Dynamic Distribution of Physicochemical and Bacteriological Characteristics of Water Samples from Water Supply Sources in Rural Settlements of Ibarapa East Local Government Area, Oyo State, Nigeria

Abstract

Purpose: This study aimed at examining the dynamic distribution of physicochemical and bacteriological characteristics of water samples from water supply sources in rural settlements of Ibarapa East Local Government Area of Oyo State, Nigeria.

Methodology: A Systematic random sampling technique was adopted in the selection of five rural settlements namely: Adiekola (AD), Maya (MA), Akeete (AK), Okolo (OK) and Alapa (AL). Two water supply sources were randomly sampled in each of the settlements. In all, ten water samples were collected from Hand Pump Boreholes (HPBHs), Motorised Boreholes (MBHs), Hand-Dug Wells (HDWs) and a Stream (STR) using standard sampling procedures. Geographic coordinates of the water sources were obtained using a Global Positioning System (GPS), while the Average Nearest Neighbour (ANN) analysis in ArcGIS was employed to determine the spatial distribution of water supply sources. Physicochemical and bacteriological parameters of the water samples were subjected to laboratory analysis using the universally acceptable laboratory procedures. The results were compared with WHO drinking water quality standards.

Findings: The results revealed that water supply sources exhibited a weakly clustered spatial pattern indicating an uneven distribution of water infrastructure and disparities in access to potable water across the study area. Most physicochemical parameters, including pH, temperature, electrical conductivity, total dissolved solids, total hardness, nitrate, sulphate, phosphate, calcium and potassium, were within WHO permissible limits. However, elevated turbidity was recorded in the Hand-Dug Well at Adiekola (AD2) and the stream at Akeete (AK 2), while dissolved oxygen values were below the recommended standard in all samples. Iron concentrations exceeded the WHO limit in five water samples, and manganese concentrations exceeded the permissible limit in the stream and one Hand-Dug Well. Bacteriological analysis revealed contamination of Hand-Dug Wells and the Stream with Bacillus spp., Salmonella spp. and Escherichia coli, accompanied by high total coliform counts, whereas most Motorised and Hand Pump Boreholes recorded zero coliform counts and no detectable pathogenic bacteria. The results indicated that protected boreholes generally provide safer drinking water than hand-dug wells and surface water sources. Therefore, it was suggested that water from the contaminated sources should be adequately treated before consumption while improved sanitation infrastructure and protection of water sources are necessary to safeguard public health in the study area.

Unique Contribution to Theory, Practice and Policy: This study contributes to the understanding of rural water quality by integrating geospatial analysis with physicochemical and bacteriological assessments to evaluate both the accessibility and safety of rural water supply sources. Theoretically, it advances the application of spatial analytical techniques in rural water quality assessment by linking infrastructure distribution with water quality status. Practically, the findings provide baseline information for prioritising water quality monitoring, groundwater protection and community-based water safety interventions in rural communities. From a policy perspective, the study provides empirical evidence to support equitable spatial planning of water infrastructure, routine water quality surveillance, rehabilitation of contaminated water sources, and to strengthen implementation of rural water supply and sanitation policies aimed at providing adequate access to safe and clean drinking water.