Chemical quality and water quality indices of Fiche drinking water, Oromia, Ethiopia

The problem of drinking water quality is common in developing countries. While a piped water supply is available in many parts of Fiche, Ethiopia, the water may be contaminated in the distribution system and thus continuous quality assessment is required to ensure safe drinking water for the community. Instrumental and spectrophotometric methods were used to analyze the chemical characteristics including dissolved oxygen, pH, temperature, chloride, fluoride, nitrate, nitrite, sulfate, ammonia, iron and manganese. The weighted arithmetic water quality index method was applied to assess the water's quality rating. The chemical characteristics of the tap water's annual range was; temperature between 19.4 and 20.0°C, pH between 6.8 and 7.6, DO between 4.5 and 6.1 mg/L, ammonia between 0.01 and 0.2 mg-NH3/L, nitrate between 1.1 and 1.8 mg-NO3−/L, nitrite between 0.003 and 0.06 mg-NO2−/L, 2.0 and 19.1 mg-SO42−/L, chloride between 10.07 and 30.0 mg-Cl−/L, manganese between 0.003 and 0.003 mg-Mn/L, iron between 0.01 and 0.03 mg-Fe/L. The WQIs for the reservoir and tap water were 25.031 and 40.676, respectively, so the tap water is rated ‘good’ for drinking.