Assessment of heavy metal pollution on groundwater quality in the Niger Delta Region of Nigeria

Heavy metal (HM) pollution in groundwater poses a significant environmental threat to the Niger Delta region of Nigeria, principally because of the activities of oil companies within the locality. The current study considered it necessary to measure the HM level in the groundwater of this location. 18 groundwater samples were collected and tested for physical parameters (pH, EC, TDS), as well as heavy metals (Cr, Cu, Zn, Co, Fe, Mn, B, Ni, and Cd). Results from the principal component analysis (PCA) analysis reveal the influence of heavy metals on groundwater chemistry. The correlation matrix results showed that there exists a weak and positive correlation among elements, revealing that heavy metals in water with a low pH tend to be more toxic, as they become more soluble and bioavailable. HM pollution assessment results revealed that the values were considered low, with values ranging from 0 to 0.33 with an average value of 0.07. Metal pollution index (MPI) results showed that the groundwater sample was very pure. Nemerow Pollution Index (PNI) results revealed that the groundwater samples were heavily polluted. Results from the modified degree of contamination (MCd), showed that the majority of the samples had a very low degree of contamination. The pollution load index (PLI) results indicated that the entire samples were polluted. Quantification of contamination (QoC) results showed a geogenic impact on the samples. Based on the findings, monitoring groundwater quality and using appropriate treatment technologies to purify the water before consumption are recommended.