Quality of Surface and Ground Water in Three States of Nigeria: Assessment of Physicochemical Characteristics and Selected Contamination Patterns

The study of water quality is crucial given the amount of industrial, agricultural, and other human activities in the sampling sites. The aim of the study was to assess the physicochemical characteristics and heavy metals contamination of water samples in Nigeria. This study used conventional analytical techniques to analyze the physicochemical parameters in water samples from 33 sampling sites (dug wells, boreholes, rivers, and rainwater) in three different states (Ekiti, Osun, and Ondo) of Nigeria. These parameters included pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), Temperature, Relative Humidity (RH), and four elemental parameters (Ca, Na, Fe, and Cu). The Enrichment Factor (EF), Contamination Factor (CF), and Metal Index (MI) were used to characterize the data. Temperature (28.17^oC), TDS (130.2 mg/L), EC (260.0 μS/cm), pH (6.88), Na (14.47 ppm), Ca (25.74 ppm), Fe (0.49 ppm), and Cu (0.08 ppm) were the average values from the results. Na and Ca had relationships with one another. The levels of heavy metals were below those recommended by the Standard Organization of Nigeria (SON) and the World Health Organization (WHO). The metal levels in the water samples were over 1.5, which is the threshold value indicated by the EF classifications. Particularly, EFs were moderate to significantly enriched. All element CFs were below the 1-level pollution threshold. The water samples are pure based on the MI's rating of water quality. Human and natural activities may represent a risk to the local public health, hence it is highly advised that all stakeholders adopt rapid and long-lasting collective action to limit pollution levels as part of the water quality governance system.