RESEARCH ARTICLE
Comparative Bacteriological and Heavy Metal Toxicity Evaluation of Groundwater Wells Proximal to Pollution Receiving Streams in Ondo City, Nigeria
Olufemi J. Akinnifesi1, *, Joseph O. Akinneye1
Article Information
Identifiers and Pagination:
Year: 2019Volume: 13
First Page: 315
Last Page: 323
Publisher ID: TOMICROJ-13-315
DOI: 10.2174/1874285801913020315
Article History:
Received Date: 03/07/2019Revision Received Date: 26/11/2019
Acceptance Date: 27/11/2019
Electronic publication date: 31/12/2019
Collection year: 2019
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Background:
Groundwater is the main and easily accessible source of water supply. Aside its over-exploitation problems, groundwater has undergone quality challenges-owing to its proximity to pollution sources.
Methods and Materials:
This study assessed the quality of hand-dug wells situated close to the pollution receiving streams in the Ondo City. Thirty water samples; from fifteen hand-dug wells and fifteen closely associated streams across the city were collected for the study. Physico-chemical, microbial and heavy metals parameters were comparatively analyzed in stream and groundwater samples to assess percolation impact on groundwater quality. Studies were carried out in wet and dry seasons.
Results:
The results obtained from the wells water show that beside temperature and PH, the mean values of other physicochemical parameters like turbidity (111.47 NTU & 68.77 NTU/), total dissolved solid (474.6 mg/l & 68.77mg/l), and electrical conductivity (822.31 µS/cm & 816.79 µS/cm) in both season respectively were above the World Health Organisation (WHO) highest desirable limits. The highest total coliform (T.col) recorded at 11,200 (cfu/100ml) and 11,300 (cfu/100ml) and Faecal coliform at 8,400 (cfu/100ml) and 12,100 (cfu/100ml) for dry and rainy seasons respectively. Highest level of aluminium, cadmium, lead, and chromium concentrations in well water at 1.632mg/l, 0.820mg/l, 0.079mg/l and 0.079mg/l recorded in the rainy season exceeded WHO’s recommendations. Pearson Correlation analysis between well and stream in the dry season shows positive correlation for all water parameters, with strong significance in PH, turbidity, faecal coliform and chromium concentration (0.544, 0.914, 0.414 &0.597) respectively. Similarly, in the rainy season, both well and stream had positive correlations for most parameter tested with significances in turbidity, electrical conductivity, total dissolved solid and cadmium concentration (0.708, 0.775, 0.766&0.655) respectively.
Conclusion:
The major outcome of this research revealed most water samples (well and stream) failed quality assessments. The positive correlations between wells and polluted stream parameters suggested that distance contributed significantly to well contaminations.
