Articles · Open Access Policy
Abstract
The objective of the research was to describe groundwater and surface water hydrochemistry, understand its variability, identify possible sources of contamination, and estimate its suitability. In total, 12 samples were collected at six groundwater and surface water sites in the dry and wet seasons using a stratified sampling method. Hydrochemical analysis included measurements of physicochemical properties, major ions, and nutrient concentrations. Verification of the charge balance, construction of Piper diagrams, correlation and principal component analysis, as well as spatial assessment, provided a basis for hydrochemical interpretation. Irrigation suitability was estimated through electrical conductivity and sodium adsorption ratio values. Water pH varied from 6.8 to 8.1, electrical conductivity from 520 to 1,280 μS/cm, and nitrate from 3.2 to 38.6 mg/L. The average value of the conductivity decreased from 957 μS/cm in the dry season to 708 μS/cm in the wet season. GW4 had the highest values of conductivity, total dissolved solids concentration (819 mg/L), and sodium adsorption ratio (8.7). Charge balance errors varied between -3.8% and +4.2%. There were three principal components that described 78.4% of total variance. Sodium and chloride were positively correlated (r = 0.84). Calcium-magnesium-bicarbonate and calcium-magnesium-chloride dominated facies pointed toward mineral dissolution whereas local enrichments signified possible anthropogenic impacts like farming and wastewater discharge. Seasonal dilution, along with geological activities, had impacted the water chemistry, while human interventions might have caused the local contamination. GW4 and SW2 needed to be monitored for priority. Recharge area protection, wastewater management, fertilizer management, and seasonal monitoring were suggested, while more investigation was needed to identify the sources of pollution.