PHYSICO-CHEMICAL AND MICROBIAL QUALITY OF DRINKING WATER IN WOLISO TOWN, SOUTH WEST SHOA ZONE, OROMIA, ETHIOPIA

Abstract

In Ethiopia, access to improved water supply and sanitation was estimated at 52% and 28%, respectively. Over 60-80% of the communicable diseases are arising from unsafe and inadequate water supply, poor hygiene condition and lack of regular treatment of water. This study was conducted to assess the microbial and physicochemical quality of drinking water in Woliso Town. The study was conducted from February 2016 to May 2016. A total of 51 water samples were collected from disinfected reservoirs, household water taps and household water tankers. The bacteriological analysis demonstrated that all the water samples in the study area had aerobic mesophilic bacteria, coliforms, faecal coliforms, faecal streptococci and Cryptosporidium parvum oocysts. The mean counts of AMBC, TCC, and FCC ranged from 5.45-6.43 log CFU/100ml, 3.85-5.64 log CFU/100 ml, and 3.52-4.32 CFU/100ml, respectively.The water samples were also analyzed for the presence of E. histolytia, Giardia, Cryptosporidium, yeasts & moulds. In addition, the physico-chemical parameters such as turbidity, temperature, pH, total hardness, fluorides iron and manganese contents of the drinking water were evaluated. With respect to parasitological analysis, only 5.88% of the tap water samples were positive for Cryptosporidium parvum while none of the water samples examined contained E. histolytica and Giardia lamblia cysts. The mean yeast and mould counts were also ranging from 0.285 -1.14CFU/100ml and 0.714-6.714CFU/100ml respectively. This study revealed that all water samples analyzed did not meet the acceptable bacteriological limits of safe drinking water set by WHO and ES guidelines. Nonetheless, all water samples had reasonable bacteriological quality. The study also showed that most of the physico-chemical parameters were within the range recommended for drinking water of WHO guidelines except temperature which exceeded the WHO standard of less than 15oC. On the basis of these findings, recommendation is made to responsible authorities of Woliso town to implement effective water treatment methods to produce microbiologically safe drinking water in the area.