Physico-Chemical Characteristics and Heavy Metals in Groundwater Bassambiri-Nembe, Bayelsa State, Nigeria

Abstract

The study is focused on the post impact of oil spill contamination o f groundwater in Bassambiri Nembe Bayelsa State. Groundwater samples were sampled from hand dug wells from eight stations including the control point for phys ico-chemical investigation using sterilized glass bottles. Standa rd methods were used for the analyses. The result of physico-chemical parameters analyzed shows that the values of the groundwater pH ranged between 5.90 - 6.35, electrical conductivity between 80.39 - 89.23 μS/cm, Salinity 23.3 - 28.69 mg/l, Turbidity 1.71 - 3.84 NTU, Biochemical Oxygen Demand (BOD) 1.12 - 1.36 mg/l, Alkalinity 8.56 - 12.12 mg/l, Total Hardness 11.8 - 14.47 mg/l and Temperature 26.1 ℃ - 27.3 ℃ . Analysis of cations shows that Na ranged from 7.38 - 10.34 mg/l, K 0.26 - 0.49 mg/l, Calcium ion levels 2.56 - 3.59 mg/l and Mg 0.88 mg/l - 1.23 mg/l. The anions showed Potassium ion levels ranged from 0.01 mg/l - 0.02 mg/l, Chloride ion levels 12.29 mg/l - 15.88 mg/l, Fluoride ion levels 0.01 mg/l and Nitrates from 0.27 mg/l - 0.48 mg/l. Total Hete rotopic Fungi population ranged from 15.26 - 48.55 Coliform Formin g units/ml. The maximum permissible value of total coliforms in drinking water was exceeded. However, the Total Hydrocarbon Concentration (THC) across the gro undwater sample points w as less than 0.01 mg/l. The concentration of PAH and BTEX was 0.01 mg/l across the study area. The heavy metal concentrations in the groundwater samples w ere negligible with levels of 0.01 mg/l observed in the study area except for iron ranging from 0.20 - 0.56 mg/l levels above the WHO permissible limit. The physico-chemical parameters of groundwater indicate that they fall below WHO permissible limits. The cations and anions concentration indicate a stable and healthy water system which is relatively good. The groundwater system has high levels of iron in groundw ater and bacterial contamination. Treatment is required to a void acute an d chronic iron overload resulting from consumption fro m drinking groundwater within the study area.