Assessment of microbiological and physico-chemical quality of drinking water in North Gondar Zone, Northwest Ethiopia

Abstract

Introduction: Assessing the microbiological and physico-chemical quality of drinking water sources is important to protect public health. Little is known about the microbiological and physico-chemical quality of drinking water in North Gondar Zone. Therefore, this study was aimed to assess the microbiological and physico-chemical quality of drinking water sources in North Gondar Zone, Northwest Ethiopia. Methods: A cross-sectional study was conducted from April to May 2014 in seven districts (Chilga, Debark, Dabat, Dembia, Gondar Town, Gondar Zuria and Wogera) in North Gondar. The physico-chemical and microbiological quality of 71 drinking water samples were determined following the standard procedure. Turbidity, pH, and temperature were measured using a turbidity meter, pH meter, and thermometer, respectively. Arsenic, chlorine, Cr 6 +, NO 2 , NO 3 and residual chlorine were determined by the colorimetric methods and rapid kits using disruptive pattern material apparatus (Kyoritsu chemical-check Lab., Corp. Japan). Coliforms and Vibrio parahemolyticus were tested by rapid microbiological test strips (Sankori coliform and Sankori V. parahaemolyticus) following appropriate standard procedure. Consumer's assessment was also conducted using a questionnaire about the water sources. Data were entered and analyzed using SPSS version 20 software. Results: The physicochemical and microbiological quality of 71 water samples (tap n = 29, spring n = 15 and well n = 27) were assessed. The mean turbidity of water samples was 19.35 ± 5.75 standard deviation nephelometric turbidity unit, temperature 21.34 ± 3.68°C, pH 6.88 ± 0.6, nitrate 10.02 ± 8.72 mg/l, nitrite 0.33 ± 0.64 mg/l, residual chlorine 0.01 ± 0.06 mg/l, arsenic 0.2 ± 0.00 mg/l, and chromium 0.51 ± 0.01 mg/l. Almost all samples were complying with the World Health Organization acceptable range for nitrate arsenic and chromium among the physico-chemical parameters. However, turbidity was found to be unacceptably high in 21 (29.6%) samples, pH was unacceptably low in 26 (36.6%) of the samples and residual chlorine was unacceptably low in 69 (97.2%) of the samples. The majority of samples (n = 46; 64.8%) had coliforms, and 12 (16.9%) had V. parahemolyticus. Conclusion: Most of the physical and chemical parameters measured were within the recommended range except turbidity and residual chlorine. However, the majorities of drinking water samples were found to be contaminated and were potential risk to public health. Therefore, regular quality monitoring and frequent water treatment in the study area is mandatory.

Assessment of Bacteriological and Physicochemical Quality of Drinking Water from Source to Household Tap Connection in Nekemte, Oromia, Ethiopia

“…The results showed that average temperature records of the water samples range from 20.5 to 20.8 C without showing significant difference among the sources (Table 1). Similarly, earlier studies in Gondar zone [12] and Bahir Dar [17] reported a mean temperature of 21.3 C and 23.8 C, respectively. In tropics, the climate is characterized by high temperature and rainfall, and these factors might have contributed to the high temperature records of water samples from different cities of Ethiopia that did not meet the WHO standard of <15 C [18].…”

“…Our results showed that the temperature of the tap water samples ranged between 16.8°C and 22.1°C without showing any significant difference among the sites (Table 3) and hence did not meet the WHO standard of <15°C [18]. Likewise, similar earlier studies [8, 12] reported higher temperature values in drinking water from different Ethiopian cities. The pH of tap water samples varied from 6.6 to 7.0 (Table 3) without any significance among the sampling points.…”

Bacteriological and Physicochemical Quality of Drinking Water in Wegeda Town, Northwest Ethiopia

“…Similarly, studies conducted in the different localities of Ethiopia such as in Bahir Dar town [ 8 ], Dire Dawa [ 20 ], north Gonder [ 21 ], Jimma town [ 7 ], Sidama Zone [ 9 ], Shambu town [ 22 ], and Nekemte town [ 12 ] have shown a high level of coliform counts that did not meet the WHO permissible level. This implies that bacterial contamination of drinking water continues to be a public health concern in Ethiopia.…”

Bacteriological and physical quality of Fiche drinking water from households and reservoirs, Oromia, Ethiopia

“…The materials used to store water at home for days are highly suitable for the growth of anaerobic organisms. Several studies conducted in Ethiopia on the physicochemical and bacteriological quality of drinking water from various sources indicated that water sources were contaminated with pollution indicators such as fecal and total coliforms (APHA 1998; Mengesha et al 2004;Birhanu 2007;Temesgen & Hameed 2009;Milkiyas et al 2011;Solomon et al 2011;Debasu et al 2014;Yasin et al 2015;Gonfa et al 2019;Alemnew & Seyoum 2020;Matusala et al 2020).…”