Earth Science Malaysia (ESMY)

The objectives of study was to determine hydrochemistry of groundwater in Okitipupa and environs to assess the quality of groundwater for drinking, domestic and irrigation. A total of 27 groundwater samples were collected randomly from different sources and analyzed for major cations and anions. The domination of cations and anions was in the order of K>Na>Ca>Mg and SO4>Cl >HCO3>NO3. The hydrogeochemical facies indicate three dominant facies: non-carbonate hardness exceeds 50 %; non-carbonate alkali exceeds 50 %; and transition zone with no one cation-anion pair exceeds 50 %, while precipitation is the dominant process in the hydrogeochemical evolution of the groundwater samples. The WQI calculated exhibits good (60 %) and poor (40 %) quality water for drinking and domestic purposes. For irrigation assessment, residual sodium carbonate values revealed good irrigation, permeability index values indicates suitable and marginal class, sodium absorption ratio, Kelly ratio, and %Na indicate good irrigation water. The processes controlling the groundwater chemistry are mixing of saline with fresh water and anthropogenic contamination; weathering and cation exchange; mineral precipitation/anthropogenic pollution; and groundwater dilution and mineral dissolution. Consequently the water is fairly suitable for drinking/domestic, and good for irrigation purposes.