Evaluation of Groundwater Quality in Parts of Ondo State, Southwestern, Nigeria

Abstract

Groundwater is an essential resource for drinking, and its quality is critical to human health. This study examines the physical and chemical quality of drinking water in eight Local Government Areas (LGAs) in Ondo State. The water quality analysis methodology outlined in the APHA and USGS water standard guidelines was incorporated into the methodology used in this study. On-site parameters such as pH, EC, TDS, and temperature, as well as the primary physical and chemical properties of groundwater samples, were investigated. According to the water analysis results, the study's findings indicate that the water samples' temperatures ranged from 27 to 29 degrees Celsius. The pH ranges from 6 to 7. The turbidity falls between 1.2 and 1.6 NTU. The range of electrical conductivity (EC) is between 80 and 90 µS/cm. Each water sample in the study area has a TSS of 0.01. Idanre had the lowest TDS (40 mg/L), while Okitipupa had the highest (45 mg/L). Idanre has the lowest water hardness, at around 45 mg/L, while Akure and Okitipupa have the highest, at 50 mg/L. Idanre reported 17 mg/L of chloride, while Ikare and Okitipupa reported 20 mg/L. Except for Idanre, all groundwater samples examined had a nitrate concentration of 9 mg/L. Phosphate concentrations were less than 0.01 mg/L in all the samples. Sulphate concentrations were evaluated. Iron concentration ranges from 0.07 mg/L to 0.10 mg/L. The evaluated groundwater falls within the acceptable limit of the World Health Organization's (WHO) Groundwater Quality Index.