This study evaluates the physico-chemical properties of groundwater in Ogbia, Bayelsa State, Nigeria. Standard field and laboratory methods were followed. The results of the study revealed that the pH value ranges from 6.4 to 7.1 with an average of 6.86 indicating a slightly acidic condition. The concentration level of iron in the study area ranges from 0.1mg/l to 4.2mg/l with a mean value of 1.89mg/l. 13.3% of iron in sampled locations satisfy the World Health Organization (WHO) and Nigerian Standards for Drinking Water Quality (NSDWQ) highest desirable level of 0.3mg/l. The concentration of calcium ranges between 3.0mg/l to 13.1mg/l, with a mean value of 8.83mg/l, while magnesium concentration was from 1.8mg/l to 9.0mg/l, with a mean value of 5.6mg/l. The concentration level of phosphate in the study area ranges from 0.02mg/l to 0.19mg/l, with a mean value of 0.12mg/l. Chloride concentration level in the sampled locations was between 10mg/l to 39mg/l, with a mean of value of 23.8mg/l, all the values recorded were within the permissible WHO and NSDWQ standard of 250mg/l. The low concentration level of chloride in the area indicates that there is no salt water intrusion, hence all the locations have freshwater. The cations were in order of abundance as Na+ > Ca 2+ > Mg 2+ > Fe 2+ > Mn 2+, while anions were in the order of abundance as SO4 > Cl > NO3 > F > NH3 > PO4. Piper Trilinear Diagram for the study area showed that there were mixtures of two types of water with variable concentrations of major ions. These were sodium-chloride type and sodium- sulphate type of water, an indication that the water was from a marine source. Based on the result from this study, there is the need for regular ground water quality monitoring and effective management strategies in the area.
Hydrochemistry of River Owan water and groundwater in its vicinity were examined to decipher their quality status and evaluate the impact of man on the coastal area of the river. Twelve River Owan water and three groundwater samples were subjected to hydrochemical and bacteriological investigations using standard methods. Temperature, pH and electrical conductivity were measured insitu employing pH Testr Meter. The waters were alkaline (average pH of 9.27) signifying a slight trend of alkaline chemical reaction within the system. Electrical resistivity (EC) was virtually less than 1000µS/cm in all water samples indicating fresh water. The dominance of the major ions was as Na+ > Ca2+ >Mg2+ > K+ and HCO3− > Cl− > SO42− > NO3−. The average values of major ions (mg/L) in the order of dominance were 23.15, 11.56, 9.25, 9.07 and 79.63, 48.92, 29.18, 5.49 respectively. Total hardness of the water revealed that 12 out of 15 water samples were under soft water category ( TH ). All water samples tested positive to bacterial infection (1.60*102 e-coli 8.10*103 Cfu/ml). Anthropogenic activities dominated ionic sources in River Owan while that of the groundwater was mainly geogenic. Much of the natural character of the coastal environment of River Owan has been modified by human activities. Hygiene education of the public must be encouraged in order to ameliorate the unhygienic status of River Owan.