Evaluation of Groundwater Quality Using Multivariate Statistical Techniques, in Dashen Area, North Eastern Nigeria

Abstract

The aim of this research is to assess groundwater quality of Dashen and environs for irrigational and domestic purposes using multivariate techniques. Twelve water samples were collected from boreholes and hand-dug wells. The water samples were analysed for major cations: Na+, Ca2+, K+, Mg2+ and anions: Cl-, HCO3-, SO42- and CO32-. The order of abundance of the cations concentration is in order of* Ca2+> Mg2+> K+> Na+ while those of the anions are HCO3-> Cl->SO42->CO32-. The important constituents that influence the water quality for irrigation such as Electrical Conductivity (EC), Total Hardness (TH), Total Dissolved Solids (TDS), Sodium Adsorption Ratio (SAR), Magnesium Ratio (MR), Percentage Sodium (%Na), Permeability Index (PI), Kelley Ratio (KR), Residual Sodium Bicarbonate (RSBC), and Soluble Sodium Percentage (SSP) were assessed and compared with standard values. The values of TH (21.4 – 53.3 mg/l), EC (54 – 383 μS/cm), %Na (3.0 – 9.5%), SSP (3.0 – 9.5%), MR (40.1 – 48.9%), KR (0.003 – 0.067 meq/l), RSBC (-1.6 – 1.9 meq/l) and SAR (0.01 – 0.2 meq/l) were found to be within the safe limits and thus suitable for irrigation purposes. Permeability Index (41.5 – 100.7%) and total dissolved solids (80 – 580 mg/l) range from best quality water to water involving hazards. Piper diagram classified water in the study area as Ca2+- Mg2+- HCO3- facies. The multivariate statistical analysis using PCA and HCA identified diffused form of contamination, leaching of bed rock geochemistry, salinity, natural mineralization and anthropgenic contamination, as the major processes controlling the groundwater chemistry. The overall water quality index indicates that water is suitable for human consumption.