Abstract:
Access to safe drinking water is one of the basic human rights and is critical to health.
However, approximately 900 people in the world still do not get their drinking water from
safe sources where the sub-Saharan Africa accounts for over one third of this number. It is
estimated that 80% of all illnesses in the world are related to use of unsafe and
contaminated water. A longitudinal study was conducted from August 2022 to February
2023 in three selected Ambo, Toke Kutaye and Jibat woredas (districts) of central highland
of Ethiopia. Water samples were collected once a month for three consecutive months in
both wet and dry seasons, and examined for E.coli and Enterococci CFU/100ml to
investigate the sanitary inspection as a risk assessment tool by estimating the microbial
load of Faecal Indicator Bacteria (FIB) and selected physicochemical parameter; Water
Temperature (WT), potential of Hydrogen ion (pH), Dissolved Oxygen (DO), Electrical
conductivity (EC), available total phosphorus (P), nitrite (NO2
-
) and nitrate (NO3
-
). The
risk of watersources were assessed using the sanitary inspection checklist adopted from
the World Health Organization (WHO). For this investigation, a total of 78 water samples
from 13 Dug-wells were collected. The results were interpreted using WHO guideline and
Compulsory Ethiopian Standard (CES for drinking water quality. A total of 78 drinking
water samples showed contamination with Escherichia coli and only two samples were
negative for Enterococci. Nitrate and Nitrite concentration ion of all samples were below
the WHO and ESA's permitted level for drinking water use. Based on WHO criteria, 61%
of water sources were grouped into high and very high risk. Drainage faulty, drainage
channel crack and absence of plat (the concrete floor) with trunk were significantly
associated with water contamination rate. Our findings suggest that most water sources
in the studied woreda’s of Western Shewa Zone, Oromia Region are contaminated by
faecal coliforms. Therefore, regular sanitary inspection, bacteriological analysis, well constructed drainage channels and trunk are advocated to protect drinking water sources
from faecal contamination.
