriptive statistics. Results revealed that the groundwater is slightly acidic with fresh to saline character. The CA showed very strong associations between TDS, EC and Cl concentrations in both wet and dry seasons. PCA confirmed the main factor influencing the groundwater chemistry in the study area to be component I (salinity component). Piper plots also revealed that the aquifer is mainly of water type. Schoeller and Stiff diagrams showed that the groundwater comprises relative abundance of major ions in the following order: for the cations and for the anions. Thus, the primary process influencing the hydrochemistry of the study area is saltwater invasion while mineral dissolution and rainwater infiltration play less significant roles. Most parameters fall within the permissible limit proposed by the World Health Organization (2011) and Nigerian Standard for Drinking Water Quality (2007). However, higher concentrations of chloride and bicarbonate ions observed towards the southern flank of the study area suggest signs of impairment. Assessment of the sampled water for agricultural purposes with respect to salinity hazard, Total Hardness (TH), percentage sodium (%Na) and Sodium Adsorption Ratio (SAR) revealed that the water is suitable for agricultural activities.

Evaluation of the Hydrochemical and Water Quality Characteristics of an Aquifer Located in an Urbanized Area

“…This dominance could be related to progressive evaporation and ion exchange processes [43]. The lower-right ternary plot (anion diagram) indicated that the groundwater chemistry of the Cuernavaca aquifer is highly influenced by Calcium-bicarbonate type and Bicarbonate type [44]. These results are consistent with the results suggested by other researchers [45].…”

Conceptualization of Pollution of Groundwater Resources in Ilaje Area, Nigeria, West Africa: Contribution From Hydrogeochemical and Numerical Index Techniques

“…CaHCO 3 is the least dominant facie, represented by two (7%) wells, which depicts silicate mineral dissolution from reaction between rock and water and recharge of rainfall(Mondal and Singh, 2012, Asiwaju-Bello et al, 2020). This also indicates the dominance of alkaline earths and weak acid anions(Badmus et al, 2020). The NaHCO 3 and CaHCO 3 facies occurrence show that there was dissolution of silicates and carbonates and a simultaneous ion exchange(Oyedele et al, 2019).…”

Groundwater Distribution in Urban Settlement

“…In addition, included in the factors are improper sealing of abandoned boreholes and reduced access of rural indigenous people in coastal areas (especially in the oil-producing areas) to potable water supply due to perceived lack of freshwater resources in these areas [26]. Hydrochemical analysis of groundwater quality along the coastal aquifers in part of Ogun Waterside, Ogun State, southwestern Nigeria [28] indicated a Na-Cl dominated water exhibiting slightly acidic with fresh to the saline character. More detailed hydrogeophysical studies are required in the coastal areas of Nigeria to determine the hydrogeology and the nature as well as extent of saltwater intrusion to ameliorate and prevent further encroachment of saltwater.…”