The quality of ground water depends on various chemical constituents and their concentrations, with the booming of the Hawassa city; the existing situation of the water quality status and the corresponding anthropogenic impacts on the ground water aquifer is questionable. So, the aim of this study was to assess the present status of the groundwater quality on the basis of seasonal variation in Hawella Tulla sub-city, Hawassa. Groundwater samples were collected during the wet and dry seasons of August 2014 and February 2015 from already existing boreholes and various physico-chemical and heavy metals concentration analyses were performed based on standard methods. The acquired results show that ground water samples were generally of good quality. However, the comparative range of results presents pH (7.3 - 7.9), total hardness (45-114 mg/l), calcium hardness (21-66 mg/l), alkalinity (101-169 mg/l), magnesium hardness (23.5-53 mg/l), fluoride (0.22 -1.07 mg/l), nitrate (1.1-13.2 mg/l), phosphate (0.07-2.15 mg/l) and chromium (0.01-0.03 mg/l) water in the two seasonal extremes. The analysis reports presents that, virtually all the parameters lies within the maximum permissible limit prescribed by WHO except, alkalinity which is above the permissible level, but this value does not have any impression for the water to use for drinking and industrial purpose. However, it is highly essential to examine the presence of toxic substances in distributing water for potable purpose before it is used for drinking.

Keywords: Hawella Tulla, Physicochemical; fluoride; water quality