Assessment Of Groundwater Contamination Using The World Health Organization Sanitary Risk Inspection Protocol In Urban Areas In Ghana
Date
2017-07
Authors
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Publisher
University of Ghana
Abstract
Introduction: In the last decade, there has been a significant increase in urbanisation with
its attendant increase in demand for most social amenities including water. The relevant
company is unable to meet the unending demand for pipe water. They are only capable of
supplying intermittent and limited access to piped water especially in urban and peri-urban
areas. These issues have caused most households in the urban and peri-urban areas to resort
to the use of groundwater sources from wells and bore holes for their domestic activities.
Although there are existing observational checklists for identifying potential contamination
hazards around groundwater sources, these checklists were designed for rural rather than
urban areas. It has therefore become necessary to update the checklist to include other
contamination hazards peculiar to urban areas which are not in the existing checklist.
Objective: To assess the replicability of an expanded sanitary risk inspection checklist for
use in urban and peri- urban areas.
Method: This was a cross sectional study carried out in urban and peri-urban communities
in the Greater Accra region. The study sample of 62 wells were recruited after seeking
approval from their owners. Structured questionnaire including the expanded sanitary risk
inspection checklist was used to collect data on demographics, anthropogenic activities and
possible hazards around the well. To evaluate the replicability of the updated checklist, two
independent inspections were done in each household to identify the contamination hazards
around urban and peri-urban groundwater sources concurrently.
A sample of the well water in each household was taken for laboratory work to check for
the presence of total\faecal coliforms. Distribution of background characteristics are
presented in frequencies, percentages, and averages. A binary logistic regression was used
to test the association and effects of the possible hazards on the presence of total\faecal
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coliforms. Area Under Receiver Operating Characteristic Curve (AUROC) was used to
assess the model performance. Cohen Kapa test was used to test for agreement between
responses of the two independent inspectors.
Results: More than half of the wells were contaminated with total coliform and faecal
coliforms (65% and 63% respectively). Among the hazards, holes in cement floors, ponding
within 3m, waste floors, within 3m, polythene in blocked storm and the presence of algae
in blocked drain were as significantly associated with the presence of Total coliform in and
around water. The presence of faecal coliform was associated with rain prior to study day,
faecal in blocked storm drain and the presence of blocked storm drain within 30 m of the
well. Anthropological activities found to influence the presence of faecal coliform in
groundwater were washing of clothes, washing of cars and farming around wells while none
of the human activities has any relationship with presence of total coliform. Replicability
results have shown that there is a very high level of agreement between independent by
different individuals working in the same locations.
Conclusion: Most of the groundwater sources in urban and peri-urban areas are
contaminated according to the World Health Organisation (WHO) standards.
Anthropogenic activities around the wells contributed to the contamination of the
groundwater. The level of replicability among the inspectors indicates that it is possible to expand the inspection checklist to include the urban and peri-urban hazards.
Description
Thesis (MPH)
Keywords
Assessment, Groundwater Contamination, World Health Organization, Sanitary Risk Inspection Protocol, Urban Areas, Ghana