American Journal of Water Resources, 2021, Vol. 9, No. 2, 41-48 Available online at http://pubs.sciepub.com/ajwr/9/2/2 Published by Science and Education Publishing DOI:10.12691/ajwr-9-2-2 Assessment of Groundwater Quality in Abeokuta North, Nigeria Temitayo Oluwayinka Falola 1,* , Ifeoluwa Olanrewaju Adetoro 2 , Olufemi Abiola Idowu 2 1 Department of Chemistry, Illinois State University, Campus Box 4160 Normal, Illinois 61790-4160, U.S.A 2 Department of Water Resources Management and Agrometeorology, Federal University of Agriculture, Abeokuta, Ogun, Nigeria *Corresponding author: Received May 22, 2021; Revised June 28, 2021; Accepted July 08, 2021 Abstract Background and Objective: Groundwater (hand-dug wells) is the major source of water for municipal use in the Abeokuta North Local Government of Nigeria. However, there is a tendency for its quality to deviate from recommended standards as most groundwater sources are close to regions prone to erosion and most wells are not usually covered. The adverse effects might creep into the ecosystem and affect human health if a regular check on the quality is not made. Materials and Methods: The geographical location and altitude of the wells’ locations were taken using Global Positioning System (GPS). The sagging of the water drawer’s rope was indicated with a pin, the latter which was used to spot the location. Each instrument employed was inserted into the sample of water as per the procedure. The experiment was carried out at the thirty-six available sites in the region. Results: The moderate pH range (6.30-7.36) can be linked to low values of TDS (352 mg/L) and EC (695 μs/cm). Statistical Pearson correlation analysis shows a clear relationship between parameters at p<0.01 (2-tailed T-test; MSExcel); supported by a linear plot between EC and TDS, and a clustered column chart that compares EC and pH. The overall water quality index (WQI) of the parameters gives an excellent value of 17.20%. Keywords: groundwater, Abeokuta north, global positioning system, pH, total dissolved solids, electrical conductivity, world health organization, water quality index Cite This Article: Temitayo Oluwayinka Falola, Ifeoluwa Olanrewaju Adetoro, and Olufemi Abiola Idowu, “Assessment of Groundwater Quality in Abeokuta North, Nigeria.” American Journal of Water Resources, vol. 9, no. 2 (2021): 41-48. doi: 10.12691/ajwr-9-2-2. 1. Introduction Water is essential for the sustainability of life. Its continuous supply is important to replenish the fluid lost during respiration, perspiration, and urination [1]. Water can be found beneath the soil; this is known as groundwater. Also, groundwater refers to water found in rocks and fractures beneath the earth and a part of the water cycle. It is the body of water derived primarily from percolation and contained in pore spaces of a permeable rock [2]. Groundwater could be formed via natural precipitation from infiltration or indirectly from rivers, and it represents the water in the rocks and fissures of a particular geological formation [3]. Traditionally, hand-dug wells (groundwater) have been the major source of drinking water in developing countries. However, because they are dug by hand, their use is restricted to suitable types of ground such as clays, sands, gravels, and mixed soils where only small boulders are encountered. Furthermore, leaching from waste dumps and industries makes them susceptible to contamination due to runoff [4]. Water quality describes the physical, chemical, and microbiological characteristics of water. All these determine the purposes for which the water can be used [5]. These properties could be natural with a particular water source or arise from dissolved or suspended substances from human activities [5]. We cannot live without water and municipal activities can impact its quality and quantity [6]. Fresh groundwater is associated with recharge areas, whilst groundwater is more mineralized. The United Nation goal of access to safe drinking water, especially in developing countries is frequently under threat due to the occurrence of pollutants in drinking water which pose a serious health hazard [7]. pH is one of the most important water quality parameters; although, it has no direct impact on consumers. However, the water of a very low pH is likely to be corrosive to its environment. Corrosion can contaminate water and have adverse effects on its taste and appearance [8]. The pH in the range 6.5-8.5 is usually acceptable, although the nature of the construction materials used in the distribution system as well as the composition of the water both lower and increase this range [9]. In an extreme case, a surge in the pH value could be because of accidental spills, treatment breakdowns, and insufficiently cured cement mortar pipe linings, among others [10]. The dissolved ions in the water sample must be of a low concentration. The electrical conductivity of water