Determination of Water Quality Index and Suitability of Bumbu River for Municipal Water Supply in Lae City, Papua New Guinea

Abstract

The Lae City is Papua New Guinea’s 2nd largest city, situated on the banks of the River Bumbu in Morobe Province. Thousands of families living along the Bumbu river do not have a treated water supply and appropriate toilet facilities. Hence, communities have been using river water as a source of drinking, laundry, cooking, bathing and defecate. Therefore, it is essential to assess the quality of river water to know its suitability for drinking or not by using Water Quality Index (WQI). Water samples were collected at two sampling points, i.e. upstream and downstream of Lae city along the main channel of Bumbu River and analyzed for various parameters viz., pH, Electrical conductivity, Total dissolved solids, Total alkalinity, Total hardness, Calcium and Magnesium. The results exhibited that each parameter measured increased in quantity from upstream to downstream and all above the maximum permissible limits outlined in the PNG Water Quality Guidelines except for pH. Furthermore, WQI obtained for upstream is 157 and downstream is 212 indicated (WQI>100) that Bumbu river water is unsuitable for drinking. However, river water could be used as an alternative source of water to supply to the Lae city after appropriate treatment. The river water needs complete treatment i.e., screening, coagulation, sedimentation, filtration and chlorination process before used for domestic purpose